Siemens Simatic S 7 300 - 400 -statement List For S7-300 And S7-400

Preface, Contents Product Overview

1

Structure and Components of Instructions and Statements

2

Adressing

3

Accumulator Operations and Address Register Instructions

4

Bit Logic Instructions

5

Timer Instructions

6

Counter Instructions

7

Load and Transfer Instructions

8

Integer Math Instructions

9

SIMATIC S7 Statement List (STL) for S7-300 and S7-400 Programming Reference manual

This reference manual is part of the documentation package with the order number 6ES7810-4CA04-8BR0

10/98 C79000-G7076-C565 Release 01

Floating-Point Math Instructions

10

Comparison Instructions

11

Conversion Instructions

12

Word Logic Instructions

13

Shift and Rotate Instructions

14

Data Block Instructions

15

Jump Instructions

16

Program Control Instructions

17

Appendix Glossary, Index

Safety Guidelines

!

!

!

This manual contains notices which you should observe to ensure your own personal safety, as well as to protect the product and connected equipment. These notices are highlighted in the manual by a warning triangle and are marked as follows according to the level of danger:

Danger indicates that death, severe personal injury or substantial property damage will result if proper precautions are not taken.

Warning indicates that death, severe personal injury or substantial property damage can result if proper precautions are not taken.

Caution indicates that minor personal injury or property damage can result if proper precautions are not taken.

Note draws your attention to particularly important information on the product, handling the product, or to a particular part of the documentation.

Correct Usage

!

Note the following:

Warning This device and its components may only be used for the applications described in the catalog or the technical description, and only in connection with devices or components from other manufacturers which have been approved or recommended by Siemens. This product can only function correctly and safely if it is transported, stored, set up, and installed correctly, and operated and maintained as recommended.

Trademarks

SIMATIC, SIMATIC HMI

and SIMATIC NET are registered trademarks of SIEMENS AG.

Third parties using for their own purposes any other names in this document which refer to trademarks might infringe upon the rights of the trademark owners.

Copyright  Siemens AG 1998 All rights reserved

Disclaimer of Liability

The reproduction, transmission or use of this document or its contents is not permitted without express written authority. Offenders will be liable for damages. All rights, including rights created by patent grant or registration of a utility model or design, are reserved.

We have checked the contents of this manual for agreement with the hardware and software described. Since deviations cannot be precluded entirely, we cannot guarantee full agreement. However, the data in this manual are reviewed regularly and any necessary corrections included in subsequent editions. Suggestions for improvement are welcomed.

Siemens AG Bereich Automatisierungs- und Antriebstechnik Geschaeftsgebiet Industrie-Automatisierungssysteme Postfach 4848, D-90327 Nuernberg

Siemens Aktiengesellschaft

 Siemens AG 1998 Technical data subject to change. C79000-G7076-C565

Statement List (STL) for S7-300/S7-400

Preface

Purpose

This manual is your guide to creating user programs in the Statement List programming language STL. The manual also includes a reference section that describes the syntax and functions of the language elements of STL.

Audience

This manual is intended for S7 programmers, operators, and maintenance/service personnel. A working knowledge of automation procedures is essential.

Scope of the Manual

This manual is valid for release 5.0 of the STEP 7 programming software package.

Compliance with Standards

STL corresponds to the “Instruction List” language defined in the International Electrotechnical Commission’s standard IEC 1131-3, although there are substantial differences with regard to the operations. For further details, refer to the table of standards in the STEP 7 file NORM_TBL.WRI.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

iii

Preface

Requirements

To use this Statement List manual effectively, you should already be familiar with the theory behind S7 programs which is documented in the online help for STEP 7. The language packages also use the STEP 7 standard software, so you should be familiar with handling this software and have read the accompanying documentation.

Documentation

Purpose

Order Number

STEP 7 Basic Information with






Basic information for technical per- 6ES7810-4CA04-8BA0 Working with STEP 7 V5.0, Getting Started sonnel describing the methods of implementing control tasks with Manual STEP 7 and the S7-300/400 proProgramming with STEP 7 V5.0 grammable controllers. Configuring Hardware and Communication Connections, STEP 7 V5.0


From S5 to S7, Converter Manual STEP 7 Reference with


Ladder Logic (LAD)/Function Block Diagram (FBD)/Statement List (STL) for S7-300/400 manuals


Standard and System Functions for S7-300/400

Online Helps

Provides reference information and 6ES7810-4CA04-8BR0 describes the programming languages LAD, FBD and STL and standard and system functions extending the scope of the STEP 7 basic information.

Purpose

Order Number

Help on STEP 7

Basic information on programming and configuraing hardware with STEP 7 in the form of an online help.

Reference helps on STL/LAD/FBD

Context-sensitive reference informa- Part of the STEP 7 Stantion. dard software.

Reference help on SFBs/SFCs

Part of the STEP 7 Standard software.

Reference help on Organization Blocks

Accessing the Online Help

You can display the online help in the following ways:


Context-sensitive help about the selected object with the menu command Help > Context-Sensitive Help, with the F1 function key, or by clicking the question mark symbol in the toolbar.


Help on STEP 7 via the menu command Help > Contents. References

iv

References to other documentation are indicated by reference numbers in slashes /.../. Using these numbers, you can check the exact title in the References section at the end of the manual.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Preface

SIMATIC Customer Support Online Services

The SIMATIC Customer Support team offers you substantial additional information about SIMATIC products via its online services:


General current information can be obtained: – on the Internet under http://www.ad.siemens.de/simatic/html_00/simatic – via the Fax-Polling number 08765-93 02 77 95 00


Current product information leaflets and downloads which you may find useful are available: – on the Internet under http://www.ad.siemens.de/support/html_00/ – via the Bulletin Board System (BBS) in Nuremberg (SIMATIC Customer Support Mailbox) under the number +49 (911) 895-7100. To dial the mailbox, use a modem with up to V.34 (28.8 Kbps) with the following parameter settings: 8, N, 1, ANSI; or dial via ISDN (x.75, 64 Kbps).

Additional Assistance

If you have other questions, please contact the Siemens representative in your area. The addresses are listed, for example, in catalogs and in Compuserve (go autforum). Our SIMATIC Basic Hotline is also ready to help:


in Nuremberg, Germany – Monday to Friday 07:00 to 17:00 (local time): telephone: +49 (911) 895–7000 – or E-mail: [email protected]


in Johnson City (TN), USA – Monday to Friday 08:00 to 17:00 (local time): telephone: +1 423 461–2522 – or E-mail: [email protected]


in Singapore – Monday to Friday 08:30 to 17:30 (local time): telephone: +65 740–7000 – or E-mail: [email protected] The SIMATIC Premium Hotline is available round the clock worldwide with the SIMATIC card (telephone: +49 (911) 895-7777).

Courses for SIMATIC Products

Siemens offers a number of training courses to introduce you to the SIMATIC S7 automation system. Please contact your regional training center or the central training center in Nuremberg, Germany for details: Telephone: +49 (911) 895-3154.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

v

Preface

Questionnaires on the Manual and Online Help

vi

To help us to provide the best possible documentation for you and future STEP 7 users, we need your support. If you have any comments or suggestions relating to this manual or the online help, please complete the questionnaire at the end of the manual and send it to the address shown. Please include your own personal rating of the documentation.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

iii

1

Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1-1

2

Structure and Components of Instructions and Statements . . . . . . . . . . . . . . . .

2-1

2.1

Structure of a Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-2

2.2

Meaning of the CPU Register in Statements . . . . . . . . . . . . . . . . . . . . . . . . .

2-10

Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-1

3.1

Immediate Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-2

3.2

Direct Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-2

3.3

Memory Indirect Addressing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-3

3.4

Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-6

3.5

Area-Internal Register Indirect Addressing . . . . . . . . . . . . . . . . . . . . . . . . . .

3-7

3.6

Area-Crossing Register Indirect Addressing . . . . . . . . . . . . . . . . . . . . . . . . .

3-11

Accumulator Operations and Address Register Instructions . . . . . . . . . . . . . . . .

4-1

4.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-2

4.2

ENT and LEAVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-3

4.3

Incrementing and Decrementing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-6

4.4

+AR1 und +AR2: Adding a Constant to Address Register 1 or Address Register 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-7

Bit Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-1

5.1

Boolean Bit Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-2

5.2

Bit Logic Instructions and Relay Coil Circuit . . . . . . . . . . . . . . . . . . . . . . . . . .

5-6

5.3

Evaluating Conditions Using And, Or, and Exclusive Or . . . . . . . . . . . . . . .

5-10

5.4

Nesting Expressions and And before Or . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-14

5.5

Instructions for Transitional Contacts: FP, FN . . . . . . . . . . . . . . . . . . . . . . . .

5-16

5.6

Output of Boolean Logic String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-20

5.7

Set and Reset Instructions: S and R . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-21

5.8

Assign Instruction (=) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5-24

5.9

Negating, Setting, Clearing, and Saving the RLO . . . . . . . . . . . . . . . . . . . . .

5-26

3

4

5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

vii

Contents

6

7

8

9

10

viii

Timer Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-1

6.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-2

6.2

Location of a Timer in Memory and Components of a Timer . . . . . . . . . . .

6-3

6.3

Loading, Starting, Resetting, and Enabling a Timer . . . . . . . . . . . . . . . . . . .

6-5

6.4

Timer Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-7

6.5

Address Locations and Ranges for Timer Instructions . . . . . . . . . . . . . . . . .

6-17

6.6

Choosing the Right Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6-18

Counter Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-1

7.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-2

7.2

Setting, Resetting, and Enabling a Counter . . . . . . . . . . . . . . . . . . . . . . . . . .

7-3

7.3

Couting Up and Counting Down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-5

7.4

Loading a Count Value as Integer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-6

7.5

Loading a Count Value in Binary Coded Decimal Format . . . . . . . . . . . . . .

7-7

7.6

Counter Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7-8

7.7

Address Locations and Ranges for Counter Instructions . . . . . . . . . . . . . . .

7-10

Load and Transfer Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-1

8.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-2

8.2

Loading and Transferring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-3

8.3

Reading the Status Word or Transferring to the Status Word . . . . . . . . . . .

8-6

8.4

Loading Times and Counts as Integers . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-7

8.5

Loading Times and Counts in Binary Coded Decimal Format . . . . . . . . . .

8-9

8.6

Loading and Transferring between Address Registers . . . . . . . . . . . . . . . .

8-11

8.7

Loading Data Block Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8-12

Integer Math Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9-1

9.1

Four-Function Math . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9-2

9.2

Adding an Integer to Accumulator 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9-6

Floating-Point Math Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-1

10.1

Four-Function Math . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-2

10.2

Forming the Absolute Value of a Floating-Point Number . . . . . . . . . . . . . . .

10-6

10.3

Extended Math Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-7

10.4

Forming the Square / Square Root of a Floating-Point Number . . . . . . . . .

10-9

10.5

Forming the Natural Logarithm of a Floating-Point Number . . . . . . . . . . . . 10-11

10.6

Forming the Exponential Value of a Floating-Point Number . . . . . . . . . . . . 10-12

10.7

Forming Trigonometric Functions on Angles Acting as Floating-Point Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-13

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Contents

11

12

13

14

15

16

Comparison Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-1

11.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-2

11.2

Comparing Two Integers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-3

11.3

Comparing Two Floating-Point Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . .

11-5

Conversion Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12-1

12.1

Converting Binary Coded Decimal Numbers and Integers . . . . . . . . . . . . .

12-2

12.2

Converting 32-Bit Floating-Point Numbers to 32-Bit Integers . . . . . . . . . . .

12-8

12.3

Reversing the Order of Bytes within Accumulator 1 . . . . . . . . . . . . . . . . . . . 12-13

12.4

Forming Complements and Negating Floating-Point Numbers . . . . . . . . . 12-14

Word Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13-1

13.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13-2

13.2

16-Bit Word Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13-3

13.3

32-Bit Word Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

13-6

Shift and Rotate Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14-1

14.1

Shift Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14-2

14.2

Rotate Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14-6

Data Block Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15-1

15.1

Opening Data Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15-2

15.2

Swapping Data Block Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15-2

15.3

Loading Data Block Lengths and Numbers . . . . . . . . . . . . . . . . . . . . . . . . . .

15-3

Jump Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-1

16.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-2

16.2

Unconditional Jump Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-3

16.3

Conditional Jump Instructions Founded on Result of Logic Operation . . .

16-4

16.4

Conditional Jump Instructions Founded on BR, OV, or OS Bits of the Status Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-5

Conditional Jump Instructions Based on Result in the CC 1 and CC 0 Bits of the Status Word . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-6

Loop Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

16-8

Program Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17-1

17.1

Parameter Assignment when Calling FCs and FBs . . . . . . . . . . . . . . . . . . .

17-2

17.2

Calling Functions and Function Blocks with CALL . . . . . . . . . . . . . . . . . . . .

17-3

17.3

Calling Functions and Function Blocks with CC and UC . . . . . . . . . . . . . . .

17-7

17.4

Working with Master Control Relay Functions . . . . . . . . . . . . . . . . . . . . . . . . 17-10

17.5

Master Control Relay Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-11

17.6

Ending Blocks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17-16

16.5 16.6 17

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

ix

Contents

A

Alphabetical Listing of Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

A-1

A.1

Listing with (German) SIMATIC and International Mnemonics . . . . . . . . . .

A-2

A.2

Alphabetical Listing with International Names . . . . . . . . . . . . . . . . . . . . . . . .

A-12

Programming Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-1

B.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-2

B.2

Bit Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-3

B.3

Timer Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-7

B.4

Counter and Comparison Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-10

B.5

Integer Math Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-12

B.6

Word Logic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

B-14

C

Source Files - Examples and Reserved Keywords . . . . . . . . . . . . . . . . . . . . . . . . .

C-1

D

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

D-1

B

x

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Glossary-1

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index-1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Product Overview

1

What is Statement List?

Statement List (STL) is a textual programming language that can be used to create the code section of logic blocks. Its syntax for statements is similar to assembler language and consists of instructions followed by addresses on which the instructions act.

The Programming Language STL

Of all the programming languages with which you can program S7 controllers, STL is the closest to the machine code MC7 of the S7 CPU. This means that by using it to program S7 controllers, you can optimize the run time and the use of memory. The programming language STL has all the necessary elements for creating a complete user program. It contains a comprehensive range of instructions. A total of over 130 different basic instructions and a wide range of addresses are available. Functions and function blocks allow you to structure your STL program clearly.

The Programming Package

The STL programming package is an integral part of the STEP 7 Standard Software. This means that following the installation of your STEP 7 software, all the editor functions, compiler functions and test/debug functions for STL are available to you. Using STL, you can create your own user program as follows:


With the Incremental Editor. The input of the local data structure is made easier with the help of table editors.


With a source file in the Text Editor. Text input is made easier with the help of block templates. There are three programming languages in the standard software, STL, FBD, and LAD. You can switch from one language to the other almost without restriction and choose the most suitable language for the particular block you are programming. If you write programs in LAD or FBD, you can always switch over to the STL representation. If you convert LAD programs into FBD programs and vice versa, program elements that cannot be represented in the destination language are displayed in STL.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

1-1

1-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

2

Chapter Overview

Page

Section

Description

2.1

Structure of a Statement

2.2

Meaning of the CPU Register in Statements

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-2 2-10

2-1

Structure and Components of Instructions and Statements

2.1

Structure of a Statement

Components of a Statement

With reference to structure, an instruction statement belongs to either one of the following two basic groups (see also Figure 2-1):


A statement made up of an instruction alone (for example, NOT, see Section 5.9)


A statement made up of an instruction and an address (see Tables 2-1 through 2-5, and Table 2-9)

Statement group 1 Instruction alone Figure 2-1

Address of an Instruction

Statement group 2 Instruction + address

Basic Groups of Statements

The address of an instruction indicates a constant or the location where the instruction finds a value (data object) on which to perform an operation. The address can have a symbolic name or an absolute designation. The address can point to any of the following items (see also Tables 2-1 through 2-9):


A constant, the value of a timer or counter, or an ASCII character string to be loaded into accumulator 1 (for example, L +27, see Table 2-1)


A bit in the status word of the programmable logic controller (for example, A UO, see Table 2-2)


A symbolic name (for example, A Motor.On, see Table 2-3)
A data block and a location within the data block area (for example, L DB4.DBD10, see Table 2-4)


A function (FC), function block (FB), integrated system function (SFC), or integrated system function block (SFB) and the number of the function or block (see Table 2-5)


An address identifier and a location within the memory area that is indicated by the address identifier (for example, A I 1.0, or A I [AR1,P#4.3], see Table 2-9) Tables 2-1 through 2-9 show various statements that each include an instruction with an address.

2-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Constant Values

Table 2-1 shows how you can use a constant value as the address of an instruction. Table 2-1

Addresses That Point to a Value or Character String Statement

Instruction

Address

D Description i i

Constant

Locations in the Status Word

L

+27

L

’END’

Load the integer 27 into accumulator 1. Load the ASCII characters ’END’ into accumulator 1.

The address of a statement list instruction can refer to one or more bits in the status word of the programmable logic controller (see Section 2.2). The instruction checks and reacts to the signal state of a single bit in the status word (for example, A BR) or interprets the bit combination in two of the bits (for example, A UO). Table 2-2

Addresses That Refer to a Bit in the Status Word Statement

Instruction

Address

Description

Bit in the Status Word A

BR

The 1 or 0 in bit 8 of the status word is included in a Boolean logic combination.

A

UO

The instruction interprets the bit combination that it finds in bits CC 1 and CC 0 of the status word to see if a certain condition has been fulfilled. For example, a combination of 1 and 1 indicates “unordered,” that is, one of the values in a floating-point operation was not a valid floating-point number.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-3

Structure and Components of Instructions and Statements

Symbolic Name

Table 2-3 shows how you use a symbolic name as the address of an instruction. You can only use symbolic names in STL statements once you have declared them: shared symbolic names should be entered in the symbol table and local names in a block. Table 2-3

Addresses That Point to a Symbolic Name Statement

Instruction

Address

D Description i i

Symbol

A Data Block and a Location within the Data Block

A

Motor.On

Perform an And logic operation on the bit whose symbolic name is “Motor.On”. In this case, the symbolic name “Motor.On” can only represent a bit in the data block (D) area of memory or element of a structure “MOTOR” .

L

SPEED

Load the byte, word, or double word value, whose symbolic name is SPEED, into accumulator 1 .

Table 2-4 shows how you use a data block and a location within the data block as the address of an instruction. Table 2-4

Addresses That Point to a Data Block and a Location within the Data Block Statement

Instruction

Address

Description Descr pt on

Data Block and Location

2-4

L

DB4.DBD10

A

DB10.DBX4.3

Load data double word DBD10 from data block DB4 into accumulator 1. Perform an And logic operation on data bit DBX4.3 from data block DB10.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

FCs, FBs, SFCs, and SFBs

Table 2-5 shows how you use a function (FC), function block (FB), integrated system function (SFC), or integrated system function block (SFB) and the number of the function or block as the address of an instruction. Table 2-5

Addresses That Point to a Function, Function Block, System Function, or System Function Block Statement

Instruction

Address D Description i ti

FC, FB, SFC, SFB and Number

Address Identifiers

CALL

FB10, DB10

CALL

SFC43

Call function block FB10 with instance data block DB10. Call integrated system function SFC43.

Some addresses include an address identifier and a location within the memory area indicated by the address identifier. An address identifier can be one of the following three basic types (see Tables 2-6 through 2-8):


An address identifier that indicates the memory area and the size of a data object in that area as follows (see Table 2-6): – The memory area in which an instruction finds a value (data object) on which to perform an operation (for example, “I” for the process image input area of memory) – The size of the value (data object) on which the instruction is to perform its operation (for example, B for “byte,” W for “word,” and D for “double word”)


An address identifier that indicates a memory area but no size of a data object in that area (for example, an identifier that indicates the area T for “timer,” C for “counter,” or DB or DI for “data block,” plus the number of that timer, counter, or data block, see Table 2-7)


An address identifier that indicates the size of a data object but no memory area. The memory area is encoded in the memory location that follows the address identifier (see Table 2-8).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-5

Structure and Components of Instructions and Statements

Table 2-6

Address Identifier That Indicates Memory Area and Size of Data Object

Type of Addressing

Instruction

Address Identifier Memory Area

Direct

A

I

Direct

L

I

Memory indirect

A

I

Memory indirect

L

I

Area-internal register indirect

A

I

Area-internal register indirect

T

L

Table 2-7

Memory Location

Size of Data Object (If no size is indicated, a bit is implied.) 0.0 B

10 [MD2]

B

[DID4] [AR1, P#4.3]

D

[AR2, P#53.0]

Address Identifier That Indicates Memory Area, but No Size of Data Object Instruction

Address Identifier: Memory Area

Number or Location of Number

Direct

OPN

DB

5

Direct

SP

T

7

Memory indirect

OPN

DB

[LW2]

Memory Indirect

S

C

[MW44]

Type of Addressing

Table 2-8

Address Identifier That Indicates Size of Data Object, but No Memory Area Instruction

Type of Addressing

Area-crossing register indirect

A

Area-crossing register indirect

L

Table 2-9

Size of Data Object (If no size is indicated, a bit is implied.)

Memory Location

[AR1, P#4.3] B

[AR1, P#100.0]

Addresses That Include Address Identifier and Location Statement

Instruction

2-6

Address Address Identifier

Location in Memory Area or Register

A

I

1.0

A

I

[MD2]

L

C

1

D Description i ti

Perform an And logic operation on input bit 1.0. Perform an And logic operation on the input bit whose exact location is in memory double word MD2. Load the count value of counter 1 into accumulator 1.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Working with Word or Double Word as Data Object

If you are working with an instruction whose address identifier indicates a memory area of your programmable logic controller and a data object that is either a word or a double word in size (see Table 2-6), you need to be aware of the fact that the memory location is always referenced as a byte location. This byte location is the number of the most significant byte within the word or double word. For example, the address in the statement shown in Figure 2-2 references four successive bytes in memory area M, starting at byte 10 (MB10) and going through byte 13 (MB13).

Statement: L MD10 Address identifier

Figure 2-2

Byte location

Example of Memory Location Referenced as Byte Location

Figure 2-3 illustrates data objects of the following sizes:


Double word: memory double word MD10
Word: memory words MW10, MW11, and MW13
Byte: memory bytes MB10, MB11, MB12, and MB13 When you use absolute addresses that are a word or a double word in width, make sure that you do not create any byte assignments that overlap.

15

0
15

0

MW10 MB10

MW12 MB11

MB12

MB13 LSB

MSB 31

Figure 2-3

Memory Areas and their Functions

MW11 16
15 MD10

0

Referencing a Memory Location as a Byte Location

Most addresses in STL refer to memory areas. The following table lists the memory areas and describes the function of each area.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-7

Structure and Components of Instructions and Statements

Table 2-10

Memory Areas and Their Functions Access to Area

Name of Area

Function Funct on of Area

via Units of the Following Size:

Abbrev.

Process image input

At the beginning of the scan cycle, the operating system reads the inputs from the process and records the values in this area. The program can use these values in its cyclic processing.

Input bit Input byte Input word Input double word

I IB IW ID

Process image output

During the scan cycle, the program calculates output values and places them in this area. At the end of the scan cycle, the operating system reads the calculated output values from this area and sends them to the process outputs.

Output bit Output byte Output word Output double word

Q QB QW QD

Bit memory

This area provides storage for interim results calculated in the program.

Memory bit Memory byte Memory word Memory double word

M MB MW MD

I/O: external input

This area enables your program to have direct access to input and output modules (that is, peripheral inputs and outputs).

Peripheral input byte Peripheral input word Peripheral input double word

PIB PIW PID

Peripheral output byte Peripheral output word Peripheral output double word

PQB PQW PQD

I/O: external output Timer

Timers are function elements of STL programming. This area provides storage for timer cells. In this area, clock timing accesses time cells to update them by decrementing the time value and timer instructions access time cells.

Timer (T)

T

Counter

Counters are function elements of STL programming. This area provides storage for counters. Counter instructions access them here.

Counter (C)

C

Data block

This area contains data that can be accessed from any block. If you need to have two different data blocks open at the same time, you can open one with the statement “OPN DB” and one with the statement “OPN DI”. In this way, the CPU can distinguish which of the two data blocks your program wants to access while both data blocks are open. While you can use the “OPN DI” statement to open any data block, the principal use of this statement is to open instance data blocks that are associated with function blocks (FBs) and system function blocks (SFBs). For more information on FBs, SFBs, and instance data blocks, see the STEP 7 Online Help.

Data block opened with the statement “OPN DB”:

Data bit Data byte Data word Data double word

DIX DIB DIW DID

This area contains temporary data that is used within a logic block (OB, FB, or FC). These data are also called dynamic local data. They serve as an intermediate buffer. When the logic block is finished, these data are lost. The data are contained in the local data stack (L stack).

Temporary local data bit Temporary local data byte Temporary local data word Temporary local data double word

L LB LW LD

Local data

2-8

Data bit Data byte Data word Data double word

DBX DBB DBW DBD

Data block opened with the statement “OPN DI”:

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Table 2-11 lists the maximum address ranges for various memory areas. For the address range possible with your CPU, refer to the technical data of the CPU. For an explanation of the functions of the memory areas, see Table 2-10. Table 2-11

Memory Areas and Their Address Ranges Access to Area

Name of Area

via Units of the Following Size:

Abbrev.

M i Maximum Address Add Range R

Process image input

Input bit Input byte Input word Input double word

I IB IW ID

0.0 to 65,535.7 0 to 65,535 0 to 65,534 0 to 65,532

Process image output

Output bit Output byte Output word Output double word

Q QB QW QD

0.0 to 65,535.7 0 to 65,535 0 to 65,534 0 to 65,532

Bit memory

Memory bit Memory byte Memory word Memory double Word

M MB MW MD

0.0 to 255.7 0 to 255 0 to 254 0 to 252

I/O: external input

Peripheral input byte Peripheral input word Peripheral input double word

PIB PIW PID

0 to 65,535 0 to 65,534 0 to 65,532

I/O: external output

Peripheral output byte Peripheral output word Peripheral output double word

PQB PQW PQD

0 to 65,535 0 to 65,534 0 to 65,532

Timer

Timer (T)

T

0 to 255

Counter

Counter (C)

C

0 to 255

Data block

Data block opened with the statement “OPN DB”:

DBX DBB DBW DBD

0.0 to 65,535.7 0 to 65,535 0 to 65, 534 0 to 65,532

DIX DIB DIW DID

0.0 to 65,535.7 0 to 65,535 0 to 65, 534 0 to 65,532

L LB LW LD

0.0 to 65,535.7 0 to 65,535 0 to 65, 534 0 to 65,532

Data bit Data byte Data word Data double word Data block opened with the statement “OPN DI”: Data bit Data byte Data word Data double word Local data

Temporary local data bit Temporary local data byte Temporary local data word Temporary local data double word

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-9

Structure and Components of Instructions and Statements

2.2

Meaning of the CPU Register in Statements

Accumulators

The two 32-bit accumulators are general purpose registers that you use to process bytes, words, and double words. You can load constants or values from the memory as addresses into the accumulator and perform logic operations on them. You can also transfer the result of an operation from accumulator 1 to a memory location. Figure 2-4 identifies the areas of an accumulator. The stack mechanism for accumulator administration is as follows:


A load instruction always acts on accumulator 1 and saves the old contents to accumulator 2.


A transfer instruction does not change the accumulators (with the exception of instructions TAR1 and TAR2).


The TAK instruction swaps the contents of accumulators 1 and 2. For information on accumulator administration for math instructions, see Section 9.1.

31

24 High byte

23

16 Low byte

High word Figure 2-4

15

8 7 High byte

Accumulator (1 or 2)

0 Low byte

Low word

Areas of an Accumulator

Nesting Stack

The nesting stack is a storage area that is one byte wide. This storage area is used by the nesting instructions A(, O(, X(, AN(, ON(, XN(. These instructions save the current result of logic operation (RLO) to the nesting stack and start a new logic string. The nesting stack can accommodate seven entries. A nesting stack entry consists of the RLO, BR, and OR bits of the status word, and a function code to indicate which of the Boolean logic operations is to be used (A, AN, O, ON, X, or XN). The “)” instruction closes a nesting expression by performing the following functions:


Fetches an entry from the nesting stack
Restores the OR and BR bits
Defines the new RLO by logically combining the current RLO (that is, the RLO from the expression nested in parentheses) with the RLO of the stack entry according to the function code (see Section 5.4)

2-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Figure 2-5 shows the structure of an entry in the nesting stack. Below Figure 2-5 you can see an explanation of the bits in the nesting stack byte.

Figure 2-5

27

26

0

0

25

24

23

22

21

20

BR

RLO

OR Function code

Structure of an Entry in the Nesting Stack

The nesting stack byte contains the following bits (see Figure 2-5):


Non-assigned bits (bits 7 and 6 with signal state “0”)
The stored binary result (BR)
The stored result of logic operation (RLO)
The stored OR bit in the functions A( and AN( Zero is stored in all other functions


The function code (in bits 2, 1 and 0) Function code With the help of the function code, the instruction “)” defines the function which is to be used for the combination of the current RLO (that is the RLO from the expression nested in parentheses) with the RLO of the nesting stack entry. Table 2-12 shows the bit combinations of the function code for each function type: Table 2-12

Function Codes of Nesting Stack Byte

Instruction

Function Code 2

Function Code 1

Function Code 0

A(

0

0

0

AN(

0

0

1

O(

0

1

0

ON(

0

1

1

X(

1

0

0

XN(

1

0

1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-11

Structure and Components of Instructions and Statements

Nesting Stack with Entries and Pointer The nesting stack and the nesting stack pointer must be stored either in the interrupt stack or they must be fetched from it, when the batches change. The number in the nesting stack pointer indicates the number of entries available in the nesting stack (see Figure 2-6). 15

7 Nesting stack entry 7

Nesting stack entry 6

Nesting stack entry 5

Nesting stack entry 4

Nesting stack entry 3

Nesting stack entry 2

Nesting stack entry 1

Nesting stack pointer

Figure 2-6

Status Word

Rising addresses

Structure of a Nesting Stack with Entries and Pointer

The status word contains bits that you can reference in the address of bit logic and word logic instructions. Figure 2-7 shows the structure of the status word. The sections that follow the figure explain the significance of bits 0 through 8. 215...

Figure 2-7

First Check

0

...29

28

27

26

BR

CC 1 CC 0

25 OV

24 OS

23

22

OR

STA

21 RLO

20 FC

Structure of the Status Word

Bit 0 of the status word is called the first-check bit (FC bit, see Figure 2-8). The signal state of 0 in the FC bit indicates that, following this point in your program, the next logic instruction begins a new logic string. (The bar over the FC indicates that it is negated.) Each logic instruction checks the signal state of the FC bit as well as the signal state of the location it addresses. If the FC bit is 0, the instruction stores the result of the signal state check in the result of logic operation bit of the status word (RLO bit, see next section) and sets the FC bit to 1. This process is called a first check (see Figure 2-8 and Section 5.6). If the signal state of the FC bit is equal to 1, an instruction combines the result of its signal state check on the contact it addresses with the value stored in the previous RLO bit (see Figure 2-8). A string of logic instructions always ends with an output instruction (S, R, or =, see Sections 5.7 and 5.8), a jump instruction related to the result of logic operation (JC, see Section 16), or one of the nesting instructions A(, O(, X(, AN(, ON(, or XN( (see Section 5.4). Such an output, jump instruction, or nesting instruction resets the FC bit to 0 (see Figure 2-8).

2-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Result of Logic Operation

Bit 1 of the status word is called the RLO bit (RLO stands for “result of logic operation,” see Figure 2-7). This bit stores the result of a bit logic instruction or math comparison. For example, the second instruction in a string of bit logic instructions checks the signal state of a contact and produces a result of 1 or 0. Then the instruction combines this result with the value stored in the RLO bit of the status word according to the principles of Boolean logic (see First Check above and Chapter 5). The result of this logic operation is stored in the RLO bit of the status word, replacing the former value in the RLO bit. Each subsequent instruction in the string performs a logic operation on two values: the result produced when the instruction checks the contact, and the current RLO. You can set the RLO to 1 unconditionally by using the SET instruction; you can reset the RLO to 0 unconditionally by using the CLR instruction. You can use a Boolean bit logic instruction on a first check to assign the state of the contents of a Boolean bit memory location to the RLO. You can use the RLO to trigger jump instructions.

Statement List Program

Signal State Result of Check of Input (I) or Output (Q)

RLO Bit

FC Bit

Explanation

0

FC bit = 0 indicates that next instruction begins logic string

A I 1.0

1

1

1

1

Result of first check is stored in RLO bit. FC bit is set to 1.

AN I 1.1

0

1

1

1

Result of check is combined with previous RLO according to AND truth table. FC bit remains 1.

= Q 4.0

1

0

RLO is assigned to output coil. FC bit is reset to 0.

Figure 2-8

Status Bit

Effect of Signal State of FC Bit on Logic Instructions

The status bit (STA bit) stores the value of a bit that is referenced. The status of a bit instruction that has read access to the memory (A, AN, O, ON, X, XN) is always the same as the value of the bit that this instruction checks (the bit on which it performs its logic operation). The status of a bit instruction that has write access to the memory (S, R, =) is the same as the value of the bit to which the instruction writes or, if no writing takes place, the same as the value of the bit that the instruction references. The status bit has no significance for bit instructions that do not access the memory. Such instructions set the status bit to 1 (STA=1). The status bit is not checked by an instruction. It is interpreted during program test (program status) only.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

2-13

Structure and Components of Instructions and Statements

OR Bit

The OR bit is needed if you use the O instruction to perform a logical AND before OR operation. An AND function may contain the following instructions: A, AN A(, AN(, ), and NOT. The OR bit shows these instructions that a previously executed AND function has supplied the value 1, thus forestalling the result of the logical OR operation. Any other bit-processing command resets the OR bit (see Section 5.4).

Overflow Bit

The overflow bit (OV bit) indicates a fault. It is set by a math instruction or a floating-point comparison instruction after a fault occurs (overflow, illegal operation, illegal floating-point number). This bit is set according to the result of the next math instruction or comparison instruction.

Stored Overflow Bit

The stored overflow bit (OS bit) is set together with the OV bit when a fault occurs. Because the OS bit remains set after the fault has been eliminated, it stores the OV bit status and indicates whether or not a fault occurred in one of the previously executed instructions. The following commands reset the OS bit: JOS (jump after stored overflow), the block call commands, and the block end commands.

Condition Code 1 and Condition Code 0

The CC 1 and CC 0 bits (condition codes) provide information on the following results or bits:


Result of a math operation
Result of a comparison
Result of a digital operation
Bits that have been shifted out by a shift or rotate command Tables 2-13 through 2-18 list the significance of CC 1 and CC 0 after your program executes certain instructions. Table 2-13

CC 1 and CC 0 after Math Instructions, without Overflow

CC 1

CC 0

Explanation

0

0

Result = 0

0

1

Result < 0

1

0

Result > 0

Table 2-14

2-14

CC 1 and CC 0 after Integer Math Instructions, with Overflow

CC 1

CC 0

Explanation

0

0

Negative range overflow in +I and +D

0

1

Negative range overflow in I and D Positive range overflow in +I, –I, +D, –D, NEGI, and NEGD

1

0

Positive range overflow in I, D, /I, and /D Negative range overflow in +I, –I, +D, and –D

1

1

Division by 0 in /I, /D, and MOD

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Structure and Components of Instructions and Statements

Table 2-15

CC 1 and CC 0 after Floating-Point Math Instructions, with Overflow

CC 1

CC 0

0

0

Gradual underflow

0

1

Negative range overflow

1

0

Positive range overflow

1

1

Invalid floating-point number

Table 2-16

Explanation

CC 1 and CC 0 after Comparison Instructions

CC 1

CC 0

0

0

Accumulator 2 = accumulator 1

0

1

Accumulator 2 < accumulator 1

1

0

Accumulator 2 > accumulator 1

1

1

Accumulator 1 or accumulator 2 is an invalid floating-point number

Table 2-17

Explanation

CC 1 and CC 0 after Shift and Rotate Instructions

CC 1

CC 0

0

0

Last bit shifted out = 0

1

0

Last bit shifted out = 1

Table 2-18

Explanation

CC 1 and CC 0 after Word Logic Instructions

CC 1

CC 0

0

0

Result = 0

1

0

Result <> 0

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Explanation

2-15

Structure and Components of Instructions and Statements

Binary Result Bit

The binary result bit (BR bit) forms a link between the processing of bits and words. It is an efficient means of interpreting the result of a word operation as a binary result and integrates this result in a binary logic string. Viewed in this way, the BR bit represents a machine-internal memory bit to which the RLO is saved prior to a word operation that changes the RLO, so that the RLO will be available again after the operation to continue the interrupted bit string. For example, the BR bit makes it possible for you to write a function block (FB) or a function (FC) in statement list (STL) and then call the FB or FC from ladder logic (LAD, see the Reference Manual /233/). When writing a function block or function that you want to call from LAD, no matter whether you write the FB or FC in STL or LAD, you are responsible for managing the BR bit. The BR bit corresponds to the enable output (ENO) of a LAD box. You should use the SAVE instruction (in STL, see Section 5.9) or the –––(SAVE) coil (in LAD) to store an RLO in the BR bit according to the following criteria:


Store an RLO of 1 in the BR bit for a case where the FB or FC is executed without error.


Store an RLO of 0 in the BR bit for a case where the FB or FC is executed with error You should program these instructions at the end of the FB or FC so that these are the last instructions that are executed in the block. When you call a system function block (SFB) or a system function (SFC) in your program, the SFB or SFC indicates whether the CPU was able to execute the function with or without errors by providing the following information in the binary result bit:


If an error occurred during execution, the BR bit is 0.
If the function was executed with no error, the BR bit is 1.

2-16

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3

Addressing Chapter Overview

Section

Description

Page

3.1

Immediate Addressing

3-2

3.2

Direct Addressing

3-2

3.3

Memory Indirect Addressing

3-3

3.4

Address Registers

3-6

3.5

Area-Internal Register Indirect Addressing

3-7

3.6

Area-Crossing Register Indirect Addressing

3-11

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-1

Addressing

3.1

Immediate Addressing

Description

With immediate addressing, the address is coded directly in the instruction; that is, it directly follows the value with which the instruction is to work (for example, Load). An instruction can also provide its own value (for example, SET, see Table 3-1). Table 3-1

Examples

3.2

Immediate Addressing Description

Example SET

Set the RLO to 1.

OW W#16#A320

Or Word.

L 27

Load the integer value 27 into accumulator 1.

L ’ABCD’

Load the ASCII characters ABCD into accumulator 1.

L B#(100,12)

Load the two bytes 100 and 12 into accumulator 1.

L C#0100

Load the BCD value 0000 into accumulator 1.

Direct Addressing

Description

An instruction that uses direct addressing has the following two-part address that indicates the location of the value that the instruction is going to process:


An address identifier (for example, “IB” for “input byte”)
An exact location within the memory area that is indicated by the address identifier The address points directly to the location of the value. Table 3-2

Examples

3-2

Direct Addressing Example

Description

A I 0.0

Perform an AND logic operation on input bit I 0.0.

S L 20.0

Set the local data bit L 20.0.

= M 115.4

Assign the RLO to memory bit M 115.4

L IB0

Load input byte IB0 into accumulator 1.

L MW64

Load memory word MW64 into accumulator 1.

T DBD12

Transfer the contents from accumulator 1 into data double word DBD12.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

3.3

Memory Indirect Addressing

Description

An instruction that uses memory indirect addressing has the following two-part address that indicates the location of the value that the instruction is going to process:


An address identifier (for example, “IB” for “input byte”)
One of the following pointers: – A word that contains the number of a timer (T), counter (C), data block (DB), function (FC), or function block (FB) – A double word that contains the exact location of a value within the memory area that is indicated by the address identifier The address indicates the location of the value or number indirectly via the pointer. This word or double word can be in one of the following areas:


Bit memory (M)
Data block (DB)
Instance data block (DI)
Local data (L) The advantage of memory indirect addressing is that you can modify the statement address dynamically during program execution.

Using the Right Syntax

When working with a memory indirect address that is stored in the data block area of memory, first you must open the data block by using the Open a Data Block (OPN) instruction. Then you can use the data word or data double word as an indirect address, as shown in the following example: OPN DB10 L IB [DBD20]

Examples Table 3-3 Memory Indirect Addressing

Example

Description

A I [MD2] or A I [anna]

Perform an And logic operation on the input bit whose exact location is in memory double word MD2 or in the location designated by “anna” in the symbol table, as a reference to MD2.

= DIX [DBD2]

Assign the RLO bit to the instance data bit whose exact location is in data double word DBD2.

OPN DB [LW2]

Open the data block whose data block number is located in local word LW2.

O Q [LD3] or O Q [boxcar]

Perform an Or logic operation on the output bit that is located in a local data double word LD3 or in a local TEMP variable designated as “boxcar.”

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-3

Addressing

Pointer Format

There are two possible pointer formats: word and double word. The abbreviation for a pointer in word format ends in W (for example, DBW). Figure 3-1 shows the pointer format for a word. The abbreviation for a double word format ends in D (for example, DBD). Figure 3-2 shows the pointer format for a double word.

15.. ..8 nnnn nnnn

7.. ..0 nnnn nnnn

Bits 0 to 15 (nnnn nnnn nnnn nnnn): number (range 0 to 65,535) of a timer (T), counter (C), data block (DB), function (FC), or function block (FB)

Figure 3-1

Word Pointer Format for Memory Indirect Addressing

The following two examples show how to work with the word pointer format:

STL

Explanation

L +5 T MW2 OPN DB[MW2]

Load the value 5 as an integer into accumulator 1. Transfer the contents of accumulator 1 to memory word MW2. Open data block 5.

STL

Explanation

OPN L T A

3-4

DB10 +20 DBW10 T[DBW10]

Open data block DB10. Load the value 20 as an integer into accumulator 1. Transfer the contents of accumulator 1 to data word DBW10 Check the signal state of timer T 20.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

31.. ..24 23.. ..16 15.. ..8 0000 0000 0000 0 bbb bbbb bbbb

7.. bbbb b

..0 xxx

Bits 3 to 18 (bbbb bbbb bbbb bbbb): byte number (range 0 to 65,535) of the addressed byte Bits 0 to 2 (xxx): bit number (range 0 to 7) of the addressed bit

Figure 3-2

Double Word Pointer Format for Memory Indirect Addressing

Note If you access a byte, word, or double word, be sure that the bit number of your pointer is 0.

The following two examples show you how to work with the double word pointer format:

STL

Explanation

L

P#8.7

T

MD2

Load 2#0000 0000 0000 0000 0000 0000 0100 0111 (binary value) into accumulator 1. Store the exact location 8.7 in memory double word MD2.

A I [MD2] = Q [MD2]

The controller checks input bit I 8.7 and assigns its signal state to output bit Q 8.7.

STL

Explanation

L

P#8.0

T

MD2

L IB [MD2] T MW [MD2]

Load 2#0000 0000 0000 0000 0000 0000 0100 0000 (binary value) into accumulator 1. Store the exact location 8 in memory double word MD2. The controller loads input byte IB8 and transfers the contents to memory word MW8. The exact location 8 comes from memory double word MD2.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-5

Addressing

3.4

Address Registers

Explanation

Some types of indirect addressing in statement list programming require the use of certain registers in the CPU. These registers are described below.

Address Registers 1 and 2

Address registers 1 and 2 (AR1 and AR2) are 32-bit registers that accept an area-internal or area-crossing pointer for commands that use register-indirect addressing (see Sections 3.5 and 3.6).

Pointers

Pointers are used in register-indirect addressing (see Sections 3.5 and 3.6). The following two types are available:


Area-internal: used for area-internal access to bits, bytes, words, and double words in memory areas P, I, Q, M, DBX, DIX, and L


Area-crossing: used for area-crossing access to bits, bytes, words, and double words in memory areas P, I, Q, M, DBX, DIX, and L

3-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

3.5

Area-Internal Register Indirect Addressing

Description

An instruction that uses area-internal register indirect addressing has the following two-part address that indicates the memory location of the value that the instruction is going to process:


An address identifier (for example, “LD” for “local data double word,” see Table 2-6)


An address register and a pointer to specify byte and bit. The byte and bit indicate an offset, which, when added to the contents of the register, indicate the memory location of the value that the instruction is to process. The address points to the memory location of the value indirectly via the address register plus offset. A statement that uses area-internal register indirect addressing does not change the value in the address register.

Calculating the Memory Location of the Address

The address of an instruction points to the value that the instruction is going to process. Where area-internal register indirect addressing is concerned, the address points to the memory location of the value indirectly via the address register plus offset. Figure 3-3 shows how you calculate the memory location for the address of the Assign (=) instruction in the following statement: = Q [AR1, P#1.1]

Byte

+

Bit

Contents of address register AR1: 8.7

byte 8, bit 7

Offset P#:

byte 1, bit 1

1.1

Memory location:

output byte Q 10.0

bytes: 9, bits: 8 (= 1 byte) (9 bytes + 1 byte = 10 bytes)

Figure 3-3

Calculating the Memory Location of Output Q [AR1, P#1.1]

You calculate the memory location of the address by adding the byte portion of the contents of the address register to the byte portion of the offset pointer and by adding the bit portion of the contents of the address register to the bit portion of the offset pointer. You calculate the byte portion of the memory location using decimal math and the bit portion using octal math (8 bits = 1 byte). There can be a carry between the bit and byte portions.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-7

Addressing

Table 3-4

Examples

Area-Internal Register Indirect Addressing Example

Description

A I [AR1, P#4.3]

Perform an And logic operation on the input bit whose memory location is calculated by the contents of address register AR1 plus 4 bytes, plus 3 bits.

= DIX [AR2, P#0.0]

Assign the RLO bit to the instance data bit whose memory location is in address register AR2.

L IB [AR1, P#100.0]

Load the input byte whose memory location is calculated by the contents of address register AR1 plus 100 bytes into accumulator 1.

T LD [AR2, P#56.0]

Transfer the contents of accumulator 1 into local data double word LD whose memory location is calculated by the contents of address register AR2 plus 56 bytes. With reference to addressing local data, please read the Warning below.

!

Warning Possible overwriting of the data that is used by the compiler. When you use absolute addressing to access temporary local data, there is no guarantee that there will be no conflict between the data used by the compiler and the local data that you are attempting to access by means of absolute addressing. It is possible that you overwrite some of the data that the compiler uses. (For example, the compiler uses local data for transferring formal parameters.) Local data that the compiler needs are attached to the symbolic data that are defined by the person doing the programming. When accessing temporary local data, you are advised to choose symbolic addressing over absolute addressing.

3-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

Pointer Format

Area-internal register indirect addressing has only one possible pointer format: double word. This double word contains an address encoded as a bit address. The abbreviation for a double word format ends in D (for example, DBD). Figure 3-4 shows the pointer format for a double word.

31.. ..24 23.. ..16 15.. ..8 7.. 0000 0000 0000 0 bbb bbbb bbbb bbbb b

..0 xxx

Bit 31 = 0 to indicate area-internal register indirect addressing Bits 3 to 18 (bbbb bbbb bbbb bbbb): byte number (range 0 to 65,535) of the addressed bit Bits 0 to 2 (xxx): bit number (range 0 to 7) of the addressed bit Figure 3-4

Double Word Pointer Format for Area-Internal Register Indirect Addressing

Note If you access a byte, word, or double word, be sure that the bit number of your pointer is 0.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-9

Addressing

The following two examples show you how to work with the double word pointer format:

STL L

Explanation P#8.7

Load a double word pointer to bit address location 8.7 into accumulator 1.

LAR1

Store a double word pointer to bit address location 8.7 in address register AR1.

A I [AR1, P#0.0]

The CPU adds the offset (P#0.0) to the contents of address register AR1 (8.7) and uses this address as the location of an And bit logic instruction. The contents of AR1 remain unchanged.

= Q [AR1, P#1.1]

The CPU assigns the result of the And bit logic operation (RLO) to an address (Q 10.0). The CPU calculates this address by adding the contents of address register AR1 (8.7) and the offset (P#1.1).

STL

Explanation

L

P#8.0

Load a double word pointer to bit address location 8.0 into accumulator 1.

LAR2

Store a double word pointer to bit address location 8.0 in address register AR2.

L IB [AR2, P#2.0]

The CPU loads input byte IB10 into accumulator 1.

T MW [AR2, P#200.0]

The CPU transfers the contents of accumulator 1 to memory word MW208. The location 208 comes from 8 (AR2) plus 200 (offset), which is 208.

3-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

3.6

Area-Crossing Register Indirect Addressing

Description

An instruction that uses area-crossing register indirect addressing has the following two-part address that indicates the memory location of the value that the instruction is going to process:


An address identifier that indicates the size of a data object (for example, “B” for “byte,” see Table 2-8). The memory area is indicated in bits 24, 25, and 26 of the address register.


An address register and a pointer that indicate an offset which, when added to the contents of the address register, indicates the memory location of the value that is to be processed by the instruction. The pointer is indicated by P#byte.bit. The address points to the memory location of the value indirectly via the address register plus offset. A statement that uses area-crossing register indirect addressing does not change the value in the address register.

Calculating the Memory Location of the Address

The address of an instruction points to the value that the instruction is going to process. Where area-crossing register indirect addressing is concerned, the address points to the memory location of the value indirectly via the address register plus offset. Figure 3-5 shows how you calculate the memory location for the address of the Assign (=) instruction in the following statement: = [AR1, P#1.1]

Byte

+

Bit

Contents of address register AR1: 8.7

byte 8, bit 7

Offset P#:

byte 1, bit 1

1.1

Memory location:

byte 10.0

bytes: 9, bits: 8 (= 1 byte) (9 bytes + 1 byte = 10 bytes)

Figure 3-5

Calculating the Address [AR1, P#1.1]

You calculate the memory location of the address by adding the byte portion of the contents of the address register to the byte portion of the offset pointer and by adding the bit portion of the contents of the address register to the bit portion of the offset pointer. You calculate the byte portion of the memory location using decimal math and the bit portion using octal math (8 bits = 1 byte). There can be a carry between the bit and byte portions.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-11

Addressing

Example

Table 3-5 provides examples of area-crossing register indirect addressing. The address must contain an additional area identification in bits 24, 25, and 26 of the pointer. The addressed information is in the address register. Table 3-5

Area-Crossing Register Indirect Addressing Description

Example A [AR1, P#4.3]

Perform an And logic operation on the bit whose memory location is calculated by the contents of address register AR1, plus 4 bytes plus 3 bits. The memory area of the bit is indicated in bits 24, 25, and 26 of address register AR1.

= [AR2, P#0.0]

Assign the RLO bit to the bit whose memory location is in address register AR2. The memory area of the bit is indicated in bits 24, 25, and 26 of address register AR2.

L B [AR1, P#100.0]

Load into accumulator 1 the byte whose memory location is calculated in address register AR1 plus 100 bytes. The memory area of the byte is indicated in bits 24, 25, and 26 of address register AR1.

T D [AR2, P#56.0]

Transfer the contents of accumulator 1 into the double word whose memory location is calculated by the contents of address register AR2 plus 56 bytes. The memory area of the double word is indicated in bits 24, 25, and 26 of address register AR2.

Table 3-6 lists the binary code in bits 24, 25, and 26 of the pointer that identifies the area. Table 3-6

Area Identification for Area-Crossing Register Indirect Addressing

Area Identification (Memory Area)

Binary Contents of Bits 26, 25, and 24

P

(I/O, external inputs and outputs)

000

I

(process-image input)

001

Q

(process-image output)

010

M

(bit memory)

011

DBX (data block)

100

DIX (data block)

101

(previous local data, that is, the local data of the previous incompleted block)

3-12

111

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Addressing

Pointer Format

Area-crossing register indirect addressing has only one possible pointer format: double word. The abbreviation for a double word format ends in D (for example, DBD). Figure 3-6 shows the pointer format for a double word.

31.. ..24 23.. 1000 0rrr 0000 0

..8 7.. 3.. ..16 15.. ..0 bbb bbbb bbbb bbbb b xxx

Bit 31 = 1 to indicate area-crossing register indirect addressing Bits 24, 25, and 26 (rrr): area identification (memory area, see Table 3-6) Bits 3 to 18 (bbbb bbbb bbbb bbbb): byte number (range 0 to 65,535) of the addressed bit Bits 0 to 2 (xxx): bit number (range 0 to 7) of the addressed bit Figure 3-6

Double Word Pointer Format for Area-Crossing Register Indirect Addressing

Note If you access a byte, word, or double word, be sure that the bit number of your pointer is 0. You cannot access local data using area-crossing register indirect addressing!

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

3-13

Addressing

The following two examples show you how to work with the double word pointer format:

STL L

Explanation P#I 8.7

Load a double word pointer to bit address location I 8.7 into accumulator 1.

LAR1

Store a double word pointer to bit address location I 8.7 in address register AR1.

L P#Q 8.7

Load a double word pointer to bit address location Q 8.7 into accumulator 1.

LAR2

Store a double word pointer to bit address location Q 8.7 in address register AR2.

A [AR1, P#0.0]

The CPU adds the contents of address register AR1 (P#I 8.7) and the offset (P#0.0) and uses the address pointed to by the result (I 8.7) as the address of an And bit logic instruction. The contents of AR1 remain unchanged.

= [AR2, P#1.1]

STL L

The CPU assigns the result of the And bit logic operation (RLO) to an address (Q 10.0). The CPU calculates this address by adding the contents of address register AR2 (P#Q 8.7) and the offset (P#1.1) and dereferencing the pointer. The contents of AR2 remain unchanged.

Explanation P#I 8.0

Load a double word pointer to bit address location I 8.0 into accumulator 1.

LAR2

Store a double word pointer to bit address location I 8.0 in address register AR2.

L P#M 8.0

Load a double word pointer to bit address location M 8.0 into accumulator 1.

LAR1

Store a double word pointer to bit address location M 8.0 in address register AR1.

L B [AR2, P#2.0]

The CPU loads input byte IB10.

T W [AR1, P#200.0]

The CPU transfers the contents to memory word MW208. Input byte 10 comes from 8 (AR2) plus 2 (offset). Memory word 208 comes from 8 (AR1) plus 200 (offset), which is 208.

3-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Accumulator Operations and Address Register Instructions

4

Chapter Overview

Page

Section

Description

4.1

Overview

4-2

4.2

ENT and LEAVE

4-3

4.3

Incrementing and Decrementing

4-6

4.4

+AR1 und +AR2: Adding a Constant to Address Register 1 or Address Register 2

4-7

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

4-1

Accumulator Operations

4.1

Overview The following instructions are available to you for handling the contents of one or both accumulators: Mnemonic

Instruction

Explanation

TAK

Toggle Accumulator 1 with Accumulator 2

This instruction exchanges the contents of accumulator 1 with the contents of accumulator 2.

PUSH with 2 ACCUs

Accumulator 1 to Accumulator 2 This instruction copies the contents of accumulator 1 to accumulator 2.

POP with 2 ACCUs

Accumulator 2 to Accumulator 1 This instruction copies the contents of accumulator 2 to accumulator 1.

PUSH with 4 ACCUs

Copy ACCU 3 to ACCU 4, ACCU 2 to ACCU 3, ACCU 1 to ACCU 2

This instruction copies the contents of accumulator 3 to accumulator 4, the contents of accumulator 2 to accumulator 3 and the contents of accumulator 1 to accumulator 2.

POP with 4 ACCUs

Copy ACCU 2 to ACCU 1, ACCU 3 to ACCU 2, ACCU 4 to ACCU 3

This instruction copies the contents of accumulator 2 to accumulator 1, the contents of accumulator 3 to accumulator 2 and the contents of accumulator 4 to accumulator 3.

ENT

Enter accumulator stack

This instruction copies the contents of accumulator 3 to accumulator 4 and the contents of accumulator 2 to accumulator 3.

LEAVE

Leave accumulator stack

This instruction copies the contents of accumulator 3 to accumulator 2 and the contents of accumulator 4 to accumulator 3.

INC

Increment Accumulator 1

This instruction increases the contents of the low byte of the low word of accumulator 1 by the 8-bit constant that is indicated in the instruction statement. The constant can be in the range of 0 to 255.

DEC

Decrement Accumulator 1

This instruction decreases the contents of the low byte of the low word of accumulator 1 by the 8-bit constant that is indicated in the instruction statement. The constant can be in the range of 0 to 255.

+AR1, +AR2

Add Accumulator 1 to Address Register

This instruction adds the contents of the low word of accumulator 1 to address register 1 or 2.

+AR1 P#Byte.Bit, +AR2 P#Byte.Bit

Add Constant to Address Register

This instruction adds a constant to the contents of address register 1 or 2.

BLD

Program Display Instruction

”This instruction does not carry out any function and does not influence the status bits. The instruction is only relevant to the programming device (PG) when a program is displayed. The address is the ID of the instruction BLD and is generated by the programming device.”

NOP 0

Null Instruction 0

NOP 1

Null Instruction 1

”These instructions do not carry out any function, nor do they influence the contents of the status word. The instructions NOP 1 and NOP 0 are required for decompiling. The instruction code contains a bit pattern with either 16 zeroes or 16 ones.”

For information on reversing the order of bytes in accumulator 1, see Section 12.3.

4-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Accumulator Operations

4.2

ENT and LEAVE

Description

With the instructions ENT (Enter Accumulator Stack) and LEAVE (Leave Accumulator Stack) you can carry out the following functions:


The instruction ENT copies the contents of Accumulator 3 to Accumulator 4 and the contents of Accumulator 2 to Accumulator 3. If you program the ENT instruction directly before a load instruction, it SHIFTS Accumulator 2 and Accumulator 3 further in the stack.


The instruction LEAVE copies the contents of Accumulator 3 to Accumulator 2 and the contents of Accumulator 4 to Accumulator 3. If you program the LEAVE instruction directly before a shift and rotate instruction, which combines accumulators, then the LEAVE instruction will function like a math operation.

ENT

Figure 4-1 shows how the ENT instruction works.

ENT

ACCU 4 31

0 I

II

III

ACCU 4 31

IV

0 V

ACCU 3 0 VI

VII

0 IX

ACCU 2 XI

Figure 4-1

XII

0 IX

ACCU 1

X

XI

XII

ACCU 1 0

XIV

XI

31

XII

31 XIII

X

ACCU 2 0

X

VIII

31

VIII

31 IX

VII

ACCU 3

31 V

VI

XV

XVI

31 XIII

0 XIV

XV

XVI

Copying the contents of Accumulator 3 to Accumulator 4 and the contents of Accumulator 2 to Accumulator 3 in the ENT instruction ENT

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

4-3

Accumulator Operations

LEAVE

Figure 4-2 shows how the LEAVE instruction works.

ACCU 4

31

0 I

II

ACCU 4

LEAVE

31 III

0 I

IV

ACCU 3 0 VI

VII

0 I

VIII

XI

XII

V

ACCU 1

Figure 4-2

Example

IV

0 VI

VII

VIII

XV

XVI

ACCU 1

31

0 XIV

III

31

0

XIII

II

ACCU 2

31 X

IV

31

ACCU 2 IX

III

ACCU 3

31 V

II

XV

31

XVI

XIII

0 XIV

Copying the contents of Accumulator 3 to Accumulator 2 and the contents of Accumulator 4 to Accumulator 3 in the LEAVE instruction

The following program extract shows the use of the ENT instruction. The floating points in the data double words DBD0 and DBD4 should be added together. The sum should then be divided by the difference of the floating points of the data double words DBD8 and DBD12.

DBD16 =

DBD0 + DBD4 DBD8 – DBD12

The quotient of the above division should be stored in DBD16. In this example, the purpose of the ENT instruction is to take the interim result (DBD0+DBD4), which is located in Accumulator 2 and save it in Accumulator 3. The subtraction command (-R) copies the interim result back to Accumulator 2 following the subtraction.

4-4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Accumulator Operations

STL

Explanation

L

DBD0

L

DBD4

+R

L

DBD8

ENT L

DBD12

–R

/R T

DBD16

Load the value from data double word DBD0 in ACCU1 (the value must be in floating-point format). Copy the value from ACCU1 to ACCU2.Load the value from data double word DBD4 in ACCU1 (the value must be in floating-point format). Add the contents of ACCU1 and ACCU2 as floating-point numbers (32 bits, IEEE-FP) and store the result in ACCU1. Copy the value from ACCU1 to ACCU2. Load the value from data double word DBD8 to ACCU1. Copy the contents of ACCU3 to ACCU4. Copy the contents of ACCU2 (interim result) to ACCU3. Copy the contents of ACCU1 to ACCU2. Load the contents from data double word DBD12 to ACCU1. Subtract the contents of ACCU1 from the contents of ACCU2. Store the result in ACCU1. Copy the contents of ACCU3 to ACCU2. Divide the contents of ACCU 2 by the contents of ACCU1. Save the quotient in ACCU1. Transfer the result (ACCU1) to the data double word DBD16.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

4-5

Accumulator Operations

4.3

Incrementing and Decrementing

Description

You can use the Increment Accumulator 1 (INC) and Decrement Accumulator 1 (DEC) instructions to perform the following functions:


INC increases the contents of the low byte of the low word of accumulator 1 by the 8-bit constant that is indicated in the instruction statement. The constant can be in the range of 0 to 255.


DEC decreases the contents of the low byte of the low word of accumulator 1 by the 8-bit constant that is indicated in the instruction statement. The constant can be in the range of 0 to 255. The CPU always executes the INC and DEC instructions, regardless of the result of logic operation. These instructions do not affect the RLO nor do they change any of the bits in the status word. Note These instructions are not suitable for 16-bit or 32-bit math because no carry is made from the low byte of the low word of accumulator 1 to the high byte of the low word of accumulator 1. For 16-bit or 32-bit math, use the +I or +D instruction, respectively.

Example

The following sample program provides an example of how the INC instruction works within a loop triggered by a conditional jump.

STL

Explanation

Body of a loop operation

M1:

4-6

L T L INC T . . L <= SPB

1 MB10 MB10 1 MB10

B#16#5 I M1

Set the loop counter to 1. Load the contents of memory byte MB10 into accumulator 1. Increment the loop counter by 1. Transfer the contents of accumulator 1 to memory byte MB10. Instruction section which is processed five times. If the program has not run through the loop five times, then return to LOOP.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Accumulator Operations

4.4

+AR1 und +AR2: Adding a Constant to Address Register 1 or Address Register 2

Description

Using the instructions +AR1 and +AR2 you can add a constant to the contents of address registers 1 and 2: Table 4-1

Adding to the Contents of Address Registers

Instruction

1

Address

Function

+AR1

–

Adds the contents of the low word of accumulator 1 to the contents of address register 1.

+AR2

–

Adds the contents of the low word of accumulator 1 to the contents of address register 2.

+AR1

P#Byte.Bit: (range 0.0 to 4095.7)1

Adds a pointer constant to the contents of address register 1.

+AR2

P#Byte.Bit: (range 0.0 to 4095.7)1

Adds a pointer constant to the contents of address register 2.

The bits 24, 25, and 26 of the address register remain unchanged. These bits indicate the memory area.

Note The address register 2 is used when multiple instances are being processed. Therefore, before programming the command “+AR2”, you must “save” the contents of AR2 and load them again later.

Examples

Below are sample statements that use the +AR1 and +AR2 instructions. Loading the pointer format into accumulator 1 and then using the +AR1 or +AR2 instruction, as shown in the first two statements below, enables you to select from a range of 0.0 to 8191.7.

STL

Explanation

L P#250.7 +AR1

Load a Add the address Because

TAR2 #SAVE_AR2 +AR2 P#126.7 . . L AR2 #SAVE_AR2

pointer constant (250.7) into accumulator 1. contents of accumulator 1 (250.7) to the contents of register 1. multiple instances are using AR2 as base.

Add a pointer constant (126.7) to the contents of address register 2. Restore AR2.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

4-7

Accumulator Operations

4-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5

Bit Logic Instructions Chapter Overview

Section

Description

Page

5.1

Boolean Bit Logic

5-2

5.2

Bit Logic Instructions and Relay Coil Circuit

5-6

5.3

Evaluating Conditions Using And, Or, and Exclusive Or

5-10

5.4

Nesting Expressions and And before Or

5-14

5.5

Instructions for Transitional Contacts: FP, FN

5-16

5.6

Output of Boolean Logic String

5-20

5.7

Set and Reset Instructions: S and R

5-21

5.8

Assign Instruction (=)

5-24

5.9

Negating, Setting, Clearing, and Saving the RLO

5-26

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-1

Bit Logic Instructions

5.1

Boolean Bit Logic

Explanation

Boolean bit logic applies to the following basic instructions:


And (A) and its negated form, And Not (AN)
Or (O) and its negated form, Or Not (ON)
Exclusive Or (X) and its negated form, Exclusive Or Not (XN) These instructions perform the following basic functions:


They check the signal state of an address to establish whether an address is activated “1”, or not activated “0”.


They check the signal state of a timer or a counter to establish whether it is set at “0” (value = 0) or “1” (value > 0). The FC bit determines the result of logic operation (RLO):


If FC is 0, the result of the state check will remain unchanged and will be stored in the RLO (start of a logic string).


If FC is 1, the result of the state check will be combined with the logic instruction (A, O, X) according to the truth table and will be stored in the RLO.

Truth Table at the Start of a Boolean Logic String

The result of logic operation can be determined with the help of the following truth table: Instruction

Status of Address

Result in RLO

And

0 1

0 1

And Not

0 1

1 0

Or

0 1

0 1

Or Not

0 1

1 0

Exclusive Or

0 1

0 1

Exclusive Or Not

0 1

1 0

Mnemonic A AN O ON X XN

5-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Truth Table within the Boolean Logic String

After the second Boolean bit operation the RLO can be established with the help of the following table: Instruction

RLO Before Instruction

Status of Address

Result in RLO

And

0 0 1 1

0 1 0 1

0 0 0 1

And Not

0 0 1 1

0 1 0 1

0 0 1 0

Or

0 0 1 1

0 1 0 1

0 1 1 1

Or Not

0 0 1 1

0 1 0 1

1 0 1 1

Exclusive Or

0 0 1 1

0 1 0 1

0 1 1 0

Exclusive Or Not

0 0 1 1

0 1 0 1

1 0 0 1

Mnemonic A

AN

O

ON

X

XN

Addresses of Basic Functions (A, AN, O, ON, X, XN)

The address of an instruction can be a bit, a timer or a counter. The instruction accesses the contact with one of these addressing types:
The address identifier and the address within the memory area defined by the address identifier (see Tables 5-1 and 5-3).
Bit, timer or counter transferred as parameter (see Table 5-4).
Conditions, expressed in bits of the status word (see Table 5-8).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-3

Bit Logic Instructions

Table 5-1

Addresses: Direct and Indirect Addressing Maximum Address Range According to Addressing Type

Address ID

Direct

I Q

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

M

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

DBX DIX L

Table 5-2

Memory Indirect

[AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit]

Addresses: Area-Crossing Register Indirect Addressing Address Identifier1

Maximum Address Range [AR1, P#byte.bit] [AR2, P#byte.bit]

I, Q, M, DBX, DIX, or L 1

Register Indirect, Area-Internal

0.0 to 8,191.7

The memory area is encoded in pointer bits 24, 25, and 26 (see Section 3.6).

Table 5-3

Addresses: Timers and Counters Maximum Address Range According to Addressing Type

Address Ident Identifier f er

Direct

T C

Table 5-4

0 to 65,535

Symbolic name

5-4

[DBW] [DIW] [LW] [MW]

0 to 65,534

Address: Bit, Timer, or Counter Transferred as Parameter

Address

Table 5-5

Memory Indirect

Address Parameter Format A bit, timer, or counter transferred as parameter

Addresses of Boolean Bit Logic Instructions: Bits of the Status Word

Memory Area or Reference to a Location

Bits of the Status Word

>0, <0, <>0, >=0, <=0, ==0

7 and 6: condition codes 1 and 0 (memory area)

UO

7 and 6: condition codes 1 and 0 (memory area)

BR

8: binary result (location)

OV

5: overflow (location)

OS

4: overflow, stored (location)

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Change of Bits in the Status Word

Instruction

OR

STA

RLO

FC

A AN A( AN(

x x 0 0

x x 1 1

x x – –

1 1 0 0

O ON O( ON(

0 0 0 0

x x 1 1

x x – –

1 1 0 0

X XN X( XN(

0 0 0 0

x x 1 1

x x – –

1 1 0 0

=

0

x

–

0

CLR

0

0

0

0

FN

0

x

x

1

FP

0

x

x

1

NOT

–

1

x

–

R

0

x

–

0

S

0

x

–

0

SAVE

–

–

–

–

SET

0

1

1

0

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-5

Bit Logic Instructions

5.2

Bit Logic Instructions and Relay Coil Circuit

Introduction

Bit logic instructions are also named relay logic instructions as they can execute commands which can replace the function of a relay logic circuit. The following explains how a relay logic circuit can be reproduced with STL commands.

Normally Open Contact

Figure 5-1 shows a relay logic circuit with normally open control relay contact between a power rail and a coil. The normal state of this contact is open. If the contact is not activated, it remains open. The signal state of the open contact is 0 (not activated). If the contact remains open, the power from the power rail cannot energize the coil at the end of the circuit. If the contact is activated (signal state of the contact is 1), power will flow to the coil.

Power Rail Normally Open Contact

Coil

Figure 5-1

I 1.1

Q 4.0

Relay Logic Circuit with Normally Open Control Relay Contact

You can use an And (A) or an Or (O) instruction to check the signal state of a normally open control relay contact. If the normally open contact (I1.1 = 0) is open the check result is “0”, if it is closed the result is “1”.

5-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Normally Closed Contact

Figure 5-2 shows the representation of a relay logic circuit with normally closed control relay contact between a power rail and a coil. The normal state of this contact is closed. If the contact is not activated, it remains closed. The signal state of the closed contact is 0 (not activated). If the contact remains closed, power from the power rail can cross the contact to energize the coil at the end of the circuit. Activating the contact (signal state of the contact is 1) opens the contact, interrupting the flow of power to the coil.

Power Rail Normally Closed Contact

I 1.1

Coil

Figure 5-2

Q 4.0

Relay Logic Circuit with Normally Closed Control Relay Contact

You can use an And Not (AN) or an Or Not (ON) instruction to check the signal state of a normally closed control relay contact. If the normally closed contact is closed (I1.1 = 0) the check result is “1”, if it is open the result is “0”.

Power Flow in a Series Circuit

Figure 5-3 shows an example with a statement list that uses an AND instruction (A) to program two normally open contacts in series. Only when the signal state of both the normally open contacts is “1”, can the state of output Q4.0 be set to “1” and the coil be energized. Statement List Program

A I 1.0

I 1.0

A I 1.1

I 1.1

= Q 4.0

Q 4.0

Figure 5-3

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Relay Logic Diagram

Using the And Instruction to Program Contacts in Series

5-7

Bit Logic Instructions

Power Flow in a Parallel Circuit

Figure 5-4 shows a statement list that uses an Or instruction (O) to program each of two normally open contacts connected in parallel to a coil. Only when the signal state of one of the normally open contacts is “1”, can the state of output Q4.0 be set to “1” and the coil be energized. Statement List Program

Relay Logic Diagram Power Rail I 1.0

I 1.1

O I 1.0 O I 1.1 = Q 4.0

Figure 5-4

Exclusive Or

Q 4.0

Using the Or Instruction to Program Contacts in Parallel

The Exclusive Or (X) instruction in STL corresponds to a relay logic circuit, as in Figure 5-5, in which a normally closed contact and a normally open contact are connected. Q4.0 is “1” when I1.0 and I1.0 have different values. Statement List Program

Relay Logic Diagram Power Rail

X I 1.0 X I 1.1 = Q 4.0

Contact I 1.0 Contact I 1.1

Coil Q 4.0

Figure 5-5

5-8

Using the Exclusive Or instruction to Program Contacts in Parallel

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

AN, ON, XN

Similarly the following instructions can affect other actions: AN: Affects the series connection of a normally closed contact..

Statement List Program

Relay Logic Diagram Power Rail

ON: Affects the parallel connection of a normally closed contact.

A I 1.0

I 1.0 Normally Open Contact

AN I 1.1

I 1.1 Normally Closed Contact

= Q 4.0

Q 4.0 Coil

Statement List Program

Relay Logic Diagram Power Rail

XN: Affects the interconnected series connection of a normally closed contact and a normally open contact.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

O I 1.0

I 1.0 Normally Open Contact

ON I 1.1

I 1.1 Normally Closed Contact

= Q 4.0

Q 4.0 Coil

Statement List Program

Relay Logic Diagram Power Rail

X I 1.0

I 1.0 Normally Open Contact

XN I 1.1

I 1.1 Normally Closed Contact

= Q 4.0

Q 4.0 Coil

5-9

Bit Logic Instructions

5.3

Evaluating Conditions Using And, Or, and Exclusive Or

Description

With the bit logic instructions you can check the bits of the status word CC 0, CC 1, BR, OV and OS. These can be influenced by the following instructions (Table 5-6). Table 5-6

Instructions That Affect the CC, BR, OV, and OS Bits of the Status Word

Type of Instruction

5-10

Instruction

Section in This Manual

Integer Four-Function Math


I, I, /I,I,
D, D, /D,D, MOD

9.1

Integer Comparisons (Integer Math Instructions)

==I, <>I, I, >=I, ==D, <>D, D, >=D

11.2

Floating-Point Math


R, R,R , /R, SQRT, SQR, LN, EXP, SIN, COS, TAN, ASIN, ACOS, ATAN

10.1

Floating-Point Comparisons

==R, <>R, R, >=R

11.3

Conversion

BTI, BTD, RND, RND, RND
, TRUNC, NEGI, NEGD

12.1, 12.2, and 12.4

Shift and Rotate Functions

SLW, SRW, SLD, SRD, SSI, SSD, RLD, RRD, RLDA, RRDA

14.1 and 14.2

Word Logic

AW, OW, XOW, AD, OD, XOD

13.2

Nesting

)

5.4

Saving the RLO to BR Register

SAVE

5.9

Logic Control

JCB, JNB, SPS

16.1

Program Control

BEB, BE, BEA, CC, UC

17.6

Transfer

T STW

8.3

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Relationship of a Result to 0

The combination of bits CC 1 and CC 0 in the status word can easily be checked using “replacement addresses” (for example, >0, ==0, <0, etc.). Table 5-7 shows the connection between different bit combinations and simple checking. For example, you can check the combination CC 1 = 0 and CC 0 = 1 in an And instruction with A <0. Table 5-7 Combination States of CC 0 and CC 1 and Relevant Check Option

If the following signal combination is in the status word ...

... the check can be carried out using

Signal State of CC 1

Signal State of CC 0

1

0

>0

0

1

<0

0 or 1

1 or 0

<>0

1 or 0

0 or 0

>=0

0 or 0

1 or 0

<=0

0

0

==0

1

1

UO

STL

Explanation

L +10 //LOWER LIMIT

Load the integer 10 into accumulator 1 low as a lower limit.

L MW30

Load the value in memory word MW30 into accumulator 1 low, transferring the integer value 10 to accumulator 2 low.

<=I

Is 10 less than or equal to the value in MW30? If yes, then set the RLO to 1; otherwise reset the RLO to 0.

L +100 //UPPER LIMIT

Load the integer 100 into accumulator 1 low as an upper limit, transferring the value from MW30 stored in accumulator 1 low to accumulator 2 low.

–I

Subtract 100 from the value in MW30. The result sets CC 1 and CC 0 with a bit combination that shows how the result compares to 0 (see Table 5-7). The RLO is not changed.

U <=0

According to the bit combination in CC 1 and CC 0, is the condition <= 0 fulfilled? Yes produces a 1; no produces a 0 (see Table 5-7). Combine this 1 or 0 with the RLO according to the And truth table, Store the result in the RLO bit.

= Q 4.0

Write the value of the RLO to the signal state of output Q 4.0. The coil at output Q 4.0 is energized (has a signal state of 1) if the value in MW30 is greater than or equal to 10 and less than or equal to 100.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-11

Bit Logic Instructions

The Boolean bit logic instructions can also enable your program to react if the result of a floating-point math operation is illegal because one of the numbers is not a valid floating-point number (unordered, UO). The instruction checks the signal state of bits CC1 and CC0 of the status word (see Table 5-7).

Overflow and Binary Result

Some of the instructions listed in Table 5-6 can set the binary result bit (BR) or the overflow bits (OV and OS) of the status word to 1. You can use the A, AN, O, ON, X, and XN bit logic instructions together with the following memory areas to enable your program to react to an overflow or to a binary result bit that is set to 1.

STL

Explanation

L MW10

Load the integer in MW10 into accumulator 1 low.

L MW20

Load the integer in MW20 into accumulator 1 low, transferring the value from MW10 to accumulator 2.

+I

Add the two integer values in the accumulators.

T MW30

Transfer the result from accumulator 1 low to MW30.

A I 0.0

Check the signal state at input I 0.0 for 1 or 0.

A OV

Check the OV bit of the status word for 1 or 0.

= Q 4.0

If the signal state of I 0.0 is 1 and there is a 1 in the OV bit of the status word (i.e., an overflow occurred during the last math operation), set the signal state of output Q 4.0 to 1; otherwise set it to 0.

STL

Explanation

A BR

Check the BR bit of the status word for 1 or 0.

= Q 4.0

If there is a 1 in the BR bit of the status word, set the signal state of output Q 4.0 to 1; otherwise set it to 0.

5-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Addressing the Bits of the Status Word

The Boolean bit logic instructions evaluate conditions by using the addresses shown in Table 5-8. Table 5-8

Addresses of Boolean Bit Logic Instructions: Bits of the Status Word

Memory Area or Reference to a Location

Bit(s) of Status Word

>0, <0, <>0, >=0, <=0, ==0

7 and 6: condition codes 1 and 0 (memory area)

UO

7 and 6: condition codes 1 and 0 (memory area)

BR

8: binary result (location)

OV

5: overflow (location)

OS

4: overflow, stored (location)

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-13

Bit Logic Instructions

5.4

Nesting Expressions and And before Or

Description

You can use the And (A), Or (O), and Exclusive Or (X) instructions and their negated forms AN, ON, XN to perform Boolean logic operations on portions of a logic string that are enclosed in parentheses (nesting expressions). Parentheses around a portion of a logic string indicate that your program will perform the operations inside the parentheses before performing the logic operation indicated by the instruction that precedes the nesting expression. You can also combine And and Or statements in a Boolean logic string without using parentheses. By convention, the And statements are evaluated first and the results are then combined according to the Or truth table.

Result of Logic Operation

The instruction that opens a nesting expression stores the RLO from the preceding operation in the nesting stack. Later, the program will combine this stored RLO with the result produced by the logic combinations performed inside the parentheses.

STL

Description

A( O I 0.0

The statements between A( and ) make up a normal Or combination. The result of the first check is stored in the RLO bit.

O M 10.0 )

According to the Or truth table, the result of check is combined with the RLO formed by the previous statement. This combination forms a new result that replaces the value in the RLO bit.

A(

A( copies the value currently in the RLO bit, stores it in the nesting stack, and ends the previous logic string. Therefore the next logic statement begins a new logic string, making a “first check.”

O I 0.2

The statements between A( and ) make up a normal Or combination. The result of the first check is stored in the RLO bit.

O M 10.3

According to the Or truth table, the result of check is combined with the RLO formed by the previous statement. This combination forms a new result that replaces the value in the RLO bit.

)

The ) statement combines the RLO that is stored in the nesting stack (see the A( instruction above) with the current RLO according to the And truth table. This statement uses the And truth table because the ) ends a nesting expression that began with A. This logic combination forms a new RLO.

A M 10.1

This normal And statement combines the new RLO formed in the ) instruction above with the result of its check according to the And truth table.

= Q 4.0

The Assign instruction (=, see Section 5.8) assigns the value of the RLO to the output coil.

5-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

And before Or

The following statement list uses the principle of And before Or to program a circuit. By convention, the program evaluates the And statements first. Then the program combines the results of the And operation according to the Or truth table. No parentheses are needed. The principle at work here is called “And before Or.”

STL

Description

A I 0.0

The result of the first check is stored in the RLO bit.

A M 10.0

According to the And truth table, the result of check is combined with the RLO formed by the previous statement. This combination forms a new result that replaces the value in the RLO bit.

O

The statement O copies the value currently in the RLO bit, stores it in the Or bit and ends the previous logic string. The statement “O” secures the RLO as one of the two values that it will use to carry out an Or operation, according to the principle “And before Or”.

A I 0.2

The result of the first check is stored in the RLO bit. In each And operation which follows an Or operation the newly formed RLO is combined with the Or bit.

A M 0.3

According to the And truth table, the result of check is combined with the RLO formed by the previous statement. This combination forms a new result that replaces the value in the RLO bit. In each And operation the newly formed RLO is combined with the Or bit. The first “O” operation fetches the stored RLO from the nesting stack and combines it with the current RLO. This operation results to a new value which is stored in the RLO bit as the result of an “And before Or” operation. (There is no special operation to end an “And before Or” operation. A special bit processor in the programmable controller finds the last A operation in an “And before Or” operation. The operation that follows the last A operation (e.g. =, S, R or O) ends the “And before Or” operation automatically with the estimation of the RLO.)

O M 10.1

The next “O” operation combines the result of the ”And before Or” operation with the check result of the second “O” operation.

= Q 4.0

The Assign instruction (=, see Section 5.8) assigns the value of the RLO to the output coil.

Output Q 4.0 is energized (its signal state is 1) if the result of either one or the other pair of And operations is 1 or if the result of the normal Or operation on M 10.1 is 1.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-15

Bit Logic Instructions

5.5

Instructions for Transitional Contacts: FP, FN

Description

You can use the Edge Positive (FP) and Edge Negative (FN) instructions like transition-sensing contacts in a relay circuit. These instructions detect and react to transitions in the result of logic operation. A transition from 0 to 1 is called a “positive edge.” A transition from 1 to 0 is called a “negative edge” (see Figure 5-6).

Positive Edge

RLO

Negative Edge

1 0 Figure 5-6

Reacting to a Positive Edge

Time Representation of Positive and Negative Edges

Figure 5-7 shows a statement list that enables your program to react to a positive edge transition. An explanation follows the figure. Statement List

Signal State Diagram

A
I
1.0

I 1.0

FP M 1.0

M 1.0

= Q 4.0

Q 4.0

OB1 Scan Cycle No.: Figure 5-7

1 0 1 0 1 0 1

2

3

4

5

6

7

8

9

Programming a Reaction to a Positive Edge Transition

If the programmable logic controller detects a positive edge at contact I 1.0, it energizes the coil at Q 4.0 for one OB1 scan cycle. The programmable logic controller stores the result of the logic operation performed by the A instruction in edge memory bit M 1.0 and compares it to the RLO from the previous scan cycle. (In the example in Figure 5-7, the RLO of the statement “A I 1.0” just happens to be the same as the signal state of input I 1.0. This will not be the case for every program.) If the current RLO is 1 and the RLO from the previous scan cycle stored in memory bit M 1.0 is 0, then the FP statement sets the RLO to 1. The FP statement detects a positive edge at the contact (that is, the signal state of the RLO changed from 0 to 1). If there is no change in the RLO (current RLO and previous RLO stored in the edge memory bit are both equal to 0 or 1), then the FP statement resets the RLO to 0.

5-16

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Table 5-9 OB1 Scan Cycle No.

Checking for Positive Edge Transition at Input I 1.0 Signal State at Input in Previous Cycle

Signal State at Did the signal Input in state change Current Cycle from 0 to 1?

Is the coil at Q 4.0 energized?

1

0 (default value)

0

No

No

2

0

1

Yes

Yes

3

1

1

No

No

4

1

0

No

No

5

0

0

No

No

6

0

1

Yes

Yes

7

1

0

No

No

8

0

1

Yes

Yes

9

1

1

No

No

Table 5-9 applies specifically to the statement list program shown in Figure 5-7. In general, you should consider the transitions detected by FP and FN to be transitions reflected in the RLO, not in the signal states of contacts. For example, a logic string can form an RLO that is not directly related to the signal state of a contact.

Reacting to a Negative Edge

Figure 5-8 shows a statement list that enables your program to react to a negative edge transition. An explanation follows the figure. Statement List

Signal State Diagram

A
I
1.0

I 1.0

FN M 1.0

M 1.0

= Q 4.0

Q 4.0

OB1 Scan Cycle No.: Figure 5-8

1 0 1 0 1 0 1

2

3

4

5

6

7

8

9

Programming a Reaction to a Negative Edge Transition

If the programmable logic controller detects a negative edge at contact I 1.0, it energizes the coil at Q 4.0 for one OB1 scan cycle. The programmable logic controller stores the result of the logic operation performed by the A instruction in edge memory bit M 1.0 and compares it to the RLO from the previous scan cycle (see Table 5-10). (In the example in Figure 5-8, the RLO of the statement “A I 1.0” just happens to be the same as the signal state of input I 1.0. This will not be the case for every program.) If the current RLO is 0 and the RLO from the previous scan cycle stored in memory bit M 1.0 is 1, then the FN statement sets the RLO to 1.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-17

Bit Logic Instructions

The FN statement detects a negative edge at the contact (that is, the signal state of the RLO changed from 1 to 0). If there is no change in the RLO (current RLO and previous RLO stored in the edge memory bit are both equal to 0 or 1), then the FN statement resets the RLO to 0. Table 5-10 OB1 Scan Cycle No.

Checking for Negative Edge Transition at Input I 1.0 Signal State at Input in Previous Cycle

Signal State at Did the signal Input in state change Current Cycle from 1 to 0?

Is the coil at Q 4.0 energized?

1

0 (default value)

0

No

No

2

0

1

No

No

3

1

0

Yes

Yes

4

0

0

No

No

5

0

1

No

No

6

1

1

No

No

7

1

1

No

No

8

1

0

Yes

Yes

9

0

0

No

No

Table 5-10 applies specifically to the statement list program shown in Figure 5-8. In general, you should consider the transitions detected by FP and FN to be transitions reflected in the RLO, not in the signal states of contacts. For example, a logic string can form an RLO that is not directly related to the signal state of a contact.

Addressed Bit

The location that the FP or FN instruction addresses is a bit. The instruction accesses the output through one of the following types of addresses:


Address identifier (ID) and location within the memory area that is indicated by the address identifier (see Tables 5-11 and 5-12)


Bit transferred as a parameter (see Table 5-13)

5-18

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Table 5-11

Maximum Address Range According to Addressing Type

Address ID1

Direct

I2 Q3 M DBX DIX 1 2

3

!

Addresses of FP and FN: Direct and Indirect Addressing

0.0 to 65,535.7

Memory Indirect [DBD] [DID] [LD] [MD]

Area-Internal Register Indirect [AR1, P#byte.bit]

0 to 65,532

0.0 to 8,191.7 [AR2, P#byte.bit]

See the Caution that follows this table. Because the operating system overwrites the process-image input table at the beginning of every scan cycle, the RLO stored by an FP or FN instruction that uses an input bit as its address is corrupted. See the Caution that follows this table. Using an output bit as the address of an FP or FN instruction is not recommended. If you want to influence an output, use the S, R, or = instruction.

Caution Corruption of stored result of logic operation. Can cause minor property damage. If you use an FP or FN instruction in your program, the memory bit that is the address of this instruction is used by FP or FN exclusively for its own storage purposes. Therefore you should not use any instruction that would change this bit. Otherwise you will corrupt the stored RLO. This caution applies to all the memory areas indicated in the address identifiers listed in Table 5-11.

Table 5-12

Addresses of FP and FN: Area-Crossing Register Indirect Addressing

Address Identifier1 I, Q, M, DBX, or DIX 1

Address Range [AR1, P#byte.bit] [AR2, P#byte.bit]

0.0 to 8,191.7

The memory area is encoded in AR1 or AR2, respectively (see Section 3.6).

Table 5-13

Addresses of FP and FN: Bit Transferred as Parameter

Address Symbolic name

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Address Parameter Format A bit transferred as parameter

5-19

Bit Logic Instructions

5.6

Output of Boolean Logic String

Description

You can terminate a Boolean bit logic string by using one of the following three statement list instructions. Each of these instructions can influence a bit that represents the end of that string.


Set (S): if the RLO was set to 1 in the previous command, S sets the signal state of the contact or coil that the instruction addresses to 1;


Reset (R): if the RLO was set to 1 in the previous command, R resets the signal state of the contact or coil that the instruction addresses to 0;


Assign (=): independently of the state of the RLO, the value of the RLO is assigned to the location that the instruction addresses.

Terminating a Logic String

A logic string is terminated when the first-check bit (FC bit) is reset. When the value in the FC bit is 0, this indicates that the next instruction in the program is the first instruction of a new logic string (see Section 2.2, First Check). A Set (S), Reset (R), or Assign (=) instruction terminates a logic string by resetting the first-check bit (FC bit) to 0. (Conditional jump instructions also reset the FC bit to 0, see Sections 16.3 through 16.5.) Logic strings that are started with the instructions A(, AN(, O( etc. must be terminated with the ) instruction. Because these commands can also be used in the middle of a logic string, they represent an interruption in the string. That means that a new logic string is started before the old one is terminated. To continue the old logic string in the correct order after closing the commands to be carried out in brackets, the old FC bit (saved by opening the brackets) is restored again. You can therefore imagine program sections within brackets as a sort of intermediate calculation which, once completed, pick up the old thread again.

5-20

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

5.7

Set and Reset Instructions: S and R

Description

You can use the Set (S) instruction to set the signal state of an addressed bit to 1. (For information on the S instruction for setting an addressed counter to a specific value, see Section 7.2). You can use the Reset (R) instruction to reset the signal state of an addressed bit to 0. R can also reset an addressed timer or counter to 0 (see Sections 6.3 and 7.2). S and R terminate a logic string (see Section 5.6).

Setting a Bit

The S instruction sets the bit that it addresses to 1 if the result of logic operation from the previous statement is 1 and the master control relay (MCR) is energized (that is, its signal state is 1). If the MCR is not energized (its signal state is 0), the addressed bit is not changed. The S instruction terminates a logic string. Figure 5-9 illustrates how the S instruction holds the signal state of its addressed coil Q 4.0 at 1 until the R instruction changes the signal state to 0. The fact that the signal state of the addressed coil remains at 1 until an R instruction resets it to 0 indicates the static nature of the S instruction. In the relay logic diagram, if the normally open contact at input I 1.0 is activated (its signal state becomes 1), the contact closes. Power flows across the contact at I 1.0 and across the normally closed contact beneath it, energizing the coil at output Q 4.0 (the signal state of Q 4.0 becomes 1). When the coil is energized, the normally open contact at output Q 4.0 across from I 1.0 is closed. After that, regardless whether the contact at input I 1.0 is opened or closed, the coil at output Q
4.0 remains energized (at signal state
1). The coil keeps itself energized.

Statement List A I 1.0 S Q 4.0 A I 1.1 R Q 4.0

Signal State Diagrams I 1.0

Relay Logic Diagram Power Rail I 1.0 Normally Open Contact 1 0 1

I 1.1

0

Q 4.0

I 1.1

Normally Closed Contact Q 4.0 Coil

1 Q 4.0

Figure 5-9

0

Setting and Resetting a Bit Statically

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-21

Bit Logic Instructions

Resetting a Bit

The R instruction resets the bit that it addresses to 0 if the result of logic operation from the previous statement is 1 and the master control relay (MCR) is energized (that is, its signal state is 1). If the MCR is not energized (its signal state is 0), the addressed bit is not changed. The R instruction terminates a logic string. Figure 5-9 illustrates how the R instruction holds the signal state of its addressed coil Q 4.0 at 0 regardless of a change in signal state at the contact that triggered the reset (I 1.1). The fact that the signal state of the addressed coil remains at 0 until an S instruction resets it to 1 indicates the static nature of the R instruction. In the relay logic diagram, the coil at output Q 4.0 that was energized by the S instruction is de-energized (its signal state becomes 0) by closing the normally open contact at input I 1.1. Closing contact I 1.1 allows power to flow to the coil beneath it. This coil opens the normally closed contact above the coil at Q 4.0, interrupting the flow of power to the coil. Closing contact I 1.1 triggers the R instruction.

Referenced Address

The address that the S instruction references can be a bit. The address that the R instruction references can be a bit, a timer number, or a counter number. The addresses can be specified as follows:


Address identifier (ID) and location within the memory area that is indicated by the address identifier (see Tables 5-14 through 5-16)


Bit, timer, or counter transferred as a parameter (see Table 5-17) Table 5-14

Maximum Address Range According to Addressing Type

Address ID

Direct

I Q

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

0.0 to 255.7

[DBD] [DID] [LD] [MD]

0 to 65,532

[DBD] [DID] [LD] [MD]

0 to 65,532

M

DBX DIX L

5-22

Addresses of S and R: Direct and Indirect Addressing

0.0 to 65,535.7

Memory Indirect

Area-Internal Register Indirect [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit]

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Table 5-15

Addresses of S and R: Area-Crossing Register Indirect Addressing

Address Identifier1

Maximum Address Range [AR1, P#byte.bit] [AR2, P#byte.bit]

I, Q, M, D, DBX, DIX, or L 1

0.0 to 8,191.7

The memory area is encoded in pointer bits 24, 25, and 26 (see Section 3.6).

Table 5-16

Addresses of R: Timers and Counters Maximum Address Range According to Addressing Type

Address Ident Identifier f er

T1 C

1

Memory Indirect

0 to 65,535

[DW] [DXW] [LW] [MW]

0 to 65,534

The S instruction that sets an addressed bit to 1 does not apply to timers or counters. An S instruction used with a counter sets that counter to a specific value. Timers are started with instructions for specific types of timers (see Sections 6.2, 6.3 and 7.2).

Table 5-17

Address of S and R: Bit, Timer, or Counter Transferred as Parameter

Address Symbolic name 1

Direct

Address Parameter Format A bit, timer,1 or counter transferred as parameter

The S instruction does not apply to timers. Timers are started with instructions for specific types of timers (see Sections 6.2 and 6.3).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-23

Bit Logic Instructions

5.8

Assign Instruction (=)

Description

Each Boolean logic operation produces a result known as the “result of logic operation” (RLO). This RLO is either 1 or 0. In reference to contacts and coils, a 1 indicates power flow; a 0 indicates no power flow. You can use the Assign (=) instruction to copy the RLO from the previous statement in a logic string and assign the RLO as the signal state of the coil that the = instruction addresses. The = instruction terminates a logic string (see Section 5.6).

Setting or Resetting a Bit

The value that the = instruction assigns to the coil that it addresses can be 1 or 0, depending on the RLO of the statement that preceded the = statement. Unlike the instructions S and R, the nature of the = instruction is dynamic. It assigns the RLO as the signal state of the coil that the = instruction addresses. Figure 5-10 shows how this value changes as the RLO of the statement “A I 1.0” changes. In Figure 5-10, the = instruction enables the input signal at the contact I 1.0 to energize or de-energize the coil represented by output Q 4.0 (that is, = sets or resets the bit represented by Q 4.0 by assigning the RLO of the previous statement).

Statement List A I 1.0 = Q 4.0

Relay Logic Diagram Power Rail I 1.1

Signal State Diagrams I 1.0

0 1

Q 4.0

Figure 5-10

5-24

1 Q 4.0 Coil

0 Setting and Resetting a Bit Dynamically

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Addresses

The address that the = instruction addresses can be a bit. The instruction accesses the coil through one of the following addresses:


Address identifier (ID) and location within the memory area that is indicated by the address identifier (see Tables 5-18 and 5-19)


Bit transferred as a parameter (see Table 5-20) Table 5-18

Addresses of =: Direct and Indirect Addressing Maximum Address Range According to Addressing Type

Address ID

Direct

I Q

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

M

0.0 to 65,535

[DBD] [DID] [LD] [MD]

0 to 65,532

0.0 to 65,535.7

[DBD] [DID] [LD] [MD]

0 to 65,532

DBX DIX L

Table 5-19

Memory Indirect

[AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit] [AR1, P#byte.bit] 0.0 to 8,191.7 [AR2, P#byte.bit]

Addresses of =: Area-Crossing Register Indirect Addressing

Address Identifier1 I, Q, M, DBX, DIX, or L 1

Area-Internal Register Indirect

Maximum Range of Address Parameters [AR1, P#byte.bit] [AR2, P#byte.bit]

0.0 to 8,191.7

The memory area is encoded in the uppermost 8 bits of AR1 or AR2, respectively.

Table 5-20

Addresses of =: Bit Transferred as Parameter

Address Symbolic name

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Address Parameter Format A bit transferred as parameter

5-25

Bit Logic Instructions

5.9

Negating, Setting, Clearing, and Saving the RLO

Description

You can use one of the following instructions to change the result of logic operation (RLO) stored in the RLO bit in the status word of the programmable logic controller (see Section 5.8): Mnemonic

Instruction

Meaning

NOT

Negate RLO

Negating (inverting) the current RLO

SET

Set RLO

Setting the current RLO to 1

CLR

Clear RLO

Resetting the current RLO to 0

SAVE

Save RLO in BR Register Saving the current RLO to the bit of the status word

Because these instructions affect the RLO directly, they have no addresses.

Negating the RLO

You can use the Negate RLO (NOT) instruction in your program to negate (invert) the current RLO. If the current RLO is 0, NOT changes it to 1; if the current RLO is 1, NOT changes it to 0, provided the OR bit is not set. This instruction is useful for shortening your program, for example by changing from positive logic to negative logic (see the timer example in Section B.3).

Setting the RLO to 1

You can use the Set RLO (SET) instruction in your program if you need to set the RLO bit to 1 unconditionally. Figure 5-11 shows how the SET instruction works in a program.

Clearing the RLO to 0

You can use the Clear RLO (CLR) instruction in your program if you need to reset the RLO bit to 0 unconditionally. CLR also resets the FC, OR, and STA bits to 0. As a result, the logic string is ended. Figure 5-11 shows how the CLR instruction works in a program.

Saving the RLO

You can use the Save RLO in BR Register (SAVE) instruction in your program if you need to save the RLO for future use or if you want to influence the BR bit of the status word in the programmable logic controller, for example when you are programming function blocks (FBs) and functions (FCs) for ladder logic programming boxes. Influence on the Bits of the Status Word

Instruction BR

OR

STA

RLO

FC

NOT

–

1

x

–

SET

0

1

1

0

CLR

0

0

0

0

SAVE

5-26

A1

A0

OV

OS

x

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit Logic Instructions

Applying SET and CLR

The program shown in Figure 5-11 illustrates an application of the SET and CLR instructions that set and reset a bit unconditionally.

Statement List

Signal State

SET

1

= M 10.0

1

= M 15.1

1

= M 16.0

1

CLR

0

= M 10.1

0

= M 10.2

0

Figure 5-11

Result of Logic Operation (RLO)

Setting and Resetting a Bit Unconditionally Using SET and CLR

You could use the statements in the program shown in Figure 5-11 in a start-up organization block (OB). After you power up your programmable logic controller, it processes the start-up OB with all the instructions that it contains. After the programmable logic controller has executed all the instructions, the following memory bits have a specific signal state regardless of any conditions:


The signal state of memory bits M 10.0, M 15.1, and M 16.0 is 1.
The signal state of memory bits M 10.1 and M 10.2 is 0.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

5-27

Bit Logic Instructions

5-28

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6

Timer Instructions Chapter Overview

Section

Description

Page

6.1

Overview

6-2

6.2

Location of a Timer in Memory and Components of a Timer

6-3

6.3

Loading, Starting, Resetting, and Enabling a Timer

6-5

6.4

Timer Examples

6-7

6.5

Address Locations and Ranges for Timer Instructions

6-17

6.6

Choosing the Right Timer

6-18

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-1

Timer Instructions

6.1

Overview

Definition

A timer is a function element of the STEP 7 programming language that implements and monitors timed sequences. The timer instructions enable your program to perform the following functions:


Provide waiting times. For example, after an injection molding procedure, the mold must remain closed for two seconds. Your program ensures that two seconds elapse before the part is released from the mold.


Provide monitoring times. For example, the program monitors the speed of a motor for 30 seconds after you press the start button.


Generate pulses. For example, the program provides pulses that cause a light to flash.


Measure time. For example, the program can determine how long it takes for a container to be filled.

Available Instructions

The statement list representation of the STEP 7 programming language provides the following timer instructions:


Start timer as one of the following types: – Pulse (SP) – Extended pulse (SE) – On-delay (SD) – Retentive on-delay (SS) – Off-delay (SF)


Reset timer (R)
Enable a timer to start (FR)
Load timer in one of the following formats: – Binary (L) – Binary coded decimal (LC)


Check the signal state of a timer and combine the result in a Boolean logic operation (A, AN, O, ON, X, XN) (see Chapter 11). Figure 6-1 summarizes the instructions that use a timer word as address.

Start timer (SP, SE, SD, SS, SF) Enable timer (FR)

Timer word

Check signal state of timer (A, O, X, AN, ON, XN) Figure 6-1

6-2

Reset timer (R) Load timer (L, LC)

Instructions That Can Use a Timer Word as an Address

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

6.2

Location of a Timer in Memory and Components of a Timer

Area in Memory

Timers have an area reserved for them in the memory of your CPU. This memory area reserves one 16-bit word for each timer address. The statement list instruction set supports 256 timers. To find out how many timer words are available in your CPU, please refer to the CPU technical data. The following functions have access to the timer memory area:


Timer instructions
Updating of timer words via clock timing. This function decrements a given time value by one unit at the interval designated by the time base until the time value is equal to zero.

Time Value

Bits 0 through 9 of the timer word contain the time value in binary code. The time value specifies a number of units. Time updating decrements the time value by one unit at an interval designated by the time base. Decrementing continues until the time value is equal to zero. You can load a time value into the low word of accumulator 1 in binary, hexadecimal, or binary coded decimal (BCD) format. The time range is from 0 to 9,990 seconds. You can pre-load a time value using either of the following syntax formats:


L W#16#wxyz – Where w = the time base (that is, the time interval or resolution) – Where xyz = the time value in binary coded decimal format


L S5T# aH_bbM_ccS_ddMS – Where a = hours, bb = minutes, cc = seconds, and dd = milliseconds – The time base is selected automatically and the value is rounded to the next lower number with that time base. The maximum time value that you can enter is 9,990 seconds, or 2H_46M_30S.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-3

Timer Instructions

Time Base

Bits 12 and 13 of the timer word contain the time base in binary code. The time base defines the interval at which the time value is decremented by one unit. The smallest time base is 10 ms; the largest is 10 s. Table 6-1

Time Base and Its Binary Code Time Base

Binary Code for the Time Base

10 ms

00

100 ms

01

1s

10

10 s

11

Because time values are stored with only one time interval, values that are not exact multiples of a time interval are truncated. Values that have too much resolution for the desired range are rounded down to achieve the desired range but not the desired resolution. Table 6-2 shows the possible resolutions and their corresponding ranges. Table 6-2

Time Base Resolutions and Ranges Range

Resolution 0.01 second

10MS to 9S_990MS

0.1 second

100MS to 1M_39S_900MS

1 second

1S to 16M_39S

10 seconds

Bit Configuration in Accumulator 1

10S to 2HR_46M_30S

When a timer is started, the contents of accumulator 1 are used as the time value. Bits 0 through 11 of accumulator 1 low hold the time value in binary coded decimal format (BCD format: each set of four bits contains the binary code for one decimal value). Bits 12 and 13 hold the time base in binary code (see Table 6-1). Figure 6-2 shows the contents of accumulator 1 low loaded with timer value 127 and a time base of 1 second. (See also Section 8.5.)

15... x

...8 x

1

0

0

0

0 1

1

7... 0

...0 0

1

0

0

2

1

1

1

7

Time value in BCD (0 to 999) Time base 1 second Irrelevant: These bits are ignored when the timer is started. Figure 6-2

6-4

Contents of Accumulator 1 Low: Timer Value 127, Time Base 1 Second

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

6.3

Loading, Starting, Resetting, and Enabling a Timer

Description

To start a timer in your statement list program, include three statements to trigger the following operations:


Check a signal state for 0 or 1 (for example, A I 2.1)
Load a time value and an accompanying time base (for example, L IW0)
Start a timer as one of the following types: – Pulse timer (SP, for example, SP T 1) – Extended pulse timer (SE) – On-delay timer (SD) – Retentive on-delay (SS) – Off-delay (SF) In your statement list program, a change in the result of logic operation (RLO) prior to a Start instruction statement starts a timer. A change in the RLO from 1 to 0 starts an off–delay timer (SF); a change from 0 to 1 starts any of the other timers. The programmed time and the Start timer statements must follow the logic operation directly that provides the condition for starting the timer. Section 6.4 provides examples of the five types of Start instructions for timers. Loading

Loading a time value as an integer or as a BCD number is described in Sections 8.4 and 8.5.

The Starting Time

Because a timer runs down to zero from a set time, you must provide the timer with a starting time. When you start a timer in your program, the CPU looks in accumulator 1 for the starting time. The time range is from 0 to 9,990 seconds.

Example of Starting a Timer

Figure 6-3 provides an example for starting a pulse timer. A change in signal state from 0 to 1 at input I 2.1 starts the timer. Figure 6-3 refers to the following STL program:

STL A L SP

Explanation I 2.1 S5T#00H02M23S00MS T 1

Check the signal state of input I 2.1. Load the starting time into accumulator 1. Start timer T1 as a pulse timer.

Signal state diagram: I 2.1 Check I 2.1 for transition from 0 to 1.

1 0 1 0

Timer is started with the starting time given in accumulator 1. Figure 6-3

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Starting a Pulse Timer

6-5

Timer Instructions

Resetting a Timer

You reset a timer by using the Reset (R) instruction. The CPU resets a timer when the result of logic operation is 1 immediately before the R instruction in your program. As long as the RLO that comes before an R instruction statement is 1, an A, O, or X instruction that checks the signal state of a timer produces a result of 0 and an AN, ON, or XN instruction that checks the signal state of a timer produces a result of 1. Resetting a timer stops the current timing function and resets the time value to 0.

Enabling a Timer for Restart

A change in the result of logic operation from 0 to 1 in front of an Enable instruction (FR) enables a timer. This change in signal state is always necessary to enable a timer. The CPU executes the FR instruction only on a positive signal edge. Timer enable is not required to start a timer, nor is it required for normal timer operation. An enable is used only to retrigger a running timer, that is, to restart the timer. This restarting is possible only when the start operation continues to be processed with an RLO of 1.

6-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

6.4

Timer Examples

Introduction

Statement list programming offers five types of timers to meet your automation needs. An example for each type is provided below.

Pulse Timer: SP

Figures 6-4 and 6-5 provide examples of a pulse timer. The numbers in squares in the figures are keyed to explanations that follow Figure 6-4. The figures refer to the following STL program:

STL A FR A L SP A R A = L T LC T

Explanation I 2.0 T 1 I 2.1 S5T#0H2M23S0MS T 1 I 2.2 T 1 T 1 Q 4.0 T 1 MW10 T 1 MW12

RLO at Enable input

Enable timer T 1.

Start timer T 1 as a pulse timer. Reset timer T 1. Check the signal state of timer T 1.

Load timer T 1.

I 2.0


RLO at Start input

I 2.1

RLO at Reset input

I 2.2









 

Timer response Check signal state of timer output.

t Q 4.0



Load timer: L, LC t = programmed start time Figure 6-4

Pulse Timer Example, Part 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-7

Timer Instructions

The following list describes the elements of Figures 6-4 and 6-5:


A change in the RLO from 0 to 1 at the Start input starts the timer. The programmed time t then elapses.



When an RLO of 0 is applied to the Start input, the timer is reset.



Checking the signal state of output Q 4.0 of the timer results in a signal state of 1 for the entire duration of the timer operation.



If an RLO of 1 is applied to the Reset input, the timer is reset. As long as a signal state of 1 remains at the Start input, a change in the RLO from 1 to 0 at the Reset input has no influence on the timer.



A change in the RLO from 0 to 1 at the Start input with the Reset signal applied causes the timer to start momentarily but to reset immediately because of the Reset statement that follows directly in the program (shown as a pulse line in the timing diagram in Figure 6-4). No checking result is obtained for this pulse, provided that the sequence of writing the statements as they appear above is observed.



A change in the RLO from 0 to 1 at the Enable input while the timer is running restarts the timer. The time that is programmed is used as the current time for the restart. A change in the RLO from 1 to 0 at the Enable input has no effect.



If the RLO changes from 0 to 1 at the Enable input while the timer is not running and there is still an RLO of 1 at the Start input, the timer will also be started as a pulse with the time programmed.



A change in the RLO from 0 to 1 at the Enable input while there is still an RLO of 0 at the Start input has no effect on the timer. 

RLO at Enable input

I 2.0

RLO at Start input

I 2.1

RLO at Reset input

I 2.2








Timer response Check signal state of timer output.

t

t

Q 4.0

Load timer: L, LC t = programmed start time Figure 6-5

6-8

Pulse Timer Example, Part 2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

Extended Pulse Timer: SE

Figures 6-6 and 6-7 provide examples of an extended pulse timer. The numbers in squares in the figures are keyed to explanations that follow Figure 6-6. The figures refer to the following STL program:

STL A FR A L SE A R A = L T LC T

Explanation I 2.0 T 1 I 2.1 S5T#0H2M23S0MS T 1 I 2.2 T 1 T 1 Q 4.0 T 1 MW10 T 1 MW12

Enable timer T 1.

Start timer T 1 as an extended pulse timer. Reset timer T 1. Check the signal state of timer T 1. Load timer T 1 (binary coded).

Load timer T 1 (BCD coded).

RLO at Enable input I 2.0 RLO at Start input RLO at Reset input

















I 2.1 



I 2.2

Timer response Check signal state of timer output Q 4.0

t 

Load timer: L, LC t = programmed start time Figure 6-6

Extended Pulse Timer Example, Part 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-9

Timer Instructions

The following list describes the elements of Figures 6-6 and 6-7:

RLO at Enable input




A change in the RLO from 0 to 1 at the Start input starts the timer. The programmed time t then elapses, regardless of a change in the RLO from 1 to 0 at the Start input.



If the RLO changes from 0 to 1 before the time has elapsed, the timer is retriggered with the time that was programmed originally.



Checking the signal state of the timer output produces a result of 1 for the entire duration of the timer operation.



If an RLO of 1 is applied to the Reset input, the timer is reset. As long as a signal state of 1 remains at the Start input, a change in the RLO from 1 to 0 at the Reset input has no effect on the timer.



A change in the RLO from 0 to 1 at the Start input with the Reset signal applied causes the timer to start momentarily but to reset immediately because of the Reset statement that follows directly in the program (shown as a pulse line in the timing diagram in Figure 6-6). No checking result is obtained for this pulse, provided that the sequence of writing the statements as they appear above is observed.



A change in the RLO from 0 to 1 at the Enable input while the timer is running restarts the timer. The time that is programmed is used as the current time for the restart. A change in the RLO from 1 to 0 at the Enable input has no effect.



If the RLO changes from 0 to 1 at the Enable input while the timer is not running and there is still an RLO of 1 at the Start input, the timer will also be started as a pulse with the time programmed.



A change in the RLO from 0 to 1 at the Enable input while there is still an RLO of 0 at the Start input has no effect on the timer. 







I 2.0


RLO at Start input

I 2.1

RLO at Reset input

I 2.2

Timer response Check signal state of timer output.

t

t

t

Q 4.0

Load timer: L, LC t = programmed start time Figure 6-7

6-10

Extended Pulse Timer Example, Part 2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

On-Delay Timer: SD

Figures 6-8 and 6-9 provide examples of an on-delay timer. The numbers in squares in the figures are keyed to explanations that follow Figure 6-8. The figures refer to the following STL program:

STL A FR A L SD A R A = L T LC T

Explanation I 2.0 T 1 I 2.1 S5T#0H2M23S0MS T 1 I 2.2 T 1 T 1 Q 4.0 T 1 MW10 T 1 MW12

Enable timer T 1.

Start timer T 1 as an on-delay timer. Reset timer T 1. Check the signal state of timer T 1.

Load timer T 1.

RLO at Enable input I 2.0 RLO at Start input RLO at Reset input






I 2.1






 



I 2.2 

Timer response t

t

Check signal state of timer output Q 4.0 Load Timer: L, LC t = programmed start time Figure 6-8

On-Delay Timer Example, Part 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-11

Timer Instructions

The following list describes the elements of Figures 6-8 and 6-9:

RLO at Enable input




A change in the RLO from 0 to 1 at the Start input starts the timer. The programmed time t then elapses.



When an RLO of 0 is applied to the Start input, the timer is reset.



Checking the signal state of output Q 4.0 of the timer results in a signal state of 1 when the time has elapsed and the Start input is 1.



If an RLO of 1 is applied to the Reset input, the timer is reset. As long as a signal state of 1 remains at the Start input, a change in the RLO from 1 to 0 at the Reset input has no effect on the timer.



A change in the RLO from 0 to 1 at the Start input with the Reset signal applied causes the timer to start momentarily but to reset immediately because of the Reset statement that follows directly in the program (shown as a pulse line in the timing diagram in Figure 6-8). No checking result is obtained for this pulse, provided that the sequence of writing the statements as they appear above is observed.



A change in the RLO from 0 to 1 at the Enable input while the timer is running restarts the timer. The time that is programmed is used as the current time for the restart. A change in the RLO from 1 to 0 at the Enable input has no effect.



If the RLO changes from 0 to 1 at the Enable input following normal operation of the timer, the timer is not affected



A change in the RLO from 0 to 1 at the Enable input after the timer was reset and while there is still an RLO of 1 at the Start input starts the timer. The time that is programmed is used as the current time. 





I 2.0


RLO at Start input

I 2.1

RLO at Reset input

I 2.2



Timer response Check signal state Q 4.0 of timer output.

t

Load timer: L, LC t = programmed start time Figure 6-9

6-12

On-Delay Timer Example, Part 2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

Retentive On-Delay Timer: SS

Figures 6-10 and 6-11 provide examples of a retentive on-delay timer. The numbers in squares in the figures are keyed to explanations that follow Figure 6-10. The figures refer to the following STL program:

STL A FR A L SS A R A = L T LC T

Explanation I 2.0 T 1 I 2.1 S5T#0H2M23S0MS T 1 I 2.2 T 1 T 1 Q 4.0 T 1 MW10 T 1 MW12

Enable timer T 1.

Start timer T 1 as a retentive on-delay timer. Reset timer T 1. Check the signal state of timer T 1.

Load timer T 1.

RLO at Enable input I 2.0 RLO at Start input RLO at Reset input









I 2.1 





I 2.2

Timer response t Check signal state of timer output Q 4.0



Load timer: L, LC t = programmed start time Figure 6-10

Retentive On-Delay Timer Example, Part 1

The following list describes the elements of Figures 6-10 and 6-11:


A change in the RLO from 0 to 1 at the Start input starts the timer. The programmed time t then elapses regardless of a change in the RLO from 1 to 0 at the Start input.



Checking the signal state of the timer output results in 1 if the time has elapsed.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-13

Timer Instructions



The result of checking the signal state of output Q 4.0 changes to 0 only when the RLO at the Reset input is 1.



If an RLO of 1 is applied to the Reset input, the timer is reset. As long as a signal state of 1 remains at the Start input, a change in the RLO from 1 to 0 at the Reset input has no influence on the timer.



A change in the RLO from 0 to 1 at the Start input with the Reset signal applied causes the timer to start momentarily but to reset immediately because of the Reset statement that follows directly in the program (shown as a pulse line in the timing diagram in Figure 6-10). No checking result is obtained for this pulse, provided that the sequence of writing the statements as they appear above is observed.



When the RLO at the Enable input changes from 0 to 1 while the timer is running and the RLO at the Start input of the timer is 1, the timer is restarted. The time that is programmed is used as the current time for the restart. A change in the RLO from 1 to 0 at the Enable input has no effect on the timer.



The timer is not affected when the RLO at the Enable input changes from 0 to 1 following normal operation of the timer.



When the RLO at the Enable input changes from 0 to 1 while the timer is running and the RLO at the Start input of the timer is 0, the timer is not affected.



If the RLO at the Enable input changes from 0 to 1 when the timer is reset and the RLO at the Start input is still 1, the timer is restarted. The time that is programmed is used as the current time for the restart.



RLO at Enable input







I 2.0


RLO at Start input

I 2.1 

RLO at Reset input



I 2.2

Timer response Check signal state Q 4.0 of timer output.

t

t

t

Load timer: L, LC t = programmed start time Figure 6-11

6-14

Retentive On-Delay Timer Example, Part 2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

Off-Delay Timer: SF

Figures 6-12 and 6-13 provide examples of an off-delay timer. The numbers in squares in the figures are keyed to explanations that follow Figure 6-12. The figures refer to the following STL program:

STL A FR A L SF A R A = L T LC T

Explanation I 2.0 T 1 I 2.1 S5T#0H2M23S0MS T 1 I 2.2 T 1 T 1 Q 4.0 T 1 MW10 T 1 MW12

RLO at Enable input RLO at Start input

I 2.0

Enable timer T 1.

Start timer T 1 as an off-delay timer. Reset timer T 1. Check the signal state of timer T 1.

Load timer T 1.














I 2.1 

RLO at Reset input





I 2.2 

Timer response Check signal state Q 4.0 of timer output.

t



t

Load timer: L, LC t = programmed start time Figure 6-12

Off-Delay Timer Example, Part 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

6-15

Timer Instructions

The following list describes the elements of Figures 6-12 and 6-13:


A change in the RLO from 0 to 1 at the Start input causes a change from 0 to 1 at output Q 4.0 of the timer. A change in the RLO from 1 to 0 at the Start input starts the timer. The programmed time t then elapses.



If an RLO of 1 reappears at the Start input, the timer is reset.



Checking the signal state of output Q 4.0 of the timer results in a signal state of 1 if the RLO at the Start input is 1 and if the time has not yet elapsed.



If an RLO of 1 is applied to the Reset input, the timer is reset. Checking the signal state of the timer then results in 0. A change in RLO from 1 to 0 at the Reset input has no influence on the timer.



A 1 applied to the Reset input while the timer is not running has no effect on the timer.



A change in the RLO from 1 to 0 at the Start input while the Reset signal is applied causes the timer to start momentarily but to reset immediately because of the Reset statement that follows directly in the program (shown as a pulse line in the timing diagram in Figure 6-12). Checking the signal state of the timer then results in 0.



The timer is not affected if the RLO at the Enable input changes from 0 to 1 while the timer is not running. A change in the RLO from 1 to 0 also has no effect on the timer.



If the RLO at the Enable input changes from 0 to 1 while the timer is running, the timer is restarted. The time that is programmed is used as the current time for the restart.

RLO at Enable input

I 2.0

RLO at Start input

I 2.1

RLO at Reset input

I 2.2





Timer response Check signal state of timer output.

t Q 4.0

Load timer: L, LC t = programmed start time Figure 6-13

6-16

Off-Delay Timer Example, Part 2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Timer Instructions

6.5

Address Locations and Ranges for Timer Instructions Tables 6-3 and 6-4 show the address types, address locations, and address ranges for the timer instructions. Table 6-3

Address Locations, Ranges, and Types for Timer Instructions Address Range According to Addressing Type Direct

0 to 255

Table 6-4 Address Symbolic name

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Memory Indirect [DBW] [DIW] [LW] [MW]

0 to 65,534

Timer Address transferred as Parameter Address Parameter Format Time transferred as parameter

6-17

Timer Instructions

6.6

Choosing the Right Timer Figure 6-14 provides an overview of the five types of timers described in Section 6.4. This overview is intended to help you choose the right timer for your timing job.

Input signal

I 2.1

Output signal (Pulse timer)

Q 4.0

SP: t The maximum time that the output signal remains at 1 is the same as the programmed time value t. The output signal stays at 1 for a shorter period if the input signal changes to 0.

Output signal (Extended pulse timer)

Q 4.0

Output signal (On-delay timer)

Q 4.0

SE: t The output signal remains at 1 for the programmed length of time, regardless of how long the input signal stays at 1.

SD: t The output signal changes from 0 to 1 only when the programmed time has elapsed and the input signal is still 1.

Output signal (Retentive on-delay timer)

Q 4.0

Output signal (Off-delay timer)

Q 4.0

SS: t The output signal changes from 0 to 1 only when the programmed time has elapsed, regardless of how long the input signal stays at 1. SF: t The output signal changes from 0 to 1 when the input signal changes from 0 to 1. The output signal remains at 1 for the programmed length of time. The time is started when the input signal changes from 1 to 0.

Figure 6-14

6-18

Choosing the Right Timer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

7

Counter Instructions Chapter Overview

Section

Description

Page

7.1

Overview

7-2

7.2

Setting, Resetting, and Enabling a Counter

7-3

7.3

Couting Up and Counting Down

7-5

7.4

Loading a Count Value as Integer

7-6

7.5

Loading a Count Value in Binary Coded Decimal Format

7-7

7.6

Counter Example

7-8

7.7

Address Locations and Ranges for Counter Instructions

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

7-10

7-1

Counter Instructions

7.1

Overview

Definition

A counter is a function element of the STEP 7 programming language that counts. Counters have an area reserved for them in the memory of your CPU. This memory area reserves one 16-bit word for each counter. The statement list instruction set supports 256 counters. To find out how many counters are available in your CPU, please refer to the CPU technical data. Counter instructions are the only functions with access to the memory area reserved for the counter.

Available Instructions

The statement list representation of the STEP 7 programming language provides the following counter instructions:


Set (S)
Reset (R)
Count up (CU)
Count down (CD)
Enable counter (FR)
Load counter in one of the following formats: – Binary (L) – Binary coded decimal (LC)


Check the signal state of a counter and combine the result in a Boolean logic operation (A, AN, O, ON, X, XN). A signal state check with an A, O or X instruction will have the result “1”, when the value of a counter is greater than “0”. A signal state check with an A, O or X instruction will have the result “0”, when the value of the counter is equal to “0”. Figure 7-1 summarizes the instructions that use a counter word as their address.

Count Up (CU)

Count Down (CD)

Reset a counter (R)

Counter word

Check the signal state of a counter (A, AN, O, ON, X, XN) Figure 7-1

7-2

Set a counter (S)

Enable a counter (FR)

Load a count value (L, LC)

Instructions That Can Use a Counter Word as an Address

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Counter Instructions

7.2

Setting, Resetting, and Enabling a Counter

Description

To set a counter in your statement list program, include three statements to trigger the following operations:


Check a signal state for 0 or 1 (for example, A I 2.3)
Load a count value (for example, L C# 3) into the low word of accumulator 1


Set a counter with the count value you loaded (for example, S C 1). This operation moves the count value from accumulator 1 to the counter word. In your statement list program, a change in the result of logic operation (RLO) from 0 to 1 prior to a Set (S) instruction statement sets a counter to the programmed count value. The programmed count value and the Set statements must follow the logic operation directly that provides the condition for setting the counter.

The Starting Count

You set a counter to a specific value by loading that value into the low word of accumulator 1 and, immediately thereafter, setting that counter. When you set a counter in your program, the CPU looks in accumulator 1 for the count value. Then the CPU transfers the count value from the accumulator to the counter word that you specified in your set statement (for example, S C 1). The range of the count value is 0 to 999.

Example of Setting a Counter

Figure 7-2 provides an example for setting a counter. A change in signal state from 0 to 1 at input I 2.3 sets the counter. The figure refers to the following program:

STL

Explanation

A L

I 2.3 C# 3

S

C 1

Check signal state of input I 2.3. If the signal state is 1, load count value 3 into accumulator 1. Set counter C 1 to a count value of 3. This operation moves the count value of 3 from the accumulator into counter word 1.

Signal state diagram: 1 0 Check I 2.3 for transition 1 0 from 0 to 1. I 2.3

Counter is set to the value given in the load instruction. Figure 7-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Setting a Counter

7-3

Counter Instructions

Resetting a Counter

You reset a counter by using the Reset (R) instruction. The CPU resets a counter when the result of logic operation is 1 immediately before the R instruction in your program. As long as the RLO that comes before an R instruction statement is 1, an A, O, or X instruction that checks the signal state of a counter produces a result of 0 and an AN, ON, or XN instruction that checks the signal state of a counter produces a result of 1. When your program resets a counter, it clears the counter, that is, it resets it to a value of 0. If a counter is to be reset by a static signal at the Reset (R) and independently of the RLO of the other counter instructions, you need to write the Reset statement immediately after the Set, Count Up, or Count Down statement (see Section 7.3) and before the signal check or load operation. Programming for counters should adhere to the following sequence (see also the programming example in Section 7.6): 1. Count up 2. Count down 3. Set counter 4. Reset counter 5. Check signal state of counter 6. Load count value (Read count value)

Enabling a Counter for Restart

A change in the result of logic operation of the Enable instruction (FR) from 0 to 1 enables a counter. The CPU executes the FR instruction only on a positive signal edge. A counter enable is not required to set a counter, nor is it required for normal counting. An enable is only used to set a counter, or to count up or down, if a positive edge (transition from 0 to 1) in front of the corresponding count statement is needed, and if the RLO bit in front of the corresponding statement has a signal state of 1.

7-4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Counter Instructions

7.3

Couting Up and Counting Down

Description of Counting Up

In your statement list program, a change in the result of logic operation from 0 to 1 prior to a Count Up (CU) instruction statement increments the counter. Each time a positive edge change occurs in the RLO directly before a Count Up instruction, the count is incremented by one unit. When the count reaches its upper limit of 999, incrementing stops and any further change in the signal state at the Count Up input have no effect. No provisions are made for overflow (OV).

STL

Explanation

A I 0.1 CU C1

If there is a positive edge change at input I 0.1, counter C 1 is incremented by 1.

Description of Counting Down

In your statement list program, a change in the result of logic operation from 0 to 1 prior to a Count Down (CD) instruction statement decrements the counter. Each time a positive edge change occurs in the RLO directly before a Count Down instruction, the count is decremented by one unit. When the count reaches its lower limit of 0, decrementing stops and any further change in the signal state at the Count Down input have no effect. The counter does not count with negative values.

STL

Explanation

A I 0.2 CD C1

If there is a positive edge change at input I 0.2, counter C 1 is decremented by 1.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

7-5

Counter Instructions

7.4

Loading a Count Value as Integer

Description

A count value is stored in a counter word in binary code. You can use the following instruction to read the binary count value out of a counter word and load it into the low word of accumulator 1: L This type of loading is referred to as loading a counter value directly.

STL

Explanation

L

Load accumulator 1 low directly with the count value of counter C 1 in binary format.

C 1

15 Counter word for C 1

Figure 7-3

Count Value

0

XXXXXX 15

Accumulator 1 low

10 9

10

0

000000

Loading a Count Value into Accumulator 1 Using the L Instruction

You can use the value contained in the accumulator as a result of the L operation for further processing. You cannot transfer a value from the accumulator to the counter word. If you want to start a counter with a specific count value, you need to use the appropriate Set counter statement.

7-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Counter Instructions

7.5

Loading a Count Value in Binary Coded Decimal Format

Description

A count value is stored in a counter word in binary code. You can use the following instruction to read the count value in binary coded decimal (BCD) format out of a counter word and load it into the low word of accumulator 1: LC This type of loading is referred to as loading a count value in BCD format. The value contained in the low word of accumulator 1 as a result of the LC operation has the same format as is needed to set a counter.

STL LC

Explanation C 1

Load accumulator 1 low directly with the count value of counter C 1 in binary coded decimal format.

Counter word for C 1 15 14 13 12

11 10 9

8

7

6

5

4

3

2

1

0

2

1

0

Count value Accumulator 1 low 15 14 13 12

Binary to BCD 11 10 9

8

7

6

5

4

3

0 0 0 0 102 (Hundreds)

101 (Tens)

100 (Ones)

Count in BCD format Figure 7-4

Loading a Count Value into Accumulator 1 Using the LC Instruction

The value contained in the accumulator as a result of the LC operation can be used for further processing, such as transferring the value to the outputs for a display.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

7-7

Counter Instructions

7.6

Counter Example Figure 7-5 provides an example of counting up, counting down, setting and resetting a counter, checking the signal state of a counter, and loading a count value. The example follows the programming sequence recommended in Section 7.2. The numbers in squares in the figure are keyed to explanations that follow the figure. Figure 7-5 refers to the statement list program that follows the explanatory list.

I 2.0 Enable 





I 2.1 Count Up 





I 2.2 Count Down
I 2.3 Set  I 2.4 Reset

Counter Response

ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ

Check signal state of counter output Q 4.0

MW10 Load MW12

Figure 7-5

7-8

3

2

1

0

1

1

1

1

2

1

 3

2

1

0

2

1

Example of Counter Instructions

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Counter Instructions

The following list describes the elements of Figure 7-5:


A change in the RLO from 0 to 1 at the Set input sets the counter to a count value of 3. A transition from 1 to 0 at the Set input has no effect on the counter.



A change in the RLO from 0 to 1 at the Count Down input decreases the counter by one. A transition from 1 to 0 at the Count Down input has no effect on the counter.



The result of the signal state check statement A C 1 is 0 when the count value is 0.



A change in the RLO from 0 to 1 at the Count Up input increases the counter by one. A transition from 1 to 0 at the Count Up input has no effect on the counter.



If an RLO of 1 is applied at the Reset input, the counter is reset. Checking the signal state produces a result of 0. A change in the RLO from 1 to 0 at the Reset input has no effect on the counter.



A change in the RLO from 0 to 1 at the Count Up input while the Reset signal is applied causes the counter to increase momentarily but to reset immediately because of the Reset statement that follows directly in the program. (The momentary increase is indicated by a pulse line in the timing diagram in Figure 7-5). Checking the signal state then produces a result of 0.



A change in the RLO from 0 to 1 at the Enable input with Count Up and Count Down applied causes the counter to increase momentarily but then decrease immediately because of the Count Down statement that follows directly in the program. (The momentary increase is indicated by a pulse line in the timing diagram in Figure 7-5). A transition from 1 to 0 at the Enable input has no effect on the counter.

STL A FR A CU A CD A L S A R A = L T LC T

Explanation I 2.0 C 1 I 2.1 C 1 I 2.2 C 1 I 2.3 C# 3 C 1 I 2.4 C 1 C 1 Q 4.0 C 1 MW10 C 1 MW12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Enable counter C 1. Count up (increment by 1). Count down (decrement by 1).

Set counter C 1. Reset counter C. Check the signal state of counter C 1. Load counter C 1 (binary coded)

Load counter C 1 (BCD coded).

7-9

Counter Instructions

7.7

Address Locations and Ranges for Counter Instructions Table 7-1 shows the address types, address locations, and address ranges for the counter instructions. Table 7-1

Address Locations, Ranges, and Types for Counter Instructions Address Range according to Addressing Type Direct

0 to 65,535

7-10

Memory Indirect [DBW] [DIW] [LW] [MW]

0 to 65,534

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

8

Chapter Overview

Page

Section

Description

8.1

Overview

8-2

8.2

Loading and Transferring

8-3

8.3

Reading the Status Word or Transferring to the Status Word

8-6

8.4

Loading Times and Counts as Integers

8-7

8.5

Loading Times and Counts in Binary Coded Decimal Format

8-9

8.6

Loading and Transferring between Address Registers

8-11

8.7

Loading Data Block Information

8-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

8-1

Load and Transfer Instructions

8.1

Overview

Definition

The Load (L) and Transfer (T) instructions enable you to program an interchange of information between input or output modules and memory areas, or between memory areas. The CPU executes these instructions in each scan cycle as unconditional instructions, that is, they are not affected by the result of logic operation of a statement.

Information Interchange

The L and T instructions enable an interchange of information between the following modules or memory areas:


Input and output modules and the following areas of memory: – Process-image input and output tables – Bit memory – Timers and counters – Data areas


Process-image input and output tables and the following areas of memory: – Bit memory – Timers and counters – Data areas


Timers and counters and the following areas of memory: – Process-image input and output tables – Bit memory – Data areas

Method of Interchange

The L and T instructions provide information exchange via the accumulator. An L instruction statement writes (loads) the contents of its addressed source location into accumulator 1, shifting any information already contained there to accumulator 2. The old contents of accumulator 2 is overwritten. A T instruction statement copies the contents of accumulator 1 and writes them into the memory of its addressed destination. Because the T instruction only copies the information that is in accumulator 1, this information is still available to other instructions. The L and T instructions can handle information in bytes (8 bits), words (16 bits), and double words (32 bits). The accumulator has a total of 32 bits. Data with fewer than 32 bits is right justified in the accumulator. The remaining bits of the accumulator are padded with zeros. LOAD Source

31

16 15

0

TRANSFER Destination

Accumulator 1

8-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

8.2

Loading and Transferring

Description

You can use the Load (L) or Transfer (T) instruction to transfer information to or from accumulator 1 in chunks of the following sizes:
Byte (B, 8 bits)
Word (W, 16 bits)
Double word (D, 32 bits) A byte is loaded into the low byte of the low word of accumulator 1. A word is loaded into the low word of accumulator 1. Unused bytes are reset to 0 when loading into the accumulator.

Immediate Addressing

Table 8-1

The L instruction can address constants of 8, 16, and 32 bits as well as ASCII characters. This type of addressing is called immediate addressing (see Section 3.1 and Table 8-1). Addresses of L Instructions: Immediate Addressing Example

Address

Explanation


..

L

+5

Loads a 16-bit integer constant into accumulator 1.

B#(..,..)

L

B#(1,10)

L

B#(1,10,5,4)

Loads a contact as 2 bytes into accumulator 1. (In this example, the 10 goes into the low byte of the low word of accumulator 1; the 1 goes into the high byte of the low word of accumulator 1, see Figure 2-4.) Loads a contact as 4 bytes into accumulator 1. (In this example, the 4 and the 5 go into the low and high byte of the low word of accumulator 1, respectively; the 10 and the 1 go into the low and high byte of the high word of accumulator 1, respectively, see Figure 2-4.)

L#..

L

L#+5

Loads a 32-bit integer constant into accumulator 1.

16#..

L L L

B#16#EF W#16#FAFB DW#16#1FFE_1ABC

Loads an 8-bit hexadecimal constant into accumulator 1. Loads a 16-bit hexadecimal constant into accumulator 1. Loads a 32-bit hexadecimal constant into accumulator 1.

2#..

L L

2#1111_0000_1111_0000 2#1111_0000_1111_0000_ 1111_0000_1111_0000

Loads a 16-bit binary constant into accumulator 1. Loads a 32-bit binary constant into accumulator 1.

’..’

L L

’AB’ ’ABCD’

Loads 2 characters into accumulator 1. Loads 4 characters into accumulator 1.

C#..

L

C#1000

Loads a 16-bit count constant into accumulator 1.

S5TIME#..

L

S5TIME#2S

Loads a 16-bit S5TIME constant into accumulator 1.

..

L

1.0E+5

Loads a 32-bit IEEE floating point into accumulator 1.

P#..

L L

P#I1.0 P##Start

L

P#ANNA

Loads a 32-bit pointer into accumulator 1. Loads a 32-bit pointer to a local variable (Start) into accumulator 1 Loads a pointer to a specified parameter in accumulator 1. (This instruction loads the relative address offset of the specified parameter. In order to determine the absolute offset in the instance data block of a function block with multiple instances, the contents of the AR2 register must be added to this value.)

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

8-3

Load and Transfer Instructions

Table 8-1

, continuedAddresses of L Instructions: Immediate Addressing, continued

Address

Example

Explanation

D#..

L

D#1994-3-15

Loads a 16-bit date into accumulator 1.

T#..

L

T#0D_1H_1M_0S_0MS

Loads a 32-bit time value into accumulator 1.

TOD#..

L

TOD#1:10:3.3

Loads a 32-bit time-of-day value into accumulator 1.

Direct and Indirect Addressing

The L and T instructions can address a byte (B), word (W), or double word (D) in the following memory areas using direct and indirect addressing (see also Sections 3.2, 3.3, and 3.5):


Process-image input and output (address identifiers IB, IW, I, QB, QW, QD)


External inputs and outputs (address identifiers PIB, PIW, PID, PQB, PQW, PQD). External inputs can be addresses of L instructions only; external outputs can be addresses of T instructions only.


Bit memory (address identifiers MB, MW, MD)
Data block (address identifiers DBB, DBW, DBD, DIB, DIW, DID)
Local data (temporary local data, address identifiers LB, LW, LD) Table 8-2 lists the addresses for L and T instructions that use direct and indirect addressing. Table 8-2 Address ID IB IW ID

Maximum Address Range according to Addressing Type Direct 0 to 65,535 0 to 65,534 0 to 65,532

QB QW QD

0 to 65,535 0 to 65,534 0 to 65,532

PIB PIW PID (L only)

0 to 65,535 0 to 65,534 0 to 65,532

PQB PQW PQD (T only)

8-4

Addresses of L and T Instructions: Direct and Indirect Addressing

0 to 65,535 0 to 65,534 0 to 65,532

Memory Indirect

Area-Internal Register Indirect

[DBD] [DID] [LD] [MD]

0 to 65,532

[DBD] [DID] [LD] [MD]

0 to 65,532

[AR1, P#byte.bit] 0 to 8,191 [AR2, P#byte.bit]

[AR1, P#byte.bit] 0 to 8,191 [AR2, P#byte.bit]

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

Table 8-2 Address ID

Area-Crossing Indirect Addressing

Addresses of L and T Instructions: Direct and Indirect Addressing Direct

MB MW MD

0 to 255 0 to 254 0 to 252

DBB DBW DBD

0 to 65,535 0 to 65,534 0 to 65,532

DIB DIW DID

0 to 65,535 0 to 65,534 0 to 65,532

LB LW LD

0 to 65,535 0 to 65,534 0 to 65,532

Memory Indirect [DBD] [DID] [LD] [MD]

0 to 65,532

[DBD] [DID] [LD] [MD]

0 to 65,532

[AR1, P#byte.bit] 0 to 8,191 [AR2, P#byte.bit]

[AR1, P#byte.bit] 0 to 8,191 [AR2, P#byte.bit]

The L and T instructions can address a byte (B), word (W), or double word (D) using area-crossing register indirect addressing (see Section 3.6). Table 8-3

Addresses of L and T Instructions: Area-Crossing Register Indirect Addressing Address Identifier1

B (byte), W (word), D (double word) 1

Byte, Word, or Double Word as Parameter

Area-Internal Register Indirect

Address Range [AR1, P#byte.bit] [AR2, P#byte.bit]

0 to 8,191

The memory area is encoded in bits 24 through 31 of AR1 or AR2 (see Section 3.6).

For their address, the L and T instructions can also use a byte, word, or double word that is transferred as parameter. Table 8-4

Address of L and T Instructions: Byte, Word, or Double Word Transferred as Parameter

Address Symbolic name

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Address Parameter Format A byte, word, or double word transferred as parameter

8-5

Load and Transfer Instructions

8.3

Reading the Status Word or Transferring to the Status Word

Loading the Status Word

You can use the Load (L) instruction to load bits 0 through 8 of the status word (see Figure 8-1) into accumulator 1. Bits 9 through 31 of accumulator 1 are reset to 0. The instruction statement is shown in the example that follows Figure 8-1. Note For the S7-300 series CPUs, the statement L STW does not load the FC, STA, and OR bits of the status word. Only bits 1, 4, 5, 6, 7, and 8 are loaded into the corresponding bit positions of the low word of accumulator 1.

215...

Figure 8-1

...29

28

27

26

BR

CC 1 CC 0

25 OV

24 OS

23

22

21

20

OR

STA

RLO FC

Structure of the Status Word

STL

Explanation

L

Loads bits 0 to 8 of the status word into the low word of accumulator 1.

STW

Transferring to the Status Word

You can use the Transfer (T) instruction to transfer the contents of accumulator 1 to the status word (see Figure 8-1). The instruction statement is shown in the following program excerpt.

STL

Explanation

T

Transfers the contents of accumulator 1 to the status word.

8-6

STW

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

8.4

Loading Times and Counts as Integers

Loading a Time

A time value is stored in a timer word in binary code. You can use the following Load (L) instruction to read the binary time value out of a timer word and load it into the low word of accumulator 1: L This type of loading is referred to as loading of a time value directly. The time value in the timer word is decremented from its starting value to 0 during the processing of the user program in the CPU. When you use the L instruction with a timer word as address, you get a value that lies between the starting time of the timer word and 0. The time that elapses from the moment a timer starts is calculated from the difference of the start time and the time being read currently.

STL

Explanation

L

Load accumulator 1 low directly with the time of timer T 1 in binary code.

T 1

15

10 9

15

10 9

0000

00

Time

0

Timer word

Accumulator 1 low

Figure 8-2

0

Loading a Time Value into Accumulator 1 Using the L Instruction

You can use the value contained in the accumulator as a result of the L operation for further processing. You cannot transfer a value from the accumulator to the timer word. Note When you use the L instruction to read out a timer word, you get a value between 0 and 999. You do not get the time base that was loaded with the time value.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

8-7

Load and Transfer Instructions

Loading a Count

A count value is stored in a counter word in binary code. You can use the following Load (L) instruction to read the binary count value out of a counter word and load it into the low word of accumulator 1: L This type of loading is referred to as loading a counter value directly.

STL

Explanation

L

Load accumulator 1 low directly with the count value of counter C 1 in binary format.

C 1

15 Counter word for C 1

Figure 8-3

Count Value

0

XXXXXX 15

Accumulator 1 low

10 9

10

0

000000

Loading a Count Value into Accumulator 1 Using the L Instruction

You can use the value contained in the accumulator as a result of the L operation for further processing. You cannot transfer a value from the accumulator to the counter word. If you want to start a counter with a specific count value, you need to use the appropriate Set counter statement (see Section 7.2).

8-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

8.5

Loading Times and Counts in Binary Coded Decimal Format

Loading a Time in BCD Format

A time value is stored in a timer word in binary code. You can use the following Load (L) instruction to read the time value in binary coded decimal (BCD) format out of a timer word and load it into the low word of accumulator 1: LC In addition to the time value, the time base is also loaded. The value which appears in the low word of Accumulator 1 as the result the LC instruction, has the format which is required to start a time. This type of loading is referred to as loading a time in BCD format. The time value in the timer word is decremented from its start value to 0. When you use the LC instruction with a timer word as address, you get a value that lies between the starting time of the timer word and 0. The time that elapses from the moment a timer starts is calculated from the difference of the start time and the time currentlybeing read.

STL LC

Explanation T 1

Load accumulator 1 low with the time and time base of timer T 1 in BCD format.

15 14 13 12 11 10 9

Time

0

Timer word Time base

Binary to BCD

15 14 13 12 11 Accumulator 1 low

0 0 Time base

Figure 8-4

0

102 (Hundreds)

101 (Tens)

100 (Ones)

Loading a Count Value into Accumulator 1 Using the L Instruction

The value contained in the accumulator as a result of the LC operation can be used for further processing, such as transferring the value to the outputs for a display. You cannot transfer a value from the accumulator to the timer word.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

8-9

Load and Transfer Instructions

Loading a Count in BCD Format

A count value is stored in a counter word in binary code. You can use the following Load (L) instruction to read the count value in binary coded decimal (BCD) format out of a counter word and load it into the low word of accumulator 1: LC This type of loading is referred to as loading a count value in BCD format. The value contained in the low word of accumulator 1 as a result of the LC operation has the same format as is needed to set a counter. A count value is stored in a counter word in binary code. You can load the time value into the low word of accumulator 1 in binary coded decimal format (BCD format, see Figure 8-5). You can use the LC instruction to read out a count value in BCD format.

STL LC

Explanation Load accumulator 1 low directly with the count value of counter C 1 in binary coded decimal format.

C 1

15 14 13 Counter word for C 1

X

X

X

12 11 10 9 X

X

8

7

6

5

4

3

2

1

0

2

1

0

X

Count value Binary to BCD 15 14 13 12 Accumulator 1 low

0

0

0

11 10 9

8

7

6

5

4

3

0 102 (Hundreds)

101 (Tens)

100 (Ones)

Count in BCD format

Figure 8-5

Loading a Count Value into Accumulator 1 Using the LC Innstruction

The value contained in the accumulator as a result of the LC operation can be used for further processing, such as transferring the value to the outputs for a display. You cannot transfer a value from the accumulator to the counter word.

8-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Load and Transfer Instructions

8.6

Loading and Transferring between Address Registers

Description

Your program can use the following instructions to enable the CPU to exchange information between address registers or exchange the contents of the two registers: Instruction

Immediate Addressing

Explanation

LAR1

Loads address register 1 with the contents of the area that the instruction addresses. If no address is indicated, LAR1 loads address register 1 with the contents of accumulator 1. LAR1 can also use AR2 as an address, that is LAR1 can load AR1 with the contents of AR2.

LAR2

Loads address register 2 with the contents of the area that the instruction addresses. If no address is indicated, LAR2 loads address register 2 with the contents of accumulator 1.

TAR1

Transfers the contents of address register 1 into the destination that the instruction addresses. If no address is indicated, TAR1 transfers the contents of address register 1 to accumulator 1. TAR1 can also use AR2 as an address, that is, TAR1 can transfer the contents of AR1 into AR2.

TAR2

Transfers the contents of address register 2 into the destination that the instruction addresses. If no address is indicated, TAR2 transfers the contents of address register 2 to accumulator 1.

TAR

Exchanges the contents of AR1 and AR2.

The LAR1 and LAR2 instructions can address constants of 32 bits. This type of addressing is called immediate addressing (see Section 3.1). The immediate address is used to load a 32-bit pointer immediately into the address register (see Table 8-5). LAR1 P#{area,} Byte{.Bit} with {area} = {I, Q, M, D, DX, L} Byte = 0 to 65,535 {.Bit} = 0 to 7 Table 8-5

LAR1 and LAR2: Immediate Addressing Example

Description

LAR1

P#I0.0

Loads the area-crossing pointer P#I0.0 into address register 1

LAR2

P#0.0

Loads the area-internal pointer with the location 0 into address register 2

LAR1

P##Start

Loads an area-crossing pointer to the local variable (Start) into address register 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

8-11

Load and Transfer Instructions

Direct Addressing

You can use direct addressing with LAR1, LAR2, TAR1, and TAR2. Table 8-6 Instruction

1 2

8.7

LAR1, LAR2, TAR1, TAR2: Direct Addressing Register As Address

LAR1

{BLANK}1)

LAR2

{BLANK}1

TAR1

{BLANK}2) or AR2

TAR2

{BLANK}2)

or AR2

Address Identifier and Range DBD DID LD MD

532 0 to 65 65,532

DBD DID LD MD

0 to 65,532

{BLANK} If no address is indicated, LAR1/LAR2 loads the address register with the contents of accumulator 1. {BLANK} If no address is indicated, TAR1/TAR2 transfers the contents of the address register to accumulator 1.

Loading Data Block Information You can use the Load (L) instruction to load the length or number of a data block into accumulator 1. Table 8-7 summarizes the addresses for this type of loading. For more information on on loading the length or number of a data block into accumulator 1 see Section 15.3. Table 8-7 Address

8-12

Loading the Length or Number of a Data Block into Accumulator 1 Explanation

DBLG

Loads the length in bytes of a shared data block into accumulator 1

DILG

Loads the length in bytes of an instance data block into accumulator 1

DBNO

Loads the number of a shared data block into accumulator 1

DINO

Loads the number of an instance data block into accumulator 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

9

Integer Math Instructions Chapter Overview

Section

Description

Page

9.1

Four-Function Math

9-2

9.2

Adding an Integer to Accumulator 1

9-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

9-1

Integer Math Instructions

9.1

Four-Function Math

Description

Table 9-1 lists the statement list instructions that you can use to add, subtract, multiply, and divide integers (16 bits) and double integers (32 bits). Table 9-1

Relationship of Math Operators to Accumulators

Four-Function Math Instructions for Integers and Double Integers

Instruction

Size in Bits

Function

+I

16

Adds the contents of the low words of accumulators 1 and 2 and stores the result in the low word of accumulator 1.

–I

16

Subtracts the contents of the low word of accumulator 1 from the contents of the low word of accumulator 2 and stores the result in the low word of accumulator 1.

I

16

Multiplies the contents of the low words of accumulators 1 and 2 and stores the result (32 bits) in accumulator 1.

/I

16

Divides the contents of the low word of accumulator 2 by the contents of the low word of accumulator 1. The result is stored in the low word of accumulator 1. Any whole remainder is stored in the high word of accumulator 1.

+D

32

Adds the contents of accumulators 1 and 2 and stores the result in accumulator 1.

–D

32

Subtracts the contents of accumulator 1 from the contents of accumulator 2 and stores the result in accumulator 1.

D

32

Multiplies accumulator 1 by the contents of accumulator 2 and stores the result in accumulator 1.

/D

32

Divides the contents of accumulator 2 by the contents of accumulator 1. The result is stored in accumulator 1.

MOD

32

Divides the contents of accumulator 2 by the contents of accumulator 1 and stores the remainder as a result in accumulator 1.

The function descriptions in Table 9-1 point out that the math operations combine the contents of accumulators 1 and 2. The result is stored in accumulator 1. The old contents of accumulator 1 is shifted to accumulator 2. The contents of accumulator 2 remains unchanged. In the case of CPUs with four accumulators, the contents of accumulator 3 is then copied into accumulator 2 and the contents of accumulator 4 into accumulator 3. The old contents of accumulator 4 remains unchanged.

9-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Integer Math Instructions

Combining two Integers (16 bits) in CPUs with two Accumulators

The Add Accumulators 1 and 2 As Integer instruction (+I) tells the CPU to add the contents of the low word of accumulator 1 and the low word of accumulator 2 and store the result in the low word of accumulator 1. This operation overwrites the old contents of the low word of accumulator 1. The old contents of accumulator 2 and the high word of accumulator 1 remain unchanged (see Figure 9-1). A sample program follows the figure. Accumulator contents before math operation

Accumulator contents after math operation

Accumulator 2

Accumulator 2

31

16 15

IV

0

III

IV

Accumulator 1 31

II

Figure 9-1

Combining two Integers (16 bits) in CPUs with four Accumulators

+I

16 15

III

Accumulator 1

0

II

I

III + I

Adding Two Integers

The Add Accumulators 1 and 2 As Integer instruction (+I) tells the CPU to add the contents of the low word of accumulator 1 and the low word of accumulator 2 and store the result in the low word of accumulator 1. This operation overwrites the old contents of the low word of accumulator 1. It then copies the contents of accumulator 3 to accumulator 2 and the contents of accumulator 4 to accumulator 3. Accumulator 4 and the high word of accumulator 1 remain unchanged (see Figure 9-2).

Accumulator contents before math operation

Accumulator contents after math operation

Accumulator 4

Accumulator 4

31

16 15

VIII

0

VII

VIII

Accumulator 3 31

Accumulator 3

16 15

VI

0

V

VIII

Accumulator 2 31

0

III

VI

Accumulator 1 31

Figure 9-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

+I

16 15

II

VII

Accumulator 2

16 15

IV

VII

V

Accumulator 1

0

I

II

III + I

Adding two Integers in CPUs with four Accumulators

9-3

Integer Math Instructions

STL

Explanation

L

MW10

L

DBW12

Load the value of memory word MW10 into accumulator 1. Load the value of data word DBW12 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. The CPU interprets the contents of the low words of accumulators 1 and 2 as 16-bit integers, adds them, and stores the result in the low word of accumulator 1. Transfer the contents of the low word of accumulator 1 (the result) to data word DBW14.

+I

T

DBW14

Evaluating the Bits in the Status Word

The math instructions affect the following bits of the status word:


CC 1 and CC 0
OV
OS

Valid Result

A hyphen (–) entered in a bit column of the table means that the bit in question is not affected by the result of the integer math operation. You can use the instructions in Table 9-5 to evaluate these bits of the status word Table 9-2

Signal State of Bits in the Status Word for Integer Math Result in Valid Range

Bits of Status Word Valid Range g for an Integer g (16 Bits) and Double Integer (32 Bits) Result CC 1 CC 0 OV OS 0 (zero)

0

0

0

–

I: -32,768 v Result t 0 (negative number) D: -2,147,483,648 v Result t 0 (negative number)

0

1

0

–

I: 32,767 w Result u0 (positive number) D 2,147,483,647 w Result u0 (positive number)

1

0

0

–

Table 9-3

Invalid Result

Range g Not Valid for a Double Integer g Result (32 Bits) I: Result u D: Result u

9-4

Signal State of Bits in the Status Word for Integer Math Result That Is Not in Valid Range Bits of Status Word CC 1 CC 0

OV

OS

32,767 (positive number) 2,147,483,647 (positive number)

1

0

1

1

I: t –32,768 (negative number) D: Result t -2,147,483,648 (negative number)

0

1

1

1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Integer Math Instructions

Table 9-4

Signal State of Bits in the Status Word for Double Integer Math Instructions +D, /D, and MOD Bits of Status Word Instruction Instruct on

CC 1 CC 0

OV

OS

+D: Result = -4,294,967,296

0

0

1

1

/D or MOD: Division by 0 has occurred.

1

1

1

1

Table 9-5

Instructions That Evaluate the CC 1, CC 0, OV, and OS Bits

Instruction

A,O,X,AN,ON,XN

Reference to Bit of the Status Word or Jump Label

Bits in Status Word That Are Evaluated (indicated by an X)

>0, <0, <>0, >=0, <=0, CC 1, CC 0, OV, OS ==0, UO, OV, OS

Section in This Manual 5.3

JO

<jump label>

OV

16.4

JOS

<jump label>

OS

16.4

JUO

<jump label>

CC 1 and CC 0

16.5

JZ

<jump label>

CC 1 and CC 0

16.5

JN

<jump label>

CC 1 and CC 0

16.5

JP

<jump label>

CC 1 and CC 0

16.5

JM

<jump label>

CC 1 and CC 0

16.5

JMZ

<jump label>

CC 1 and CC 0

16.5

JPZ

<jump label>

CC 1 and CC 0

16.5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

9-5

Integer Math Instructions

9.2

Adding an Integer to Accumulator 1

Add 16 and 32-Bit Integer Constants

Table 9-6

You can use the Add Integer Constant instruction to add an integer constant to the contents of the low word of accumulator 1. Table 9-6 lists the possibilities. These instructions do not affect the status word bits.

Adding an Integer to Accumulator 1

Instruction

Address

Function

+

+ integer

Adds a 16-bit integer constant to the contents of the low word of accumulator 1. The result is stored in accumulator 1. The old contents of the low word of this accumulator are overwritten. Accumulator 2 and the high word of accumulator 1 remain unchanged.

+

+ L#double integer

Adds a 32-bit integer constant to the contents of accumulator 1. The result is stored in accumulator 1. The old contents of this accumulator are overwritten. Accumulator 2 remains unchanged.

Examples

Below are two programs with Add Integer Constant instructions.

STL

Explanation

L L +I + T

Load the value in MW10 into accumulator 1. Load the value in MW20 into accumulator 1. Add the 16-bit values in accumulator 1 and 2. Add a minus 5 to the result of the +I statement. Transfer the new result to MW14.

MW10 MW20 –5 MW14

STL

Explanation

L L +D + T

Load the value in MD10 into accumulator 1. Load the value in MD16 into accumulator 1. Add the 32-bit values in accumulator 1 and 2. Add a minus 1 to the result of the +D statement. Transfer the new result to MD24.

9-6

MD10 MD16 L#–1 MD24

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions Chapter Overview

Section

10

Description

Page

10.1

Four-Function Math

10-2

10.2

Forming the Absolute Value of a Floating-Point Number

10-6

10.3

Extended Math Instructions

10-7

10.4

Forming the Square / Square Root of a Floating-Point Number

10-9

10.5

Forming the Natural Logarithm of a Floating-Point Number

10-11

10.6

Forming the Exponential Value of a Floating-Point Number

10-12

10.7

Forming Trigonometric Functions on Angles Acting as Floating-Point Numbers

10-13

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-1

Floating-Point Math Instructions

10.1 Four-Function Math

Description

Table 10-1 lists the statement list instructions that you can use to add, subtract, multiply, and divide 32-bit IEEE floating-point numbers. Because IEE 32-bit floating-point numbers belong to the data type called “REAL”, the mnemonic abbreviation for these instructions is R. Table 10-1

Instruction

Relationship of Math Instructions to Accumulators

Four-Function Math Instructions for IEEE 32-Bit Floating-Point Numbers Function

+R

Adds the IEEE 32-bit floating-point numbers in accumulators 1 and 2 and stores the 32-bit result in accumulator 1.

-R

Subtracts the IEEE 32-bit floating-point number in accumulator 1 from the IEEE 32-bit floating-point number in accumulator 2 and stores the 32-bit result in accumulator 1.

R

Multiplies the IEEE 32-bit floating-point number in accumulator 1 by the IEEE 32-bit floating-point number in accumulator 2 and stores the 32-bit result in accumulator 1.

/R

Divides the IEEE 32-bit floating-point number in accumulator 2 by the IEEE 32-bit floating-point number in accumulator 1. The 32-bit result is stored in accumulator 1.

The function descriptions in Table 10-1 point out that the math instructions combine the contents of accumulators 1 and 2. The result is stored in accumulator 1. The old contents of accumulator 1 is shifted to accumulator 2. The contents of accumulator 2 remains unchanged. In the case of CPUs with four accumulators, the contents of accumulator 3 is copied into accumulator 2 and the contents of accumulator 4 into accumulator 3. The old contents of accumulator 4 remains unchanged.

10-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

Result of Combining Two Integers in CPUs with Two Accumulators

The Add Accumulators 1 and 2 As Real instruction (+R) tells the CPU to add the contents of accumulator 1 and accumulator 2 and store the result in accumulator 1. This operation overwrites the old contents of accumulator 1. The old contents of accumulator 2 remain unchanged (see Figure 10-1). A sample program follows Figure 10-2.

Accumulator contents before math operation Accumulator 2 31

16 15

Accumulator contents after math operation Accumulator 2

0

II

II

Accumulator 1 31

+R

16 15

Accumulator 1

0

II + I

I

Figure 10-1

Adding Two IEEE Floating-Point Numbers

The same pattern applies to the remaining floating-point math instructions. Table 10-2

Instruction

Result of Instructions with Denormalized Numbers in CPUs with Two Accumulators Input Value Result Accumulator 1 Accumulator 2 Accumulator 1 Accumulator 2

+R

a

b

a

b

-R

a

b

-a

b

*R

a

b

0

b

+R

a

b

FFFF

b

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-3

Floating-Point Math Instructions

Result of Combining Two Integers in CPUs with Two Accumulators

The Add Accumulators 1 and 2 As Real instruction (+R) tells the CPU to add the contents of accumulator 1 and accumulator 2 and store the result in accumulator 1. This instruction overwrites the old contents of accumulator 1. Next the contents of accumulator 3 is copied into accumulator 2 and the contents of accumulator 4 is copied into accumulator 3 (see Figure 10-2). Accumulator contents before math instruction

Accumulator contents after math instruction

Accumulator 4

Accumulator 4

31

16 15

0

IV

IV Accumulator 3

Accumulator 3 31

16 15

0

III

IV

Accumulator 2 31

16 15

Accumulator 2 0

II

II

Accumulator 1 31

16 15

I Figure 10-2

+R

Accumulator 1

0

II + I

Adding Two IEEE Floating-Point Numbers in CPUs with four Accumulators

The same pattern applies to the remaining floating-point math instructions. Example STL L L

Explanation MD100 DBD4

+R

T

DBD16

Bits Affected by the Math Instructions

Load the value in memory double word MD100 into accumulator 1. Load the value in data double word DBD4 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. (The values in these double words must be in floating-point format.) The CPU interprets the contents of accumulators 1 and 2 as 32-bit IEEE floating-point numbers, adds them, and stores the result in accumulator 1. Transfer the contents of accumulator 1 (the result) to data double word DBD16. (DBD16 = MD100 + DBD4)

The math instructions do affect the following bits of the status word:
CC 1 and CC 0
OV
OS You can use the instructions in Table 10-5 to evaluate these bits of the status word. Table 10-3 shows the signal states of the status word bits for floating-point math results that fall within the valid range. A hyphen (–) entered in a bit column of the table means that the bit in question is not affected by the result of the floating-point math instruction.

10-4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

Table 10-3

Signal State of Bits in the Status Word for Floating-Point Math Result in Valid Range Bits of Status Word

Valid Val d Range for a Float Floating ng-Po Point nt Result (32 B Bits) ts)

CC 1 CC 0

OV

OS

+0, -0 (zero)

0

0

0

–

-3.402823E+38 t Result t -1.175494E–38 (negative number)

0

1

0

–

+1.175494E–38 t Result t 3.402823E+38 (positive number)

1

0

0

–

Table 10-4

Signal State of Bits in the Status Word for Floating-Point Math Result That Is Not in Valid Range Bits of Status Word

g Not Valid for a Floating-Point g Range Result (32 Bits)

CC 1 CC 0

OV

OS

-1.175494E–38 t Result t -1.401298E–45 (negative number) Underflow

0

0

1

1

+1.401298E–45 t Result t +1.175494E–38 (positive number) Underflow

0

0

1

1

Result t -3.402823E+38 (negative number) Overflow

0

1

1

1

Result u -3.402823E+38 (positive number) Overflow

1

0

1

1

Table 10-5

Instructions That Evaluate the CC 1, CC 0, OV, and OS Bits of the Status Word

Instruction

A,O,X,AN,ON,XN

Reference to Bit of Status Word or Jump Label

Bits in Status Word That Are Evaluated (indicate d by an X)

>0, <0, <>0, >=0, <=0, CC 1, CC 0, OV, OS ==0, UO, OV, OS

Section in This Manual 5.3

JO

<jump label>

OV

16.4

JOS

<jump label>

OS

16.4

JUO

<jump label>

CC 1 and CC 0

16.4

JZ

<jump label>

CC 1 and CC 0

16.5

JN

<jump label>

CC 1 and CC 0

16.5

JP

<jump label>

CC 1 and CC 0

16.5

JM

<jump label>

CC 1 and CC 0

16.5

JMZ

<jump label>

CC 1 and CC 0

16.5

JPZ

<jump label>

CC 1 and CC 0

16.5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-5

Floating-Point Math Instructions

10.2 Forming the Absolute Value of a Floating-Point Number

Description

You can use the Absolute Value of a Real instruction (ABS) to form the absolute value of an IEEE 32-bit floating-point number in accumulator 1. An absolute value is a non-negative number equal in numerical value to a given real number. For an absolute value, a sign (+ or -) is not relevant. For example, 5 is the absolute value of +5 or -5.

Example

The following program provides an example of the ABS instruction:

STL

Explanation

L

DBD0

L

+12.3E+00

Load the value in data double word DBD0 into accumulator 1. Load the value +12.3E+00 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. The CPU divides the contents of accumulator 2 by the contents of accumulator 1 and stores the result in accumulator 1. Transfer the contents of accumulator 1 (the result) to memory double word MD20. (MD20 = DBD0 / 12.3) Negate the IEEE floating-point number in accumulator 1 (see Section 12.4). Transfer the result from accumulator 1 to memory double word MD24. (MD24 = [–1]  MD20) The CPU forms the absolute value of the IEEE floating-point number in accumulator 1. Transfer the absolute value from accumulator 1 to memory double word MD28. (MD28 = ABS[MD20])

/R

T

MD20

NEGR T MD24 ABS T

MD28

10-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

10.3 Extended Math Instructions

Description

Table 10-6 lists the STL instructions which can be used for extended math instructions on floating-point numbers.

ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Table 10-6

Relationship of Extended Math Instructions to Accumulators

Extended Math Instructions for IEEE 32-Bit Floating-Point Numbers

Instruction

Function

SQRT

Calculates the square root of the 32 bit IEEE floating-point number in ACCU1 and stores the 32 bit result in ACCU1.

SQR

Calculates the square of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

LN

Calculates the natural logarithm of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

EXP

Calculates the exponential value of the 32 bit IEEE floating-point number to base E and stores the 32-bit result in ACCU1.

SIN

Calculates the sine of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

COS

Calculates the cosine of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

TAN

Calculates the tangent of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

ASIN

Calculates the arc sine of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

ACOS

Calculates the arc cosine of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

ATAN

Calculates the arc tangent of the 32 bit IEEE floating-point number in ACCU1 and stores the 32-bit result in ACCU1.

The extended math instructions only work in conjunction with accumulator 1. The value to which the operation is applied is expected in accumulator 1. The result is stored in accumulator 1; the old contents of accumulator 1 is overwritten. The contents of accumulator 2, accumulator 3 and accumulator 4 remain unchanged.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-7

Floating-Point Math Instructions

Effect of Extended Math Instructions on the Bits in the Status Word

The CPU executes the four-function math instructions listed in Table 10-1, without regard to, and without affecting the result of logic operation. The extended math instructions do affect the following bits of the status word:


CC 1 and CC 0
OV
OS To evaluate these bits, you can use the instructions in Table 10-7 (Section 10.1) and see Section 5.3. Table 10-7

Extended Math Instructions for 32-Bit IEEE Floating-Point Numbers

ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ ÁÁÁÁÁÁ ÁÁÁÁÁ Instruction

Reference to Bit of Bits in Status Word Status Word or Jump That Are Evaluated Label (indicated by an X)

A, O, X, AN, ON, XN >0, <0, <>0, >=0, <=0, ==0, UO, OV, OS

10-8

Section in This Manual

CC 1, CC 0, OV, OS

5.3

JO

<jump label>

OV

16.4

JOS

<jump label>

OS

16.4

JUO

<jump label>

CC 1 and CC 0

16.4

JZ

<jump label>

CC 1 and CC 0

16.5

JN

<jump label>

CC 1 and CC 0

16.5

JP

<jump label>

CC 1 and CC 0

16.5

JM

<jump label>

CC 1 and CC 0

16.5

JMZ

<jump label>

CC 1 and CC 0

16.5

JPZ

<jump label>

CC 1 and CC 0

16.5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

10.4 Forming the Square / Square Root of a Floating-Point Number

Description

The instruction SQR (square) calculates the square of the 32 bit IEEE floating-point number in accumulator 1 and stores the 32-bit result in accumulator 1. The operation SQR overwrites the old contents of accumulator 1; the contents of accumulator 2, accumulator 3, and accumulator 4 remain unchanged. The instruction SQRT (square root) calculates the square root of the 32 bit IEEE floating-point number in accumulator 1 and stores the 32-bit result in accumulator 1. The input value must be greater or equal to zero. The instruction SQRT overwrites the old contents of accumulator 1; the contents of accumulator 2, accumulator 3, and accumulator 4 remain unchanged. This instruction gives a positive result when all the addresses are greater than zero (“0”). The only exception: the Square Root of -0 is -0. Table 10-8

Effects on Bits CC 1, CC 0, OV and OS of the Status Word

Example

Effects of Instruction SQR on Bits CC 1, CC 0, OV and OS

Result in Accumulator 1

CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Infinite (Overflow)

1

0

1

1

+ Valid

1

0

0

–

+ Not valid (Underflow)

0

0

1

1

+ Null

0

0

0

–

- qNaN

1

1

1

1

The following program extract is an example of how the instruction SQR is used.

ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ STL

Explanation

OPN DB17

Open data block DB17. (It is assumed that it contains the input value and will store the result).

L DBD0

Load the value in data double word DBD0 into accumulator 1. (The value in this double word must be in floating-point format.)

SQR

Calculate the square of the 32 bit IEEE floating-point number. Store the result in accumulator 1.

AN OV

Check that the status bit OV is 0.

JC OK

If operation SQR has no errors, jump tothe label OK

...

(In the event of an error an appropriate reaction takes place at this point.)

OK: T DBD4

Transfer the result of accumulator 1 to data double word DBD4.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-9

Floating-Point Math Instructions

Table 10-9

Effects of Instruction SQRT on Bits CC 1, CC 0, OV and OS

Result in Accumulator 1

Example

CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Infinite (Overflow)

1

0

1

1

+ Valid

1

0

0

–

+ Not valid (Underflow)

0

0

1

1

+ Zero

0

0

0

–

-Zero

0

0

0

–

- qNaN

1

1

1

1

The following program extract is an example of how the instruction SQRT is used.

STL

Explanation

L MD10

Load the value in memory double word MD10 into accumulator 1. (The value must be in floating-point format.) Form the square root of the 32 bit IEEE floating-point number in accumulator 1. Store the result in accumulator 1. Check that the status bit OV is 0. If operation SQR has no errors, jump to the label OK. (In the event of an error an appropriate reaction takes place at this point.) Transfer the result (accumulator 1) in the memory double word MD20.

SQRT AN OV JC OK ... OK: T MD20

10-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

10.5 Forming the Natural Logarithm of a Floating-Point Number

Description

The instruction LN (natural logarithm) calculates the natural logarithm of the floating-point number in accumulator 1 and stores the 32-bit result in accumulator 1. The input value must be greater than zero (0). The instruction LN overwrites the old contents of accumulator 1; the contents of accumulator 2, accumulator 3, and accumulator 4 remain unchanged.

Effects on Bits CC 1, CC 0, OV and OS of the Status Word

Table 10-10 shows the effects that the instruction LN has on the signal state of bits CC 1, CC 0, OV and OS of the status word. A hyphen (-) entered in a bit column of the table means that the bit in question is not affected by the result of the floating-point math instruction. Table 10-10

Effects of Instruction LN on Bits CC 1, CC 0, OV and OS CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Infinite (Overflow)

1

0

1

1

+ Valid

1

0

0

–

+ Not valid (Underflow)

0

0

1

1

+ Zero

0

0

0

–

-Zero

0

0

0

–

- Not valid (Underflow)

0

0

1

1

- Valid

0

1

0

–

- Infinite (Overflow)

0

1

1

1

- qNaN

1

1

1

1

Result in Accumulator 1

Example

The following program extract is an example of how the instruction LN is used.

ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ STL

Explanation

L MD10

Load the value from memory double word MD10 into accumulator 1. (The value must be in floating-point format.)

LN

Form the natural logarithm of the 32 bit IEEE floating-point number in accumulator 1. Store the result in accumulator 1.

AN OV

Check that the status bit OV is 0.

JC OK

If operation SQR has no errors, jump to the label OK.

...

(In the event of an error an appropriate at this point.)

OK: T MD20

Transfer the result from accumulator 1 to memory double word MD20.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

reaction takes place

10-11

Floating-Point Math Instructions

10.6 Forming the Exponential Value of a Floating-Point Number

Description

The instruction EXP (exponential value to base E) calculates the exponential value of the 32 bit IEEE floating-point number in accumulator 1 to base E (=2.71828) and stores the 32-bit result in accumulator 1. The input value must be greater than zero (0). The operation EXP overwrites the old contents of accumulator 1; the contents of accumulator 2, accumulator 3, and accumulator 4 remain unchanged.

Effects on Bits CC 1, CC 0, OV and OS of the Status Word

Table 10-11 shows the effects that the instruction EXP has on the signal state of bits CC 1, CC 0, OV and OS of the status word. A hyphen (-) entered in a bit column means that the bit in question is not affected by the result of the floating-point math instruction. Table 10-11

Effects of Instruction EXP on Bits CC 1, CC 0, OV and OS of the Status Word

Result in Accumulator 1

Example

CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Infinite (Overflow)

1

0

1

1

+ Valid

1

0

0

–

+ Not Valid (Underflow)

0

0

1

1

+ Zero

0

0

0

–

- qNaN

1

1

1

1

The following program extract is an example of how the instruction EXP is used.

ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ STL

Explanation

L MD10

Load the value from memory double word MD10 into accumulator 1. (The value must be in floating-point format.)

EXP

Form the exponential value on basis E of the 32 bit IEEE floating-point number in accumulator 1. Store the result in accumulator 1.

AN OV

Check that the status bit OV is 0.

JC OK

If operation EXP has no errors, jump to the label OK.

...

(In the event of an error an appropriate reaction takes place at this point.)

OK: T MD20

Transfer the result from accumulator 1 to memory double word MD20.

10-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

10.7 Forming Trigonometric Functions on Angles Acting as Floating-Point Numbers Description

Using the following instructions you can form trigonometric functions on angles acting as 32 bit IEEE floating-point numbers. The 32-bit result is stored in accumulator 1; the contents of accumulator 2, accumulator 3 and accumulator 4 remain unchanged. Instr.

Effects on Bits CC 1, CC 0, OV and OS of the Status Word

Function

SIN

Form the sine of the floating-point number of an angle expressed in radians. Store the angle as a floating-point number in ACCU1.

ASIN

Form the arc sine of a floating-point number in ACCU1. The result is an angle expressed in radians. The value will be in the following range: 
/ 2
cosecant (ACCU 1)
+  / 2,when  = 3.14...

COS

Form the cosine of the floating-point number of an angle expressed in radians. Store the angle as a floating-point number in ACCU1.

ACOS

Form the arc cosine of a floating-point number in ACCU1. The result is an angle expressed in radians. The value will be in the following range: 0
secant (ACCU 1)
+ , when  = 3.14...

TAN

Form the tangent of the floating-point number of an angle expressed in radians. Save the angle as a floating-point number in ACCU1.

ATAN

Form the arc tangent of a floating-point number in ACCU1. The result is an angle expressed in radians. The value will be in the following range: 
/ 2
cotangent (ACCU 1)
+  / 2, when  = 3.14...

Table 10-12 shows the effect that the instructions SIN, ASIN, COS, ACOS and ATAN have on the signal state of bits CC 1, CC 0, OV and OS in the status word. Table 10-13 shows how TAN affects these bits. A hyphen (–) means that the bit in question is not affected by the instruction. Table 10-12

Effects of Instructions SIN, ASIN, COS, ACOS and ATAN

Result in Accumulator 1

CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Valid

1

0

0

–

+ Infinite (Overflow)

0

0

1

1

+ Zero

0

0

0

–

-Zero

0

0

0

–

- Not valid (Underflow)

0

0

1

1

- Valid

0

1

0

–

- qNaN

1

1

1

1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-13

Floating-Point Math Instructions

Table 10-13

Effects of Instruction TAN on Bits CC 1, CC 0, OV and OS

Result in Accumulator 1

Example

CC 1

CC 0

OV

OS

+ qNaN

1

1

1

1

+ Infinite (Overflow)

1

0

1

1

+ Valid

1

0

0

–

+ Not valid (Underflow)

0

0

1

1

+ Zero

0

0

0

–

-Zero

0

0

0

–

–-Not valid (Underflow)

0

0

1

1

-Valid

0

1

0

–

- Infinite (Overflow)

0

1

1

1

- qNaN

1

1

1

1

The following program extract is an example of how the instruction SIN is used.

ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ STL

Explanation

L MD10

Load the value from memory double word MD10 into accumulator 1. (The value must be in floating-point format.)

SIN

Form the sine of the 32 bit IEEE floating-point number into accumulator 1. Store the result in accumulator 1.

T MD20

Transfer the result from accumulator 1 into memory double word MD20.

Example

The following program extract is an example of how the instruction ASIN is used.

ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ STL

Explanation

L MD10

Load the value from memory double word MD10 into accumulator 1. (The value must be in floating-point format.)

ASIN

Form the cosecant of the 32 bit IEEE floating-point number in accumulator 1. Store the result in accumulator 1.

AN OV

Check that the status bit OV is 0.

JC OK

If operation ASIN has no errors, jump to the label OK.

...

(In the event of an error an appropriate reaction takes place at this point.)

OK: T MD20

Transfer the result from accumulator 1 into memory double word MD20.

10-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Floating-Point Math Instructions

Evaluating the Bits in the Status Word

The extended math instructions affect the following bits in the status word:


CC 1 and CC 0
OV
OS

Valid Result

A hyphen (–) entered in a bit column of the table means that the bit in question is not affected by the result of the floating-point math instruction. Table 10-14

Inverse Functions for 32 Bit IEEE Floating-Point Numbers and Valid Ranges for the Value Input

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ Valid Range for a Floating-Point Result (32 Bits)

Bits of Status Word

CC 1 CC 0

OV

OS

+0, -0 (zero)

0

0

0

–

-3.402823E+38 t Result t -1.175494E–38 (negative number)

0

1

0

–

+1.175494E–38 t Result t 3.402823E+38 (positive number)

1

0

0

–

Table 10-15

Signal States of the Bits in the Status Word: Calculation Result with Floating-Point Numbers outside the Valid Range

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ Valid Range for a Floating-Point Result (32 Bits)

Bits of Status Word

CC 1 CC 0

OV

OS

-1.175494E–38 t Result t -1.401298E–45 (negative number) Underflow

0

0

1

1

+1.401298E–45 t Result t +1.175494E–38 (positive number) Underflow

0

0

1

1

Result t -3.402823E+38 (negative number) Overflow

0

1

1

1

Result u -3.402823E+38 (positive number) Overflow

1

0

1

1

Table 10-16

Signal States of the Bits in the Status Word: The Input Value Represents an Invalid Number or is outside the Valid Range

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁ ÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁ ÁÁÁ ÁÁÁ Valid Range for a Floating-Point Result (32 Bits)

Bits of Status Word

CC 1 CC 0

OV

OS

There is no valid 32-bit IEEE floating-point number in ACCU 1.

1

1

1

1

Instruction not permitted: the input value in ACCU 1 is outside the valid range.

1

1

1

1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-15

Floating-Point Math Instructions

10-16

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

11

Comparison Instructions Chapter Overview

Section

Description

Page

11.1

Overview

11-2

11.2

Comparing Two Integers

11-3

11.3

Comparing Two Floating-Point Numbers

11-5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

11-1

Comparison Instructions

11.1 Overview You can use the Compare instructions to compare the following pairs of numeric values:


Two integers (16 bits)
Two double integers (32 bits)
Two real numbers (IEEE floating-point, 32 bits) You load the numeric values into accumulators 1 and 2. A Compare instruction compares the value in accumulator 2 to the value in accumulator 1 according to the criteria listed in Table 11-1. The result of the comparison is a binary digit, that is, either a 1 or a 0. A 1 indicates that the result of the comparison is true; a 0 indicates that the result of the comparison is false (see Table 11-2). This result is stored in the result of logic operation bit (RLO bit, see Section 3.4). You can use this result in your program for further processing. When the CPU executes a Compare instruction, it also sets bits in the status word. Other statement list instructions can evaluate the bits of the status word. The CPU executes Compare instructions without regard to the result of logic operation. Table 11-1

Criteria for Comparisons

Type of Numeric Value in Accumulator 2

Integer (16 bits)

Comparison Criterion is equal to

==I ==D ==R

is not equal to

<>I <>D <>R

is greater than

>I >D >R

is less than


g ((32 bits)) Double integer Real number (floating-point, 32 bits)

11-2

Symbol(s) for Instruction

is greater than or equal to

>=I >=D >=R

is less than or equal to

<=I <=D <=R

Type of Numeric Value in Accumulator 1

Integer (16 bits) g ((32 bits)) Double integer Real number (floating-point, 32 bits)

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Comparison Instructions

11.2 Comparing Two Integers

Description

Table 11-2

The Compare Integer instructions compare two single integers (16 bits each) and the Compare Double Integer instructions compare two double integers (32 bits each) according to the criteria listed in Table 11-2. A sample program follows Table 11-3. Compare Integer and Compare Double Integer Instructions

Instruction Instruct on ==I ==D <>I <>D >I >D =I >=D <=I <=D

Explanation Explanat on The integer in the low word of accumulator 2 is equal to the integer in the low word of accumulator 1. The double integer in accumulator 2 is equal to the double integer in accumulator 1. The integer in the low word of accumulator 2 is not equal to the integer in the low word of accumulator 1. The double integer in accumulator 2 is not equal to the double integer in accumulator 1. The integer in the low word of accumulator 2 is greater than the integer in the low word of accumulator 1. The double integer in accumulator 2 is greater than the double integer in accumulator 1. The integer in the low word of accumulator 2 is less than the integer in the low word of accumulator 1. The double integer in accumulator 2 is less than the double integer in accumulator 1. The integer in the low word of accumulator 2 is greater than or equal to the integer in the low word of accumulator 1. The double integer in accumulator 2 is greater than or equal to the double integer in accumulator 1. The integer in the low word of accumulator 2 is less than or equal to the integer in the low word of accumulator 1. The double integer in accumulator 2 is less than or equal to the double integer in accumulator 1.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

11-3

Comparison Instructions

Setting Bits CC 1 and CC 0 of the Status Word

A Compare Integer or Compare Double Integer instruction sets certain combinations in the CC 1 and CC 0 bits to indicate what condition has been fulfilled (see Table 11-3). Table 11-3

Settings of Bits CC 1 and CC 0 after a Compare Instruction

Condition

Example

Signal states of CC 1 and CC 0:

Possible check with the instructions

CC 1

CC 0

A, O, X, AN, ON, XN

ACCU 2 > ACCU 1

1

0

>0

ACCU 2 < ACCU 1

0

1

<0

ACCU 2 = ACCU 1

0

0

==0

ACCU 2 <> ACCU 1

0 or 1

1 or 0

<>0

ACCU 2 >= ACCU 1

1 or 0

0 or 0

>=0

ACCU 2 <= ACCU 1

0 or 0

1 or 0

<=0

The following sample program shows how the Compare instructions for integers (16 bits) work.

STL

Explanation

L MW10

Load the contents of memory word MW10 into accumulator 1.

L

Load the contents of input word IW0 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2.

IW0

==I

Compare the value in the low word of accumulator 2 to the value in the low word of accumulator 1 to see if they are equal.

=

Output Q 4.0 will be energized if MW10 and IW0 are equal.

Q 4.0

Compare the value in the low word of accumulator 2 to see if it is greater than the value in the low word of accumulator 1.

>I

=

Q 4.1

Compare the value in the low word of accumulator 2 to see if it is less than the value in the low word of accumulator 1.


=

Output Q 4.1 will be energized if MW10 is greater than IW0.

Q 4.2 Output Q 4.2 will be energized if MW10 is less than IW0.

11-4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Comparison Instructions

11.3 Comparing Two Floating-Point Numbers Description

The Compare Floating-Point Number instructions compare two 32-bit IEEE floating-point numbers according to the criteria listed in Table 11-4. Because IEE 32-bit floating-point numbers belong to the data type called “REAL,” the mnemonic abbreviation for these instructions is R. Table 11-4

Compare Real Instructions (IEEE 32-bit Floating-Point Numbers)

Instruction Instruct on

Setting Bits of the Status Word

Explanation Explanat on

==R

The IEEE 32-bit floating-point number in accumulator 2 is equal to the IEEE 32-bit floating-point number in accumulator 1.

<>R

The IEEE 32-bit floating-point number in accumulator 2 is not equal to the IEEE 32-bit floating-point number in accumulator 1.

>R

The IEEE 32-bit floating-point number in accumulator 2 is greater than the IEEE 32-bit floating-point number in accumulator 1.


The IEEE 32-bit floating-point number in accumulator 2 is less than the IEEE 32-bit floating-point number in accumulator 1.

>=R

The IEEE 32-bit floating-point number in accumulator 2 is greater than or equal to the IEEE 32-bit floating-point number in accumulator 1.

<=R

The IEEE 32-bit floating-point number in accumulator 2 is less than or equal to the IEEE 32-bit floating-point number in accumulator 1.

A Compare Real number instruction sets certain combinations in the CC 1, CC 0, OV, and OS bits of the status word to indicate what condition has been fulfilled. Table 11-5

Settings of Bits of the Status Word after a Compare Real Instruction (IEEE 32-bit Floating-Point Numbers)

Condition

CC 1

CC 0

OV

OS

==

0

0

0

not applicable

<>

0 or 1

1 or 0

0

not applicable

>

1

0

0

not applicable

<

0

1

0

not applicable

>=

1 or 0

0 or 0

0

not applicable

<=

0 or 0

1 or 0

0

not applicable

UO

1

1

1

1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

11-5

Comparison Instructions

Evaluating the Bits of the Status Word

Other statement list instructions can evaluate the bits of the status word (see Section 5.3 and Table 11-6). Table 11-6

Instructions That Evaluate the CC 1, CC 0, OV, and OS Bits of the Status Word

Instruction A,O,X,AN,ON,XN

Example

Reference to Bits of the Status Word or Jump Section in Label this Manual >0, <0, <>0, >=0, <=0, ==0, UO, OV, OS

5.3

JUO

<jump label>

16.4

JZ

<jump label>

16.5

JN

<jump label>

16.5

JP

<jump label>

16.5

JM

<jump label>

16.5

JMZ

<jump label>

16.5

JPZ

<jump label>

16.5

The following sample program shows how the Compare Real number instructions work.

STL

Explanation

L MD24

Load the contents of memory double word MD24 into accumulator 1. Load the value 1 as a 32-bit floating-point number into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. Compare the value in accumulator 2 to see if it is greater than the value in accumulator 1. Output Q 4.1 will be energized if MD24 is greater than 1. Compare the value in accumulator 2 to see if it is less than the value in accumulator 1. Output Q 4.2 will be energized if MD24 is less than 1.

L

+1.00E+00

>R = Q 4.1
11-6

Q 4.2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12

Conversion Instructions Chapter Overview

Section

Description

Page

12.1

Converting Binary Coded Decimal Numbers and Integers

12-2

12.2

Converting 32-Bit Floating-Point Numbers to 32-Bit Integers

12-8

12.3

Reversing the Order of Bytes within Accumulator 1

12-13

12.4

Forming Complements and Negating Floating-Point Numbers

12-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-1

Conversion Instructions

12.1 Converting Binary Coded Decimal Numbers and Integers

Description

You can use the following instructions to convert binary coded decimal numbers and integers to other types of numbers: Mnemonic

12-2

Instruction

Function

BTI

BCD to Integer

This instruction converts a binary coded decimal value in the low word of accumulator 1 to a 16-bit integer.

BTD

BCD to Double Integer

This instruction converts a binary coded decimal value in accumulator 1 to a 32-bit integer.

ITB

Integer to BCD

This instruction converts a 16-bit integer in the low word of accumulator 1 to a binary coded decimal value.

ITD

Integer to Double Integer

This instruction converts a 16-bit integer in the low word of accumulator 1 to a 32-bit integer.

DTB

Double Integer to BCD

This instruction converts a 32-bit integer in accumulator 1 to a binary coded decimal value.

DTR

Double Integer to Real

This instruction converts a 32-bit integer in accumulator 1 to a 32-bit IEEE floating-point number (real number).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

BCD to Integer: BTI

The BCD to Integer (BTI) instruction converts a three-place binary coded decimal number (BCD number, see Figure 12-1) in the low word of accumulator 1 to a 16-bit integer. The BCD number can be in the range of -999 to +999. The result of the conversion is stored in the low word of accumulator 1. 15 14 13 12 S

S

S

11 10 9

8

7

6

5

4

3

2

1

0

S 102

101

100

Hundreds

Tens

Ones

Value of the BCD number These bits are not used during the transfer. Sign: 0000 stands for positive, 1111 stands for negative.

Figure 12-1

Structure of a Binary Coded Decimal Number to Be Converted to Integer

If a place of a BCD number is in the invalid range of 10 to 15, a BCDF error occurs during an attempted conversion. In this case, one of the following occurrences takes place:


The CPU goes into the STOP mode. “BCD Conversion Error” is entered in the diagnostic buffer with event ID number 2521.


If OB121 is programmed, it is called. The following sample program includes a BTI instruction. Figure 12-2 shows how this instruction works. STL

Explanation

L MW10 BTI

Load the BCD value in memory word MW10 into accumulator 1. Convert the BCD value to a 16-bit integer and store the result in accumulator 1. Transfer the result to memory word MW20.

T

MW20

“+”

“9”

“1”

15... L MW10

MW10

0 0 0 0

BTI T MW20

Figure 12-2

...8 1 0 0 1

“5”

7... 0 0 0 1

...0 0 1 0 1

“+915” BCD

0 0 1 1

“+915” integer

BCD to integer MW20

0 0 0 0

0 0 1 1

1 0 0 1

Using the BTI Instruction to Convert a BCD Number to a 16-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-3

Conversion Instructions

BCD to Double Integer: BTD

The BCD to Double Integer (BTD) instruction converts a seven-place binary coded decimal number (BCD number, see Figure 12-3) in accumulator 1 to a 32-bit integer. The BCD number can be in the range of -9,999,999 to +9,999,999. The result of the conversion is stored in accumulator 1. If a place of a BCD number is in the invalid range of 10 to 15, a BCDF error occurs during an attempted conversion. In this case, either one of the following occurrences takes place:


The CPU goes into the STOP mode. “BCD Conversion Error” is entered in the diagnostic buffer with event ID number 2521.


If OB121 is programmed, it is called. 31...

...16 15...

...0

SSSS 106

105

104

103

102

101

100

Value of the BCD number These bits are not used during the transfer. Sign: 0000 stands for positive, 1111 stands for negative.

Figure 12-3

Structure of a 32-Bit BCD Number to Be Converted to Double Integer

The following sample program includes a BTD instruction. Figure 12-4 shows how this instruction works. STL

Explanation

L

Load the BCD value in memory double word MD10 into accumulator 1. Convert the BCD value to a 32-bit integer and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

BTD T

MD20

“+” 31... L MD10

MD10

BTD T MD20

Figure 12-4

12-4

“0”

“1”

“5”

“7”

“8”

“2”

...16 15...

“1” ...0

0000 0000 0001 0101 0111 1000 0010 0001

“157821”

BCD to integer MD20

0000 0000 0000 0010 0110 1000 0111 1101

“+157821”

Using the BTD Instruction to Convert a BCD Number to a 32-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

Integer to BCD: ITB

The Integer to BCD (ITB) instruction converts a 16-bit integer in the low word of accumulator 1 to a three-place binary coded decimal number. The BCD number can be in the range of -999 to +999. The result of the conversion is stored in the low word of accumulator 1. If the integer is too large to be represented in BCD format, no conversion takes place and the overflow (OV) and stored overflow (OS) bits of the status word (see Section 3.4) are set to a signal state of 1. The following sample program includes an ITB instruction. Figure 12-5 shows how this instruction works.

STL

Explanation

L

Load the 16-bit integer value in memory word MW10 into accumulator 1. Convert the 16-bit integer to a BCD value and store the result in accumulator 1. Transfer the result to memory word MW20.

MW10

ITB T

MW20

15... L MW10

MW10

...8

1 1 1 1

1 1 1 0

ITB T MW20

...0

0 1 1 0

0 0 1 1

“-413” integer

0 0 1 1

“-413” BCD

Integer to BCD MW20

1 1 1 1

“–” Figure 12-5

7...

0 1 0 0

“4”

0 0 0 1

“1”

“3”

Using the ITB Instruction to Convert a 16-Bit Integer to a BCD Number

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-5

Conversion Instructions

Integer to Double Integer: ITD

The Integer to Double Integer (ITD) instruction converts a 16-bit integer in the low word of accumulator 1 to a 32-bit integer. The result of the conversion is stored in accumulator 1. The following sample program includes an ITD instruction. Figure 12-6 shows how this instruction works.

STL

Explanation

L

Load the 16-bit integer value in memory word MW10 into accumulator 1. Convert the 16-bit integer value to a 32-bit integer and store the result in accumulator 1. Transfer the result to memory double word MD20.

MW10

ITD T

MD20 15... L MW10

MW10

...0

1111 1111 1111 0110

ITD

Integer (16-bit) to integer (32-bit) ...16 15...

31... T MD20 Figure 12-6

MD20

“-10” integer

...0

1111 1111 1111 1111 1111 1111 1111

0110

“-10” integer

Using the ITD Instruction to Convert a 16-Bit Integer to a 32-Bit Integer

Double Integer to BCD: DTB

The Double Integer to BCD (DTB) instruction converts a 32-bit integer in accumulator 1 to a seven-place binary coded decimal value. The BCD number can be in the range of -9,999,999 to +9,999,999. The result of the conversion is stored in accumulator 1. If the double integer is too large to be represented in BCD format, no conversion takes place and the overflow (OV) and stored overflow (OS) bits of the status word (see Section 3.4) are set to a signal state of 1. The following sample program includes a DTB instruction. Figure 12-7 shows how this instruction works.

STL

Explanation

L

Load the 32-bit integer in memory double word MD10 into accumulator 1. Convert the 32-bit integer to a BCD value and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

DTB T

MD20 31... L MD10

MD10

...16 15...

1111 1111 1111 1111 1111 1101 0100 0011

DTB T MD20

12-6

“-701” integer

Integer to BCD MD20

1111 0000 0000 0000 0000 0111 0000 0001 “–”

Figure 12-7

...0

“0”

“0”

“0”

“0”

“7”

“0”

“-701” BCD

“1”

Using the DTB Instruction to Convert a 32-Bit Integer to a BCD Number

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

Double Integer to Real: DTR

The Double Integer to Real (DTR) instruction converts a 32-bit integer in accumulator 1 to a 32-bit IEEE floating-point number (real number). If necessary, the instruction rounds the result. The result of the conversion is stored in accumulator 1. The following sample program includes an DTR instruction. Figure 12-8 shows how this instruction works.

STL

Explanation

L

Load the 32-bit integer in memory double word MD10 into accumulator 1. Convert the 32-bit integer to a 32-bit IEEE floating-point value and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

DTR

T

MD20

L MD10

MD10

0000 0000 0000 0000 0000 0001 1111 0100

DTR

Integer (32-bit) to IEEE floating-point 31 30...

T MD20

“+500” integer

MD20

...0

22...

0 100 0011 1 111 1010 0000 0000 0000 0000 8-bit exponent

“+500” IEEE

23-bit mantissa

1 bit Sign of the mantissa Figure 12-8

Using the DTR Instruction to Convert a 32-Bit Integer to an IEEE 32-Bit Floating-Point Number

For a summary of the number conversions, see Figure 12-13 at the end of Section 12.2.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-7

Conversion Instructions

12.2 Converting 32-Bit Floating-Point Numbers to 32-Bit Integers

Description

You can use any of the following instructions to convert a 32-bit IEEE floating-point number in accumulator 1 to a 32-bit integer (double integer). The individual instructions differ in their method of rounding. Mnemonic

Instruction

Function

RND

Round

This instruction rounds the converted number to the nearest whole number. If the fractional part of the converted number is midway between an even and an odd result, the instruction chooses the even result.

RND+

Round to Upper Double Integer

This instruction rounds the converted number to the smallest whole number greater than or equal to the floating-point number that is converted.

RND-

Round to Lower Double Integer

This instruction rounds the converted number to the largest whole number less than or equal to the floating-point number that is converted.

TRUNC Truncate

This instruction converts the whole number part of the floating-point number.

The result of the conversion is stored in accumulator 1. If the number to be converted is not a floating-point number or is a floating-point number that cannot be represented as a 32-bit integer, no conversion takes place and an overflow is indicated.

12-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

Round: RND

The Round (RND) instruction converts a 32-bit IEEE floating-point number in accumulator 1 to a 32-bit integer (double integer) and rounds it to the nearest whole number. If the fractional part of the converted number is midway between an even and an odd result, the instruction chooses the even result. The following sample program includes an RND instrruction. Figure 18-9 shows how this instruction works.

STL

Explanation

L

Load the 32-bit IEEE floating-point value in memory double word MD10 into accumulator 1. Convert the 32-bit floating-point number to a 32-bit integer, round to the nearest whole number, and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

RND

T

MD20

31 30... L MD10

MD10

22...

0 100 0010 1 100 1001 0000 0000 0000 0000

T MD20

MD20

L MD10

MD10

0000 0000 0000 0000 0000 0000 0110 0100

31 30...

“+100” integer

...0

22...

1 100 0010 1 100 1001 0000 0000 0000 0000

“-100.5” IEEE

IEEE to integer (32-bit)

RND

Figure 12-9

“+100.5” IEEE

IEEE to integer (32-bit)

RND

T MD20

...0

MD20

1111 1111 1111 1111 1111 1111

1001 1100

“-100” integer

Using the RND Instruction to Convert an IEEE 32-Bit Floating-Point Number to a 32-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-9

Conversion Instructions

Round to Upper Double Integer: RND+

The Round to Upper Double Integer (RND+) instruction converts a 32-bit IEEE floating-point number in accumulator 1 to a 32-bit integer (double integer). The instruction rounds the converted number to the smallest whole number greater than or equal to the floating-point number that is converted. The following sample program includes an RND+ instruction. Figure 12-10 shows how this instruction works.

STL

Explanation

L

Load the 32-bit IEEE floating-point value in memory double word MD10 into accumulator 1. Convert the 32-bit floating-point number to a 32-bit integer. Round to the smallest whole number greater than or equal to the floating-point number that is converted and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

RND+

T

MD20

31 30... L MD10

MD10

22...

MD20

0000 0000 0000 0000 0000 0000 0110 0101

31 30... L MD10

MD10

Figure 12-10

12-10

22...

“+101” integer

...0

1 100 0010 1 100 1001 0000 0000 0000 0000

“-100.5” IEEE

IEEE to integer (32-bit)

RND+ T MD20

“+100.5” IEEE

IEEE to integer (32-bit)

RND+ T MD20

...0

0 100 0010 1 100 1001 0000 0000 0000 0000

MD20

1111 1111 1111 1111 1111 1111

1001 1100

“-100” integer

Using the RND+ Instruction to Convert an IEEE 32-Bit Floating-Point Number to a 32-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

Round to Lower Double Integer: RND-

The Round to Lower Double Integer (RND-) instruction converts a 32-bit IEEE floating-point number in accumulator 1 to a 32-bit integer (double integer). The instruction rounds the converted number to the largest whole number less than or equal to the floating-point number that is converted. The following sample program includes an RND- instruction. Figure 12-11 shows how this instruction works.

STL

Explanation

L

Load the 32-bit IEEE floating-point value in memory double word MD10 into accumulator 1. Convert the 32-bit floating-point number to a 32-bit integer. Round to the largest whole number less than or equal to the floating-point number that is converted and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

RND–

T

MD20

31 30... L MD10

MD10

22...

MD20

0000 0000 0000 0000 0000 0000 0110 0100

31 30... L MD10

MD10

Figure 12-11

22...

“+100” integer

...0

1 100 0010 1 100 1001 0000 0000 0000 0000

“-100.5” IEEE

IEEE to integer (32-bit)

RND– T MD20

“+100.5” IEEE

IEEE to integer (32-bit)

RND– T MD20

...0

0 100 0010 1 100 1001 0000 0000 0000 0000

MD20

1111 1111 1111 1111 1111 1111

1001 1011

“-101” integer

Using the RND– Instruction to Convert an IEEE 32-Bit Floating-Point Number to a 32-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-11

Conversion Instructions

Truncate: TRUNC

The Truncate (TRUNC) instruction converts a 32-bit IEEE floating-point number in accumulator 1 to a 32-bit integer (double integer). The instruction converts the whole number part of the floating-point number. The following sample program includes a TRUNC instruction. Figure 12-12 shows how this instruction works.

STL

Explanation

L

Load the 32-bit IEEE floating-point value in memory double word MD10 into accumulator 1. Convert the 32-bit floating-point number to a 32-bit integer. Round to the largest whole number less than or equal to the floating-point number that is converted and store the result in accumulator 1. Transfer the result to memory double word MD20.

MD10

TRUNC

T

MD20

31 30... L MD10

MD10

22...

MD20

0000 0000 0000 0000 0000 0000 0110 0100

31 30... L MD10

MD10

22...

Figure 12-12

“-100.5” IEEE

IEEE to integer (32-bit) MD20

1111 1111 1111 1111 1111 1111

1001 1100

“-100” integer

Using the TRUNC Instruction to Convert an IEEE 32-Bit Floating-Point Number to a 32-Bit Integer

Summary of Number Conversions

Figure 12-13 summarizes number conversions and rounding (see also Sections 12.1 and 12.2).

BCD 3-place 7-place

Figure 12-13

12-12

“+100” integer

...0

1 100 0010 1 100 1001 0000 0000 0000 0000

TRUNC T MD20

“+100.5” IEEE

IEEE to integer (32-bit)

TRUNC T MD20

...0

0 100 0010 1 100 1001 0000 0000 0000 0000

BTI ITB BTD DTB

Integer 16-bit 32-bit

Floating ITD DTR

32-bit IEEE

RND, RND+, RND–, TRUNC

Overview of Number Conversions and Rounding

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

12.3 Reversing the Order of Bytes within Accumulator 1

Description

You can use the following Change Bit Sequence in Accumulator 1 instructions to reverse the order of bytes in the low word of accumulator 1 or in the entire accumulator:


Change Byte Sequence in Accumulator 1, 16 bits (CAW)
Change Byte Sequence in Accumulator 1, 32 bits (CAD) CAW

CAW inverts the order of bytes in the low word of accumulator 1 (see Figure 12-14).

31... L MD10

...16 15...

...0

MD10

0101 1111 1010 0000 1111 1010 0101 0000

MD20

0101 1111 1010 0000 0101 0000 1111 1010

CAW T MD20

Figure 12-14

CAD

Using CAW to Reverse Byte Order in the Low Word of Accumulator 1

CAD inverts the byte order in all of accumulator 1 (see Figure 12-15).

31... L MD10

...16 15...

...0

MD10

0101 1111 1010 0000 1111 1010 0101 0000

MD20

0101 0000 1111 1010 1010 0000 0101 1111

CAD

T MD20 Figure 12-15

Using CAD to Reverse Byte Order in Accumulator 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-13

Conversion Instructions

12.4 Forming Complements and Negating Floating-Point Numbers

Description

Forming the ones complement of a number in the accumulator inverts the number bit by bit, that is, zeros are replaced by ones and ones are replaced by zeros. Forming the twos complement of an integer in the accumulator also inverts the number bit by bit, that is, zeros are replaced by ones and ones are replaced by zeros. Then a +1 is added to the contents of the accumulator. Forming the twos complement of an integer is the same as multiplying the number by a -1. Negating a real number inverts the sign bit. You can use one of the following instructions to form the complement of an integer or to invert the sign of a floating-point number: Mnemonic

12-14

Instruction

Function

INVI

Ones Complement Integer

This instruction forms the ones complement of the 16-bit value in the low word of accumulator 1. The result is stored in the low word of accumulator 1 (see Figure 12-16).

INVD

Ones Complement Double Integer

This instruction forms the ones complement of the 32-bit value in accumulator 1. The result is stored in accumulator 1.

NEGI

Twos Complement Integer

This instruction forms the twos complement of the 16-bit value in the low word of accumulator 1, that is, it multiplies it by -1. The result is stored in the low word of accumulator 1 (see Figure 12-17). In the status word (see Section 3.4), NEGI sets the CC 1, CC 0, OV and OS bits.

NEGD

Twos Complement Double Integer

This instruction forms the twos complement of the 32-bit value in accumulator 1, that is, it multiplies it by -1. The result is stored in accumulator 1. In the status word (see Section 3.4), NEGI sets the CC 1, CC 0, OV and OS bits.

NEGR

Negate FloatingPoint Number

This instruction inverts the sign bit of the 32-bit IEEE floating-point value in accumulator 1 (see Figure 12-18).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Conversion Instructions

Statement List Program L DBW30 INVI T DBW32

Load the value of data word DBW30 into the low word of accumulator 1. Form the ones complement of the value in the low word of accumulator 1. Transfer the contents of the low word of accumulator 1 to data word DBW32. Bit Patterns

L DBW30

0

1

0

1

1

1

0

0

0

1

1

1

0

0

0

1

1

Ones Complement Integer

INVI 1

T DBW32

Figure 12-16

1

0

1

0

0

0

1

0

1

1

0

0

0

1

Forming the Ones Complement of a 16-Bit Integer

Statement List Program L DBW40 NEGI T DBW42

Load the value of data word DBW40 into the low word of accumulator 1. Form the twos complement of the value in the low word of accumulator 1. Transfer the contents of the low word of accumulator 1 to data word DBW42. Bit Patterns

L DBW40

0

1

0

1

1

1

0

NEGI

0

0

1

1

1

0

0

0

“23,864” integer

0

0

“-23,864” integer

Twos Complement Integer

T DBW42

Figure 12-17

1

1

0

1

0

0

0

1

0

1

1

0

0

1

0

Forming the Twos Complement of a 16-Bit Integer

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-15

Conversion Instructions

Decimal value 10.0 Hexadecimal 4 value 31

Bits

1 28 27

2 24 23

0 20 19

0 16 15

0 12 11

0 8 7

0 4 3

0

0 1 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Sign of Mantissa: s (1 bit)

Exponent: e (8 bits)

Mantissa or fraction: f (23 bits)

e = 27 + 21 = 130 1.f  2e–bias = 1.25  23 = 10.0 [1.25  2(130–127) = 1.25  23 = 10.0]

f = 2–2 = 0.25

Statement List Program L DBD62 NEGR T DBD66

Load the value of data double word DBD62 into accumulator 1. Invert the sign of the value in accumulator 1. Transfer the contents of accumulator 1 to data double word DBD66.

L DBD62 0 1 0 0 0 0 0 1 0 0 1 0 NEGR

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

Negate Floating-Point Number

T DBD66 1 1 0 0 0 0 0 1 0 0 1 0

0 0 0 0 0 0 0 0 0 0 0 0

0 0 0 0 0 0 0 0

Sign of Mantissa (0 = positive, 1 = negative) Figure 12-18

12-16

Inverting the Sign of a Floating-Point Number

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

13

Word Logic Instructions Chapter Overview

Section

Description

Page

13.1

Overview

13-2

13.2

16-Bit Word Logic Instructions

13-3

13.3

32-Bit Word Logic Instructions

13-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

13-1

Word Logic Instructions

13.1 Overview

Description

Word logic instructions combine pairs of words (16 bits) or double words (32 bits) bit by bit according to Boolean logic. Each word or double word must be in one of the two accumulators.

Accumulator Administration

For words, the contents of the low word of accumulator 2 is combined with the contents of the low word of accumulator 1. The result of the combination is stored in the low word of accumulator 1, overwriting the old contents. For double words, the contents of accumulator 2 is combined with the contents of accumulator 1. The result of the combination is stored in accumulator 1, overwriting the old contents.

Influence on Bits of the Status Word

If the result of the logic combination is 0, the CC 1 bit of the status word is reset to 0. If the result of the logic combination is not 0, CC 1 is set to 1. In any case, the CC 0 and OV bits of the status word are reset to 0.

Available Instructions

The following instructions are available for performing word logic operations: Mnemonic

Constants as Addresses

Instruction

Function

AW

And Word

Combines two words bit by bit according to the And truth table

OW

Or Word

Combines two words bit by bit according to the Or truth table

XOW

Exclusive Or Word

Combines two words bit by bit according to the Exclusive Or truth table

AD

And Double Word

Combines two double words bit by bit according to the And truth table

OD

Or Double Word

Combines two double words bit by bit according to the Or truth table

XOD

Exclusive Or Double Word

Combines two double words bit by bit according to the Exclusive Or truth table

An AW, OW, or XOW instruction can use a 16-bit constant as its address. The instruction combines the contents of the low word of accumulator 1 with the 16-bit constant. An AD, OD, or XOD instruction can use a 32-bit constant as its address.

13-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Word Logic Instructions

13.2 16-Bit Word Logic Instructions

Description

The And Word, Or Word, and Exclusive Or Word instructions (AW, OW, XOW) combine pairs of words (16 bits) bit by bit according to Boolean logic. Mnemonic

RLO Before Logic Operation

Address

Result in RLO

AW

And Word

0 0 1 1

0 1 0 1

0 0 0 1

OW

Or Word

0 0 1 1

0 1 0 1

0 1 1 1

Exclusive Or Word

0 0 1 1

0 1 0 1

0 1 1 0

XOW

Relationship to Accumulators

Instruction

For the instructions that combine 16-bit words, the contents of the low word of accumulator 2 is combined with the contents of the low word of accumulator 1. The result of the logic combination is stored in the low word of accumulator 1, overwriting the old contents. The contents of the high word of accumulator 1 and both words of accumulator 2 remain unchanged (see Figure 13-1). Accumulator contents before word logic operation

Accumulator contents after word logic operation

Accumulator 2 31 16 15 III IV

Accumulator 2

Accumulator 1 31 16 15 II

Figure 13-1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

0

0 I

Combination AW, OW, XOW

IV

III

Accumulator 1 II

III c. I c = combined with

Combining the Contents of the Low Words of Accumulators 2 and 1

13-3

Word Logic Instructions

Example of an AW Instruction

The following sample program includes an AW instruction. Figure 13-2 shows how this instruction works.

STL

Explanation

L MW10

Load the contents of memory word MW10 into accumulator 1.

L

Load the contents of memory word mW20 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. The contents of the low word of accumulator 2 are combined bit by bit with the contents of the low word of accumulator 1 according to the AND truth table. The result is stored in the low word of accumulator 1. Transfer the contents of accumulator 1 to memory word MW24.

MW20

AW

T

MW24

15...

...8

7...

...0

MW10

0

1

1

0

0

1

0

1

1

1

1

0

1

0

1

0

MW20

1

0

1

0

1

0

1

0

0

1

0

1

0

1

1

1

0

1

0

0

0

0

1

0

AND bit by bit 0

MW24

Figure 13-2

Combining Accumulator and Constant

0

1

0

0

0

0

0

Combining Two Words Using the AW Instruction

An AW, OW, or XOW instruction can use a 16-bit constant as its address. The instruction combines the contents of the low word of accumulator 1 with the 16-bit constant that is indicated in the instruction statement. The result of the combination is stored in the low word of accumulator 1. Accumulator 2 and the high word of accumulator 1 remain unchanged (see Figure 13-3). Accumulator contents before word logic operation

Accumulator contents after word logic operation

Accumulator 2 31 16 15 IV III

Accumulator 2

Accumulator 1 31 16 15 II

0

0 I

Combination

IV

III

AW2#, OW2#, Accumulator 1 XOW2# II

I c. 2#

c = combined with Figure 13-3

13-4

Combining the Low Word of Accumulator 1 with a 16-Bit Constant

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Word Logic Instructions

Example of an AW Instruction with Constant

The following sample program includes an AW instruction that makes a logic combination with a 16-bit constant that is indicated in the instruction statement. Figure 13-4 shows how this instruction works.

STL

Explanation

L MW10

Load the contents of memory word MW10 into accumulator 1. The contents of the low word of accumulator 1 are combined bit by bit with 1010_1010_0101_0101 according to the AND truth table. The result is stored in the low word of accumulator 1. Transfer the contents of accumulator 1 to memory word MW24.

AW 2#1010_1010_0101_0101

T

MW24

15...

...8

7...

...0

MW10

0

1

1

0

0

1

0

1

1

1

1

0

1

0

1

0

Value of AW statement

1

0

1

0

1

0

1

0

0

1

0

1

0

1

0

1

1

0

0

0

0

0

0

AND Bit by Bit MW24

Figure 13-4

1

0

1

0

0

0

0

0

0

Using an AW Instruction with a 16-Bit Constant

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

13-5

Word Logic Instructions

13.3 32-Bit Word Logic Instructions

Description

The And Double Word, Or Double Word, and Exclusive Or Double Word instructions (AD, OD, XOD) combine pairs of words (32 bits) bit by bit according to Boolean logic. Mnemonic

Address

Result in RLO

And Double Word

0 0 1 1

0 1 0 1

0 0 0 1

OD

Or Double Word

0 0 1 1

0 1 0 1

0 1 1 1

Exclusive Or Double Word

0 0 1 1

0 1 0 1

0 1 1 0

For the instructions that combine double words, the contents of accumulator 2 is combined with the contents of accumulator 1. The result of the logic combination is stored in accumulator 1, overwriting the old contents. The contents of accumulator 2 remains unchanged (see Figure 13-5). Accumulator contents before word logic operation

Accumulator contents after word logic operation

Accumulator 2 31 16 15 IV III

Accumulator 2

Accumulator 1 31 16 15 II

Figure 13-5

13-6

RLO Before Logic Operation

AD

XOD

Relationship to Accumulators

Instruction

0 Combination

0 I

AD, OD, XOD

IV

III

Accumulator 1 IV c. II

III c. I c = combined with

Combining the Contents of Accumulators 2 and 1

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Word Logic Instructions

Example of an AD Instruction

The following sample program includes an AD instruction. Figure 13-6 shows how this instruction works.

STL

Explanation

L MD10

Load the contents of memory double word MD10 into accumulator 1. Load the contents of memory double word mD20 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. The contents of accumulator 2 are combined bit by bit with the contents of accumulator 1 according to the AND truth table. The result is stored in accumulator 1. Transfer the contents of accumulator 1 to memory double word MD24.

L

MD20

AD

T

MD24

31...

...16 15...

...0

MD10

0110 1001 1000 0001

1000 0000 1010 0111

MD20

1010 1010 1010 1010 0101 0101 0101 0101 AND bit by bit

MD24

Figure 13-6

0010 1000 1000 0000 0000 0000 0000 0101

Using an AD Instruction

Combining Accumulator and Constant

An AD, OD, or XOD instruction can use a 32-bit constant as its address. The instruction combines the contents of accumulator 1 with the 32-bit constant that is indicated in the instruction statement. The result of the combination is stored in accumulator 1. Accumulator 2 remains unchanged (see Figure 13-7). Accumulator contents before word logic operation

Accumulator contents after word logic operation

Accumulator 2 31 16 15

Accumulator 2

IV

0 Combination

III

Accumulator 1 31 16 15 II I

0

AD, OD, XOD DW#16#

IV

III

Accumulator 1 IIc.DW#16#Ic.DW#16# c=combined with

Figure 13-7

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Combining Accumulator 1 with a 32-Bit Constant

13-7

Word Logic Instructions

Example of an AD Instruction with Constant

The following sample program includes an AD instruction that makes a logic combination with a 32-bit constant that is indicated in the instruction statement. Figure 13-8 shows how this instruction works.

STL

Explanation

L MD10

Load the contents of memory double word MD10 into accumulator 1. The contents of accumulator 1 are combined bit by bit with DW#16#AAAA_5555 according to the AND truth table. The result is stored in accumulator 1. Transfer the contents of accumulator 1 to memory double word MD24.

AD

T

DW#16#AAAA_5555

MD24

31...

...16 15...

...0

MD10

0110 1001 1000 0001 1000 0000 1010 0111

Value of AD statement

1010 1010 1010 1010 0101 0101 0101 0101 AND bit by bit

MD24

Figure 13-8

13-8

0010 1000 1000 0000 0000 0000 0000 0101 Using an AD Instruction with a 32-Bit Constant

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14

Shift and Rotate Instructions Chapter Overview

Section

Description

Page

14.1

Shift Instructions

14-2

14.2

Rotate Instructions

14-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

14-1

Shift and Rotate Instructions

14.1 Shift Instructions

Shift Instructions

You can use the Shift instructions to move the contents of the low word of accumulator 1 or the contents of the whole accumulator bit by bit to the left or the right. Shifting by n bits to the left multiplies the contents of the accumulator by “2n”; shifting by n bits to the right divides the contents of the accumulator by “2n”. For example, if you shift the binary equivalent of the decimal value 3 to the left by 3 bits, you end up with the binary equivalent of the decimal value 24 in the accumulator. If you shift the binary equivalent of the decimal value 16 to the right by 2 bits, you end up with the binary equivalent of the decimal value 4 in the accumulator. The number that follows the shift instruction or a value in the low byte of the low word of accumulator 2 indicates the number of bits by which to shift. The bit places that are vacated by the shift instruction are either filled with zeros or with the signal state of the sign bit (a 0 stands for positive and a 1 stands for negative). The bit that is shifted last is loaded into the CC 1 bit of the status word (see Figure 2-7). The CC 0 and OV bits of the status word are reset to 0. You can use jump instructions to evaluate the CC 1 bit. The shift operations are unconditional, that is, their execution does not depend on any special conditions. They do not affect the result of logic operation.

Shift Functions: Unsigned Numbers

The following instruction shift the contents of the low word of accumulator 1 bit by bit to the left or right:


Shift Left Word (SLW, 16 bits)
Shift Right Word (SRW, 16 bits) The following instructions shift the entire contents of accumulator 1 bit by bit to the left or right:


Shift Left Double Word (SLD, 32 bits)
Shift Right Double Word (SRD, 32 bits) In all cases, the free bit positions are filled with a 0,

Shift Left Word: SLW

STL L

Explanation MW10

SLW T

The following sample program and Figure 14-1 provide an example of how the SLW instruction works. Table 14-1 provides a summary of all the Shift instructions.

6 MW20

14-2

Load the contents of memory word MW10 into the low word of accumulator 1. Shift the bits of the low word in accumulator 1 six places to the left. Transfer the contents of the low word of accumulator 1 to memory word MW20.

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Shift and Rotate Instructions

15... 0

0

0 0

1

1

...8

7...

1

0

1

0

1

0

1

0

1

0

1

0

0

0

0

0

0

1

...0

6 places 0

0

0

0

1

1

1

1

0

1

0

1

0

1

These five bits are lost. The bit that is shifted out last is stored in the CC 1 bit of the status word. Figure 14-1

The vacated places are filled with zeros.

Shifting Bits of the Low Word of Accumulator 1 Six Bits to the Left

Shift Right Double Word (32 Bits): SRD

The following sample program and Figure 14-2 provide an example of how the SRW instruction works. Table 14-1 provides a summary of all the Shift instructions.

STL

Explanation

L L

Load the value +3 into accumulator 1. Load the contents of memory double word MD10 into accumulator 1. The old contents of accumulator 1 (+3) is moved to accumulator 2. Shift the bits in accumulator 1 three places to the right. Transfer the contents of accumulator 1 to memory double word MD20.

+3 MD10

SRD T MD20

31...

...16 15...

...0

1111 1111 0101 0101 1010 1010 1111 1111 3 places 0001 1111 1110 1010 1011 0101 0101 1111 111 The vacated places are filled with zeros.

Figure 14-2

The bit that is shifted out last is stored in the CC 1 bit of the status word.

These two bits are lost.

Shifting Bits of Accumulator 1 Three Bits to the Right

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14-3

Shift and Rotate Instructions

Shift Functions: Signed Numbers

The Shift Sign Integer (SSI, 16 bits) instruction shifts the contents of the low word of accumulator 1 bit by bit to the right, including sign, as described in the overview of this chapter: The Shift Sign Double Integer (SSD, 32 bits) instruction shifts the entire contents of accumulator 1 bit by bit to the right, including sign. The shift bit is copied into the free bit positions.

Shift Sign Integer: SSI

The following sample program and Figure 14-3 provide an example of how the SSI instruction works. Table 14-1 provides a summary of all the Shift instructions.

STL

Explanation

L

Load the contents of memory word MW10 into the low word of accumulator 1. Shift the bits in the low word of accumulator 1, including sign, four places to the right. Transfer the contents of the low word of accumulator 1 to memory word MW20.

MW10

SSI T

4

MW20

15... 1

0

1 0

1

1

1

1

1

1

1

0

The vacated places are filled with the signal state of the sign bit.

Figure 14-3

14-4

7...

1

0

...0 0

0

0

1

0

1

0

1

1

1

0

0

0

0

4 places

Sign bit 1

...8

1

0

1

The bit that is shifted out last is stored in the CC 1 bit of the status word.

1

0

1

0

These three bits are lost.

Shifting Bits of the Low Word of Accumulator 1 Four Bits to the Right with Sign

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Shift and Rotate Instructions

Table 14-1

Overview of Shift Instructions

Instruction

1 2 3 4 5

Area Affected

Direction

Indication of Number of Places to Shift

Filler for Vacated Places

Shift Range1

SLW n

Low word of accumulator 1

Left

In the instruction statement

0

n=0 to 15

SLW

Low word of accumulator 1

Left

In the low byte of the low word of accumulator 2

0

0 to 2552

SLD n

Accumulator 1

Left

In the instruction statement

0

n=0 to 32

SLD

Accumulator 1

Left

In the low byte of the low word of accumulator 2

0

0 to 2553

SRW n

Low word of accumulator 1

Right

In the instruction statement

0

n=0 to 15

SRW

Low word of accumulator 1

Right

In the low byte of the low word of accumulator 2

0

0 to 2552

SRD n

Accumulator 1

Right

In the instruction statement

0

n=0 to 32

SRD

Accumulator 1

Right

In the low byte of the low word of accumulator 2

0

0 to 2553

SSI n

Low word of accumulator 1

Right

In the instruction statement

Sign bit

n=0 to 15

SSI

Low word of accumulator 1

Right

In the low byte of the low word of accumulator 2

Sign bit

0 to 2554

SSD n

Accumulator 1

Right

In the instruction statement

Sign bit

n=0 to 32

SSD

Accumulator 1

Right

In the low byte of the low word of accumulator 2

Sign bit

0 to 2555

If the number of bits by which to shift or rotate is 0, the instruction is executed like a NOP. For shift numbers greater than 16, the result of the shift function is W#16#0000 and CC 1 = 0. For shift numbers greater than 32, the result of the shift function is DW#16#0000_0000 and CC 1 = 0. For shift numbers greater than 15, the result of the shift function is W#16#0000 and CC 1 = 0 or W#16#FFFF and CC 1 = 1 depending on the sign (0 or 1). For shift numbers greater than 31, the result of the shift function is DW#16#0000_0000 (CC 1 = 0) or DW#16#FFFF_FFFF (CC 1 = 1) depending on the sign of the number of bits to be shifted.

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14-5

Shift and Rotate Instructions

14.2 Rotate Instructions

Description

You can use the Rotate instructions to rotate the entire contents of accumulator 1 bit by bit to the left or to the right. The Rotate instructions trigger functions that are similar to the shift functions described in Section 14.1. However, the vacated bit places are filled with the signal states of the bits that are shifted out of the accumulator. The number that follows the rotate instruction or a value in the low byte of the low word of accumulator 2 indicates the number of bits by which to rotate. Depending on the instruction, rotation takes place via the CC 1 bit of the status word (see Section 2.2). The CC 0 bit of the status word is reset to 0. The following Rotate instructions are available:


Rotate Left Double Word (RLD)
Rotate Right Double Word (RRD)
Rotate Accumulator 1 Left via CC 1 (RLDA)
Rotate Accumulator 1 Right via CC 1 (RRDA) If the number of bits that are rotated is 0, then the instruction is carried out as a Null Operation (NOP). Table 14-2

Overview of the Rotate Instructions Rotate via CC 1?

Direction

Indication of Number of Places to Shift

Shift Range

RLD n

No

Left

In the instruction statement

n=0 to 32

RLD

No

Left

In the low byte of the low word of accumulator 2

0 to 255

RRD

No

Right

In the instruction statement

0 to 32

RRD

No

Right

In the low byte of the low word of accumulator 2

0 to 255

RLDA

Yes

Left

1 (fixed)

RRDA

Yes

Right

1 (fixed)

Instruction

14-6

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Shift and Rotate Instructions

Rotate Left Double Word: RLD

Table 14-2 provides a summary of all the Rotate instructions. The following sample program and Figure 14-4 provide an example of how the RLD instruction works.

STL

Explanation

L

Load the contents of memory double word MD10 into accumulator 1. Rotate the bits in accumulator 1 three places to the left. Transfer the contents of accumulator 1 to memory double word MD20.

MD10

RLD 3 T MD20

31...

...16 15...

...0

1111 0000 1010 1010 0000 1111 0000 1111 3 places

111

1000 0101 0101 0000 0111 1000 0111 1111

The three bits that are shifted out are inserted in the vacated places.

Figure 14-4

The last bit shifted is also stored in CC 1.

Rotating Bits of Accumulator 1 Three Bits to the Left

Rotate Right Double Word: RRD

The following sample program and Figure 14-5 provide an example of how the RRD instruction works.

STL

Explanation

L L

Load the value +3 into accumulator 1. Load the contents of memory double word MD10 into accumulator 1. The old contents of accumulator 1 (+3) is moved to accumulator 2. Rotate the bits in accumulator 1 three places to the right. Transfer the contents of accumulator 1 to memory double word MD20.

+3 MD10

RRD T MD20

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14-7

Shift and Rotate Instructions

31...

...16 15...

...0

1010 1010 0000 1111 0000 1111 0101 0101 3 places

1011 0101 0100 0001 1110 0001 1110 1010 101 The three bits that are shifted out are inserted in the vacated places.

The last bit shifted is also stored in CC 1.

Figure 14-5

Rotating Bits of Accumulator 1 Three Bits to the Right

Rotate Accumulator 1 Left via CC 1: RLDA CC1 X

Figure 14-6 shows an example of how the RLDA instruction works.

31...

...16 15...

...0

1010 1010 0000 1111 0000 1111 0101 0101 1 place

1

1010 0100 0001 1110 0001 1110 1010 101X

The last bit shifted is also stored in CC 1.

Figure 14-6

Rotating Accumulator 1 One Bit to the Left via the CC 1 Bit of the Status Word

Rotate Accumulator 1 Right via CC 1: RRDA

14-8

The signal state of the CC 1 bit is loaded into the vacated bit place.

The RRDA instruction works in a manner similar to the RLDA instruction. The only difference is in the direction of the rotation.

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15

Data Block Instructions Chapter Overview

Section

Description

Page

15.1

Opening Data Blocks

15-2

15.2

Swapping Data Block Registers

15-2

15.3

Loading Data Block Lengths and Numbers

15-3

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15-1

Data Block Instructions

15.1 Opening Data Blocks

Description

You can use the Open a Data Block (OPN) instruction to open a data block as a shared data block or as an instance data block. The program itself can accomodate one open shared data block and one open instance data block at the same time.

Addressing Format

Tables 15-1 and 15-2 lists the addresses and their ranges for the OPN instruction. Table 15-1

Addresses of the Open a Data Block Instruction OPN

Data Block A Area

DB DI

Table 15-2

Maximum Address Range according to Addressing Type Direct

1 to 65,535

Memory Indirect [DBW] [DIW] [LW] [MW]

1 to 65,534

Addresses of the Open a Data Block Instruction OPN Transferred as Parameter Type of DB Opened

Address Parameter Format

DBpara

BLOCK_DB

DIpara

15.2 Swapping Data Block Registers

Description

15-2

You can use the Exchange Shared DB and Instance DB (CDB) instruction to exchange data block registers. A shared data block becomes an instance data block and vice versa.

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Data Block Instructions

15.3 Loading Data Block Lengths and Numbers

Description

You can use the following instructions to load the length (in bytes) or the number of a shared data block or an instance data block into accumulator 1:


Load Length of Shared DB in Accumulator 1 (L DBLG)
Load Number of Shared DB in Accumulator 1 (L DBNO)
Load Length of Instance DB in Accumulator 1 (L DILG)
Load Number of Instance DB in Accumulator 1 (L DINO) Examples

The following sample program illustrates how you can use the L DBLG instruction to jump to the label ERR if the length of a data block is 50 bytes or more. The statement at the label ERR calls FC10, which you have programmed as an appropriate reaction if the length of the data block in question is 50 bytes or more.

STL

Explanation OPN DB40

Open shared data block DB40.

L

DBLG

Load the length of the open data block into accumulator 1.

L

+50

Load the integer +50 into accumulator 1. The old contents of accumulator 1 (the length of the open data block) are moved to accumulator 2. Compare the contents of accumulator 2 (the length of the open data block) to the contents of accumulator 1 (+50).

>=I

JC

ERR

A =

I 0.0 M 1.0

If the length of the data block is greater than or equal to +50, jump to the label ERR. If the length of the data block is less than +50, continue to the next instruction statement. The program continues with an And instruction.

BEU End the current block, regardless of the result of logic operation. ERR: CALL FC10 FC10 contains an appropriate reaction in the event that the length of DB40 is 50 bytes or more.

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15-3

Data Block Instructions

The following sample program illustrates how you can use the L DBNO instruction to check the data block that is presently open in your program to see if it falls into a particular range of data blocks, for example, data block DB190 to data block DB250.

STL

Explanation L

DBNO

Load into accumulator 1 the number of the data block that is presently open.

L

+190

Load the integer +190 as lower limit into accumulator 1. The old contents of accumulator 1 (the number of the open data block) are moved to accumulator 2.


Compare the contents of accumulator 2 (the number of the open data block) to the contents of accumulator 1 (+190).

JC

ERR

If the number of the data block is less than +190, jump to the label ERR. If the number of the data block is not less than +190, continue to the next instruction statement.

L

DBNO

Load into accumulator 1 the number of the data block that is presently open.

L

+250

Load the integer +250 as upper limit into accumulator 1. The old contents of accumulator 1 (the number of the open data block) are moved to accumulator 2.

>I

JC

Compare the contents of accumulator 2 (the number of the open data block) to the contents of accumulator 1 (+250). ERR

SET = M 1.0

If the number of the data block is greater than +250, jump to the label ERR. If the number of the data block is not greater than +250, continue to the next instruction statement. Set the RLO to 1. Assign the RLO to memory bit M 1.0.

BEU End the current block, regardless of the result of logic operation. ERR: CALL FC10 FC10 contains an appropriate reaction in the event that the number of the data block that is currently open does not fall into the range of DB190 to DB250.

15-4

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16

Jump Instructions Chapter Overview

Section

Description

Page

16.1

Overview

16-2

16.2

Unconditional Jump Instructions

16-3

16.3

Conditional Jump Instructions Based on Result of Logic Operation

16-4

16.4

Conditional Jump Instructions Based on BR, OV, or OS Bits of the Status Word

16-5

16.5

Conditional Jump Instructions Based on Result in the CC 1 and CC 0 Bits of the Status Word

16-6

16.6

Loop Control

16-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

16-1

Logic Control Instructions

16.1 Overview

Instructions

You can use the following Jump and Loop instructions to control the flow of logic, enabling your program to interrupt its linear flow to resume scanning at a different point. The address of a Jump or Loop instruction is a label. Instruction

Explanation Unconditional jump instructions

JU

Jump Unconditional

JL

Jump to List Conditional jump instructions, condition based on RLO

JC

Jump if RLO = 1

JCN

Jump if RLO = 0

JCB

Jump if RLO = 1 WITH BR

JNB

Jump if RLO = 0 WITH BR Conditional jump instructions, condition based on result in CC 1 and CC 0

JBI

Jump If BR = 1

JNBI

Jump If BR = 0

JO

Jump If OV = 1

JOS

Jump If OS = 1 Conditional jump instructions, condition based on result in CC 1 and CC 0

JZ

Jump If Zero

JN

Jump If Not Zero

JP

Jump If Plus

JM

Jump If Minus

JMZ

Jump If Minus or Zero

JPZ

Jump If Plus or Zero

JUO

Jump If Unordered Loop control

LOOP

Jump if the contents of Accumulator 1 > 0

Although the Master Control Relay instructions also control the flow of logic in a program, they are not included in this chapter. For information on MCR instructions, see Sections 17.4 and 17.5.

Jump Label

16-2

A jump label can be the address of a jump instruction or serve as a marker for the destination of a jump instruction. It consists of a maximum of four characters. The first character must be a letter of the alphabet; the other characters can be letters or numbers (for example, SEG3:). When used as a destination marker, the jump label must be closed with a colon. In this case, a statement must follow the jump label (for example, SEG3: NOP 0).

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Logic Control Instructions

16.2 Unconditional Jump Instructions Description

You can use the following jump instructions to interrupt the normal flow of your program unconditionally:


Jump Unconditional (JU)
Jump to List (JL) Jump Unconditional: JU

A Jump Unconditional (JU) instruction in your program interrupts the normal flow of logic control and causes the program to jump to a label (the address of the JU instruction). The label marks the point at which the program should continue. The jump is made regardless of any condition.

Jump to List: JL

The Jump to List (JL) instruction is a jump distributor. It is followed by a series of unconditional jumps to labels (see Figure 16-1). Access to the list is in accumulator 1.

Start

=0

Seg. 0

Selection according to Segment Number (jump distributor) =1 =2 =3

Seg. 1

L

MB100

JL

LIST

JU

SEG0

JU

SEG1

JU

COMM

JU

SEG3

JU

COMM

>3

Seg. 3

LIST:

Load destination: 0 = Jump to SEG0 1 = Jump to SEG1 2 = Jump to GEM 3 = Jump to SEG3 >3 = Jump to LIST

Jump distributor with length of four

SEG0: Program Segment 0 JU Common Program

COMM

SEG1: Program Segment 1 JU

End

COMM

SEG3: Program Segment 3 COMM: Common Program

Figure 16-1

Controlling the Flow of Logic Control Using the Jump to List Instruction JL

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16-3

Logic Control Instructions

16.3 Conditional Jump Instructions Founded on Result of Logic Operation Description

The following jump instructions interrupt the flow of logic in your program based on the result of logic operation (RLO) produced by the previous instruction statement:


Jump If RLO = 1 (JC)
Jump If RLO = 0 (JCN)
Jump If RLO = 1 with BR (JCB): The RLO is saved in the BR bit of the status word.


Jump If RLO = 0 with BR (JNB): The RLO is saved in the BR bit of the status word. Irrespectively of the jump, the following status word bits are described: OR :=0 STA :=1 RLO :=1 FC :=0

Start

I 1.0 = 1 and I 1.1 = 1?

No RLO=1

Program Section B Yes RLO=0 Erase MB10

IF RLO=0

A

I1.0

A

I1.1

JCN COMM L

0

T

MB10

COMM:

Section B

Common Program

Common Program

End

Figure 16-2

16-4

Controlling the Flow of Logic Control Using the Jump If RLO = 0 Instruction JCN

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Logic Control Instructions

16.4 Conditional Jump Instructions Founded on BR, OV, or OS Bits of the Status Word Description

The following jump instructions interrupt the flow of logic in your program based on the signal state of a bit in the status word (see Section 2.2).
Jump If BR = 1 with BR (JBI) or Jump If BR = 0 (JNBI)
Jump If OV = 1 ( JO) or Jump If OS = 1 (JOS) The JBI and JNBI instructions reset the OR and FC bits of the status word to 0 and set the STA bit to 1. The JOS instruction resets the OS bit to 0. Start

Reset OS Bit

JOS ODEL ODEL:

Calculate <MW10>=<MW12>+<MW14>–<MW16>

L

MW12

L

MW14

+

I

L

MW16

–

I

T

MW10

Reset OS Bit

Calculate

Overflow stored?

Yes

JOS SECC*

Section C No

JPZ SECB

Erase <MB10> Result <MW10>
0

Yes

SECB:

No

L

+10

T

MW20

JU

COMM

L

+17

T

MW30

JU

COMM

L

0

T

MW10

Section A

Section B

Section A

Section B

<MW20> = 10

<MW30> = 17

SECC:

Section C

COMM: Common Program Common Program

End Figure 16-3

* In this case, do not use the JO instruction. The JO instruction would check only the previous – I instruction if an overflow occurred.

Controlling the Flow of Logic Control Using the Jump If OS = 1 Instruction JOS, JP

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

16-5

Logic Control Instructions

16.5 Conditional Jump Instructions Based on Result in the CC 1 and CC 0 Bits of the Status Word

Description

The following jump instructions interrupt the flow of logic in your program based on the result of a calculation:


Jump If Zero (JZ)
Jump If Not Zero (JN)
Jump If Plus (JP, that is, greater than zero)
Jump If Minus (JM, that is, less than zero)
Jump If Minus or Zero (JMZ, that is, less than or equal to zero)
Jump If Plus or Zero (JPZ, that is, greater than or equal to zero, see Figure 16-4)


Jump If Unordered (JUO, that is, if one of the numbers in a floating-point math operation is not a valid floating-point number)

CC 1 and CC 0 in the Status Word

The status word bits CC 1 and CC 0 are described, irrespectively of the result of the previous operation. The signal states of the CC 1 and CC 0 bits of the status word indicate the conditions shown in Table 16-1. Table 16-1

Relationship of CC 1 and CC 0 to Conditional Jump Instructions

Signal State

16-6

Result of Calculat Calculation on

Jump Instruct Instruction on Tr Triggered ggered

0

=0

JZ

1 or 0

0 or 1

<>0

JN

1

0

>0

JP

0

1

<0

JM

0 or 1

0 or 0

>=0

JPZ

0 or 0

0 or 1

<=0

JMZ

1

1

UO (unordered)

JUO

CC 1

CC 0

0

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Logic Control Instructions

Start

Reset OS–Bit

JOS ODEL ODEL:

Calculate <MW10>=<MW12>+<MW14>–<MW16>

L

MW12

L

MW14

+

I

L

MW16

–

I

T

MW10

Reset OS–Bit

Calculate

Overflow stored?

Yes

Section C

JOS SECC*

Erase <MB10>

JPZ SECB

No

Result <MW10> >=0?

Yes

SECB:

No

L

+10

T

MW20

JU

COMM

L

+17

T

MW30

JU

COMM

L

0

T

MW10

Section A

Section B Section A

Section B

<MW20> = 10

<MW30> = 17

SECC:

Section C

COMM: Common Program Common Program

End

Figure 16-4

* In this case, do not use the JO instruction. The JO instruction would check only the previous – I instruction if an overflow happened.

Controlling the Flow of Logic Control Using the Jump If Plus or Zero Instruction JPZ

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

16-7

Logic Control Instructions

16.6 Loop Control

Description

You can use the Loop (LOOP) instruction to call a program segment multiple times (see Figure 16-5). The Loop instruction decrements the low word of accumulator 1 by 1. Then the value in the low word of accumulator 1 is tested. If it is not 0, a jump is executed to the label indicated in the address of the Loop instruction; otherwise the next instruction is executed.

Providing a Label as Address

You provide the Loop instruction with a label so it knows the point to which it should return in the program. For example, the Loop instruction in the program shown in Figure 22-5 has the label NEXT as its address. This label tells the instruction to return to the statement T MB10 in th program. At this point, the program processes Section A. The Loop instruction returns to the label as many times as you tell it to. You provide this information in the low word of accumulator 1. One way to do this is to set up a loop counter and load it into the accumulator.

Start

Initialize Loop Counter

Program Section A

NEXT:

L

+5

T

MB10

Initialize Loop Counter

Section A Decrement Loop Counter by 1 L

MB10

LOOP NEXT Yes

Loop Counter <> 0? No End

Figure 16-5

16-8

Using the Loop Instruction to Call a Program Segment Multiple Times

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Logic Control Instructions

Setting Up a Loop Counter

You provide the Loop instruction with a value that indicates how many times you want LOOP to call a particular program segment. The Loop instruction interprets the loop counter as a WORD data type. Table 16-2 provides information about the two possible formats for a loop counter. Table 16-2

Using the Loop Instruction Efficiently

Possible Format for a Loop Counter

Value Type

Value Range

Data Type

Memory Area

Integer

1 to 65,535 (positive value only)

WORD

I, Q, M, D, L

Word

W#16#0001 to W#16#FFFF

WORD

I, Q, M, D, L

In order to avoid running a loop more times than is necessary, you need to be aware of the following characteristics of the Loop instruction:


If you initialize the loop counter with a 0, the loop is executed 65,535 times.


You should avoid initializing the loop counter with a negative number.

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16-9

Logic Control Instructions

16-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Program Control Instructions Chapter Overview

Section

Description

17 Page

17.1

Parameter Assignment when Calling FCs and FBs

17-2

17.2

Calling Functions and Function Blocks with CALL

17-3

17.3

Calling Functions and Function Blocks with CC and UC

17.4

Working with Master Control Relay Functions

17-10

17.5

Master Control Relay Instructions

17-11

17.6

Ending Blocks

17-16

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17-7

17-1

Program Control Instructions

17.1 Parameter Assignment when Calling FCs and FBs

Terms

When calling blocks that require parameters the terms formal parameters and actual parameters play an important role. A formal parameter is a parameter whose name and data type are assigned and declared (for example, as INPUT, OUTPUT parameters) when the block is created. When a block is called in the Incremental Editor (for example CALL SFC31), STEP 7 automatically displays a list of all the formal parameters. The next step is to assign actual parameters to the formal parameters. An actual parameter is a parameter which functions and function blocks use during the actual run time of the user program. The following diagram shows the call of SFC31 “QRY_TINT” (Query Time-of-Day Interrupt) in STL. STL Representation

CALL SFC 31 OB_NO := 10 RET_VAL:= MW 22 STATUS := MW 100

Actual parameters Formal parameters

17-2

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Program Control Instructions

17.2 Calling Functions and Function Blocks with CALL

Description

You can use the Call (CALL) instruction to call functions (FCs) and function blocks (FBs) that you have created for your program or that you have received as standard functions and standard function blocks from Siemens. The Call instruction calls the FC or FB that you indicate as an address regardless of the result of logic operation or any other condition. When you use the Call instruction to call a function block, you must supply the function block with an instance data block (instance DB) or declare it as a local instance. The instance data block stores all the static variables and actual parameters of the function block. If you need information on how to program a function or a function block, or how to work with their parameters, see the STEP 7 Online Help.

Formal Parameters and Actual Parameters

When calling a function (FC) or a function block (FB), you must assign corresponding actual parameters to the declared formal parameters.

Specifying the Actual Parameters

The actual parameters used when a function (FC) or function block (FB) is called are generally specified symbolically. Absolute addressing of actual parameters is possible only for an address whose maximum size is a double word (for example, I 1.0, MB2, QW4, ID0).

The actual parameter that is specified when a function block is called must have the same data type as the formal parameter.

When you call a function, all formal parameters must be supplied with actual parameters. You only need to declare the actual parameters when these are different to the parameters of the previous call (actual parameters remain stored in the instance data block after the processing of the function block has been completed). When you call a function block, the Call instruction copies one of the following items into the instance data block of the function block, depending on the data type of the actual parameter and on the declaration of the formal parameter (IN, OUT, IN_OUT):


The value of the actual parameter
A pointer to the address of the actual parameter
A pointer to the L stack of the calling block where the value of the actual parameter has been buffered

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17-3

Program Control Instructions

Calling an FB with Instance DB and Block Parameters

The call can take place once the following details are entered:


The name of the function block
The name of the instance data block and
The parameters (if the actual parameter is a data block, the complete absolute address must always be specified, for example DB1.DBW2). The call uses either with an absolute or a symbolic address. Absolute Call: CALL FBx,DBy (pass parameters); x = block number y = data block number Symbolic Call: CALL fbname,datablockname (pass parameters); fbname = symbolic block name datablockname = symbolic data block name

Examples

The following example shows the call of function block FB40 with instance data block DB41. In this example, the formal parameters have the following data types: IN1: BOOL IN2: WORD OUT1: DWORD

STL

Explanation

CALL IN1:=

FB40,DB41 I1.0

IN2:=

MW2

OUT1:=

MD20

L

MD20

Call of FB40 with instance data block DB41. IN1 (formal parameter) is supplied with I 1.0 (actual parameter). IN2 (formal parameter) is supplied with MW2 (actual parameter). OUT1 (formal parameter) is supplied with MD20 (actual parameter). With this instruction, the program accesses the formal parameter OUT1.

The following example shows the call of function block FB50 with instance data block DB51. In this example, the formal parameters have the following data types: IN10: BOOL OUT11: STRUCT V1: BOOL V2: INT END_STRUCT

17-4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Program Control Instructions

STL CALL IN10:=

Explanation FB50,DB51 I1.0

OUT11:= ACTPA11

Call of FB50 with instance data block DB51. IN10 (formal parameter) is supplied with I 1.0 (actual parameter). Here it is not possible to specify an absolute actual parameter (for example, MW10) because the formal parameter OUT11 was defined as a structure. Instead, the symbolic actual parameter ACTPA11 is specified. Please note that ACTPA11 has the same structure as the formal parameter OUT11.

Access to the values of the structure OUT11 in FB50 would be made as follows:

STL A L

Explanation OUT11.V1 OUT11.V2

Calling Multiple Instances

Perform an AND logic operation on the bit OUT11.V1. Load word OUT11.V2 into accumulator 1.

The call can take place once the following details are entered:


The instance name (= name of a static variable of the type FB z) and
The Parameters The call always has a symbolic designation. CALL Instance Name (pass parameters);

STL

Explanation

FUNCTION_BLOCK FB 11 Source file VAR loc_inst : FB 10; Declaration of a multiple instance with data type FB10 END_VAR BEGIN NETWORK CALL #loc_inst ( Call of the multiple instance with syntax in_bool := M Parameter pass 0.0); (in_bool in this case is a variable declared in FB10)

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17-5

Program Control Instructions

Calling an FC with Block Parameters

The call can take place once the following details are entered:


The name of the fucntion block and
The parameters The call is addressed either with an absolute or a symbolic name. Absolute Call: CALL FCx (pass parameters); x = block number Symbolic Call: CALL fcname (pass parameters); fcname = symbolic block name

Example

The following example shows the call of function FC80 with block parameters. In this example, the formal parameters have the following data types: INC1: BOOL INC2: INT OUT: WORD

STL

Explanation

CALL FC80 INC1:= M 1.0

Call FC80. INC1 (formal parameter) is supplied with M 1.0 (actual parameter). INC2 (formal parameter) is supplied with IW2 (actual parameter). OUT (formal parameter) is supplied with QW4 (actual parameter).

INC2:= IW2 OUT:=

QW4

Calling an FC That Delivers a Return Value

17-6

You can create a function (FC) that delivers a return value (RET_VAL). For example, if you want to create a floating-point math function, you can use this return value as an output for the result of your function. When you call this function in your program, you provide the output “RET_VAL” with a double word location to accommodate the 32-bit result of your floating-point math function.

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Program Control Instructions

17.3 Calling Functions and Function Blocks with CC and UC

Description

You can use the following instructions to call functions (FCs) and function blocks (FBs) that you have created for your program in the same way as using the Call instruction. Using these instructions, you cannot transfer parameters.


Conditional Call (CC): Calls the function or function block that you indicate as an address if the result of logic operation is 1.


Unconditional Call (UC): Calls the function or function block that you indicate as an address regardless of the result of logic operation or any other condition. It is not possible for function blocks which are called with either a CC or a UC instruction to have associated data blocks.

Addressing Format

A CC or UC instruction can call a function (FC) or a function block (FB) using direct or memory indirect addressing or via an FC or FB transferred as a parameter (see Tables 17-1 and 17-2). The address is FC plus the number of the FC. Table 17-1 FC or FB Part of Address FC FB

Table 17-2

Addresses of CC and UC Instructions: Direct and Indirect Addressing Maximum Range of Address Number according to Addressing Type Direct

0 to 65,535

Name of the formal parameter or a symbolic name

Example

[DBW] [DIW] [LW] [MW]

0 to 65,534

Addresses of CC and UC Instructions: FC Transferred as Parameter Address

1

Memory Indirect

Parameter Data Types BLOCK_FC 1 BLOCK_FB 1

Parameters of type BLOCK_FC or BLOCK_FB cannot be used with the CC command in FCs and FBs.

To call an FC that you had created and given the number 12, you would use one of the following instructions, depending on whether you want the call to be conditional or not: CC FC12 (Call FC12 if the RLO is 1.) UC FC12 (Call FC12 no matter what the RLO is.)

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

17-7

Program Control Instructions

Assigning Actual Parameters

Table 17-3

Depending on the data type there are various ways to assign actual parameters to the formal parameters when you call a function or a function block. The following table is compiled according to the length of the data type.

Assigning Actual Parameters

Data Type of Formall Parameter F P t

BOOL (Bit)

Example of Assigning an Actual Parameter Direct Input (Value) TRUE

Input of a Shared Data Element M 100.0

Symbolic Input1 #OK_BIT

I 0.0 Q 0.0 DBX 3.0 BYTE (Byte)

B#16#1F

MB 100

#TYP_BYTE

IB 0 QB 0 CHAR

’K’

DBB 1

#TYP_CHAR

WORD (Word)

W#16#1F12

MW 100

#TYP_WORD

2#0001_1111_0001_0010

IW 0

C#32

QW 0

B#(5,25)

DBW 2

INT (Integer)

27

#TYP_INT

–25 S5TIME (S5 Time)

S5T#10MS

#TYP_S5_TIME

DATE (IEC Date)

D#1995–12–24

#TYP_DATE

DWORD (Double Word)

DW#16#FFFF_0F02

MD 100

2#0001_1111_0001_0010_0001 _1111_0001_0010

ID 0

B#(5,4,59,8)

#TYP_DWORD

QD 0 DBD 4

DINT (Double Integer)

L#170

REAL (FloatingPoint Number)

1.23

#TYP_REAL

TIME (IEC Time)

T#20MS

#TYP_TIME

TIME_OF_DAY (IEC Time-of-Day)

TOD#23:59:12.3

#TYP_TOD

17-8

#TYP_DINT

L#-350

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Program Control Instructions

Table 17-3

Assigning Actual Parameters, continued

Data Type of Formal Parameter

Example of Assigning an Actual Parameter Direct Input (Value)

DATE_AND_TIME (IEC Date and Time)

Not possible

ANY (Data type of any type and size)

P#M0.0 BYTE20

Input of a Shared Data Element

Symbolic Input1 #TYP_8_BYTE

(Variable must be declared, for example, temporary variable)

20 bytes 2 ... ... from bit memory 0.0 3

E 0.0

#TYP_ANYTYP

MB 5

(Declaration of arrays and structures)

AW 2

Prefix for ANY pointer

(Use of any STEP 7 shared addresses possible)

P#DB58.DBX16.0 BYTE14 14 bytes 2 ... ... in DB58 from data bit 16.0 3 Prefix for ANY pointer 1

2 3

Prerequisite: In the case of shared data, the name (= symbol) must be declared in the symbol table before it can be used as an actual parameter. In the case of local data, the name (= symbol) must be declared in the declaration table of the block before it can be used as an actual parameter. Local data symbols must be preceded by a hash #. Length specification can include elementary data types, for example BOOL, BYTE, WORD or DWORD or complex types, for example DATE_AND_TIME. Always enter a bit address; in length specifications enter 0 as the bit address (exception: BOOL).

Conditional Call in STL

In order to call an SFC conditionally, you can follow a sequence similar to the following:

STL

Explanation

A #OK_BIT_MEMORY JCNB m001 CALL SFC 28 OB_NO := 10 SDT := #OUT_TIME_DATE PERIOD := W#16#1201 RET_VAL := MW 200 m001: A BR = M 202.3

Condition for the call If the condition is not fulfilled (RLO=0), the call of the SFC is jumped and the RLO in the status bit is saved.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Check status bit BR

17-9

Program Control Instructions

17.4 Working with Master Control Relay Functions

Description

The Master Control Relay (MCR) is an American relay ladder logic master switch for energizing and de-energizing power flow (current path). A de-energized current path corresponds to an instruction sequence that writes a zero value instead of the calculated value, or, to an instruction sequence that leaves the existing memory value unchanged. Operations triggered by the following bit logic and transfer instructions are dependent on the MCR:


=
S
R
T (used with byte, word, or double word) The T instruction used with byte, word, or double word, and the = instruction write a 0 to the memory if the MCR is 0. The S and R instructions leave the existing value unchanged. Table 17-4

Operations Dependent on MCR and How They React to Its Signal State

Signal State of MCR 0

1

17-10

=

S or R

T

Writes 0

Does not write

Writes 0

(Imitates a relay that falls to its quiet state when voltage is removed)

(Imitates a latching relay that remains in its current state when voltage is removed)

(Imitates a component that, on loss of voltage, produces a value of 0)

Normal execution

Normal execution

Normal execution

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Program Control Instructions

17.5 Master Control Relay Instructions

Overview

You can use the following statements to implement a master control relay:

Description: MCRA, MCRD


MCRA

Activate MCR Area


MCRD

Deactivate MCR Area


MCR(

Save RLO in MCR Stack, Begin MCR Area


)MCR

End MCR Area

The following instructions activate or deactivate an MCR area, that is, they specify which instructions in your program depend on the MCR (see also Figure 17-1):


Activate MCR Area: MCRA
Deactivate MCR Area: MCRD The instructions that are programmed between the MCRA and the MCRD statements depend on the signal state of the MCR bit. The instructions that are programmed outside an MCRA-MCRD sequence do not depend on the signal state of the MCR bit. If an MCRD instruction is missing, the instructions programmed between an MCRA instruction and a BEU instruction depend on the MCR bit (see Figure 17-1). You must program the MCR dependency of functions (FCs) and function blocks (FBs) in the blocks themselves, that is, if such a function or function block is called from an MCRA-MCRD sequence, all the commands within that sequence are not automatically dependent on the MCR bit. To make the instructions in a called block dependent on the MCR bit, you must use the MCRA instruction in the block that is called.

!

Danger Never use the MCR instruction as an emergency off or personnel safety device.

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17-11

Program Control Instructions

ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ OB1

MCRA

ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ FBx

ÀÀÀÀÀÀÀ ÀÀÀÀÀÀÀ ÀÀÀÀÀÀÀ ÀÀÀÀÀÀÀ ÀÀÀÀÀÀÀ FCy

MCRA

MCRA

ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ MCRD

CALL FBx

MCRA

CALL FCy

ÀÀÀÀÀÀ ÀÀÀÀÀÀ ÀÀÀÀÀÀ MCRD

BEU

BEU

Instructions do not depend on the MCR bit Instructions depend on the MCR bit

Figure 17-1

17-12

Activating and Deactivating a Master Control Relay Area

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Program Control Instructions

Description: MCR(, )MCR

The following instructions turn the Master Control Relay function on and off:


Save RLO in MCR Stack, Begin MCR: MCR(
End MCR: )MCR You can nest MCR( and )MCR instructions. The maximum nesting depth is eight, that is, you can have a maximum of eight MCR( instructions in sequence before you insert an )MCR instruction. You must program an equal number of MCR( and )MCR instructions (see Figure 17-3). When MCR( instructions are nested, the MCR bit of the deeper nesting levels is formed. To form this MCR bit, the MCR( instruction combines the current RLO with the current MCR bit according to the And truth table. The )MCR instruction terminates a nesting level by restoring the MCR bit from the higher level. The )MCR instruction of the highest level sets the MCR bit to 1. If you use MCR( and )MCR in your program, you must always use them in pairs.

Example

Figure 17-2 shows how to implement a Master Control Relay. If the MCR bit is 1, then the MCR contact is closed. The signal states of outputs Q 4.0 and Q 4.1 are calculated according to the signal state of inputs I 1.0 to I 1.3 and their logic combinations. If the MCR bit is 0, then the MCR contact is opened. The outputs Q 4.0 and Q 4.1 are reset to 0, regardless of the signal states of inputs I 1.0 to I 1.3.

STL

Relay Logic Diagram

MCRA A I 2.0 MCR( O I 1.0 O I 1.1 = Q 4.0 A I 1.2 A I 1.3 = Q 4.1 )MCR MCRD

Power rail

MCR contact

I 2.0

I 1.0

I 1.2 I 1.3

Q 4.0

Q 4.1

MCR coil Master Control Relay implemented with the MCR( and )MCR instructions

Figure 17-2

I 1.1

Area which is controlled by the MCR (Master Control Relay), implemented with MCRA and MCRD instructions

Implementation of a Master Control Relay

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

17-13

Program Control Instructions

Figure 17-3 shows the nesting application of the instructions.

STL

MCRA A I 1.1 MCR ( A I 1.2 MCR ( A I 1.3 MCR (

S M 1.0 )MCR

S M 1.1 )MCR

Signal State

Result of Check

RLO

1

1

1

1

1

1

0

0

0

MCR Bit of Level 1 2 3

1 1 1 1

*

0 0 0 0 0

This bit (M 1.0) remains unchanged regardless of any previous logic string because the MCR bit = 0. 1 1 1 1

This bit (M 1.1) is changed due to the previous logic string and the function of the S instruction because the MCR = 1.

**

1 1 1 1

)MCR MCRD

*

The MCR bit of the deeper nesting level is formed. To form this MCR bit, the MCR( instruction combines the current RLO with the MCR bit of the current nesting level according to the And truth table.

**

When the )MCR instruction ends a nesting level, the instruction restores the MCR bit of the next higher level.

Figure 17-3

17-14

Nesting Application of MCR Instructions

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Program Control Instructions

Important Notes on Using MCR Functions Take care with blocks in which the Master Control Relay was activated with MCRA:


If the MCR is deactivated, the value 0 is written by all assignments in program segments between (MCR<) and (MCR>).


The MCR is deactivated if the RLO was =0 before an (MCR<) instruction.

!

Danger PLC in STOP or undefined runtime characteristics! The compiler also uses write access to local data behind the temporary variables defined in VAR_TEMP for calculating addresses. Formal parameter access
Access to components of complex FC parameters of the type STRUCT, UDT, ARRAY, STRING
Access to components of complex FB parameters of the type STRUCT, UDT, ARRAY, STRING from the IN_OUT area in a version 2 block.
Access to parameters of a version 2 function block if its address is greater than 8180.0.
Access in a version 2 function block to a parameter of the type BLOCK_DB opens DB0. Any subsequent data access sets the CPU to STOP. T 0, C 0, FC0 or FB0 are always used for TIMER, COUNTER, BLOCK_FC, and BLOCK_FB. Parameter passing


Calls in which parameters are transferred. KOP/FUP
T branches and midline outputs in Ladder or FBD starting with RLO=0.

Remedy: Free the above commands from their dependence on the MCR: 1. Deactivate the Master Control Relay using the Master Control Relay Deactivate instruction before the statement or network in question. 2. Activate the Master Control Relay again mit Master Control Relay Activate instruction after the statement or network in question.

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17-15

Program Control Instructions

17.6 Ending Blocks

Description

A Block End instruction is by itself a programming statement that terminates the scanning of a block. You can use either of the following types of Block End instructions to end a block:


Block End Unconditional (BEU): This instruction ends scanning in the current block and returns control to the block that called the one that has been terminated. When the program encounters a BEU instruction, it terminates the current block, regardless of the result of logic operation.


Block End Conditional (BEC): This instruction ends scanning in the current block and returns control to the block that called the one that has been terminated. When the program encounters a BEC instruction, it terminates the current block only if the result of logic operation is 1 (RLO = 1). If the RLO is 0, the program does not execute the Block End Conditional (BEC) statement. The RLO is set to 1 and program scanning continues within the current block.

17-16

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Appendix

Alphabetical Listing of Instructions

A

Programming Examples

B

Source Files – Examples and Reserved Key Words

C

References

D

Q-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions Chapter Overview

Section

Description

A.1

Listing with (German) SIMATIC and International Mnemonics

A.2

Alphabetical Listing with International Names

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A Page A-2 A-12

A-1

Alphabetical Listing of Instructions

A.1

Listing with (German) SIMATIC and International Mnemonics Table A-1 provides an alphabetical listing of the mnemonic abbreviations of the statement list instructions. Next to each German abbreviation are the equivalent international abbreviation, the full international name and the page on which the instruction is explained.

Table A-1

Alphabetical Listing with the SIMATIC and the International Mnemonic Abbreviations

SIMATIC Abbreviation

International Abbreviation

Name

Page No.

+

+

Add Integer Constant (8, 16, 32-Bit)

9-6

=

=

Assign

5-24

)

)

Nesting Closed

5-14

+AR1

+AR1

Add Accumulator 1 to Address Register 1

4-7

+AR2

+AR2

Add Accumulator 1 to Address Register 2

4-7

+D

+D

Add Accumulator 1 and Accumulator 2 as Double Integer (32-Bit)

9-2

-D

-D

Subtract Accumulator 1 and Accumulator 2 as Double Integer (32-Bit)

9-2

*D

*D

Multiply Accumulator 1 by Accumulator 2 as Double Integer (32-Bit)

9-2

/D

/D

Divide Accumulator 2 by Accumulator 1 as Doubel Integer (32-Bit)

9-2

==D

==D

Compare Double Integer (32-Bit) >, <, >=, <=, ==, <>

17-3

+I

+I

Add Accumulator 1 and Accumulator 2 as Integer (16-Bit)

9-2

-I

-I

Subtract Accumulator 1 from Accumulator 2 as Integer (16-Bit)

9-2

*I

*I

Multiply Accumulator 1 by Accumulator 2 as Integer (16-Bit)

9-2

/I

/I

Divide Accumulator 2 by Accumulator 1 as Integer (16-Bit)

9-2

==I

==I

Compare Integer (16-Bit) >, <, >=, <=, ==, <>

17-3

+R

+R

Add Accumulator 1 and Accumulator 2 as Real (32-Bit IEEE FP)

10-2

-R

-R

Subtract Accumulator 1 from Accumulator 2 as Real (32-Bit IEEE FP)

10-2

*R

*R

Multiply Accumulator 1 by Accumulator 2 as Real (32 Bit IEEE FP)

10-2

/R

/R

Divide Accumulator 2 by Accumulator 1 as Real (32-Bit IEEE FP)

10-2

==R

==R

Compare Real >, <, >=, <=, ==, <>

17-5

ABS

ABS

Absolute Value of a Real (32-Bit IEEE FP)

10-6

ACOS

ACOS

Arc Cosine of a Floating-Point Number (32-Bit IEEE FP)

10-7

ASIN

ASIN

Arc Sine of a Floating-Point Number (32-Bit IEEE FP)

10-7

ATAN

ATAN

Arc Tangent of a Floating-Point Number (32-Bit IEEE FP)

10-7

AUF

OPN

Call a Data Block

21-2

BEA

BEU

Block End Unconditional

17-16

BEB

BEC

Block End Conditional

17-16

BLD

BLD

Program Display Instruction

4-2

BTD

BTD

BCD to Double Integer (32-Bit)

18-4

BTI

BTI

BCD to Integer (16-Bit)

18-2

CALL

CALL

Call

17-3

A-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-1

Alphabetical Listing with the SIMATIC and the International Mnemonic Abbreviations, cont.

SIMATIC Abbreviation

International Abbreviation

Name

Page No.

CC

CC

Conditional Call

17-7

CLR

CLR

Clear RLO (= 0)

5-26

COS

COS

Cosine of a Floating-Point Number (32-Bit IEEE FP)

10-7

DEC

DEC

Decrement Accumulator 1

4-6

DTB

DTB

Double Integer (32-Bit) to BCD

12-6

DTR

DTR

Double Integer (32-Bit) to Real (32-Bit IEEE FP)

12-7

ENT

ENT

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3

4-3

EXP

EXP

Exponential Value of a Floating-Point Number (32-Bit IEEE FP) to Base E

FN

FN

Edge Negative

5-17

FP

FP

Edge Positive

5-16

FR

FR

Enable Counter (Free, FR C 0 to C 255)

6-5

FR

FR

Enable Timer (Free, FR T 0 to T 255)

7-3

INC

INC

Increment Accumulator 1

4-6

INVD

INVD

Ones Complement Double Integer (32-Bit)

12-14

INVI

INVI

Ones Complement Integer (16-Bit)

12-14

ITB

ITB

Integer (16-Bit) to BCD

12-5

ITD

ITD

Integer (16-Bit) to Double Integer (32-Bit)

12-6

L

L

Load

8-3

L

L

Load Length of Shared Data Block into Accumulator 1 (L DBLG)

8-12 15-2

L

L

Load Number of Shared Data Block into Accumulator 1 (L DBNO)

8-12

L

L

Load Length of Instance Data Block into Accumulator 1 (L DILG)

8-12 15-2

L

L

Load Number of Instance Data Block into Accumulator 1 (L DINO)

8-12 15-2

L

L

Load Status Word into Accumulator 1 (L STW)

8-6

L

L

Load Current Timer Value into Accumulator 1 as Integer (where the number of the current timer can be in the range of 0 to 255, for example: L T 32)

8-7

L

L

Load Current Counter Value into Accumulator 1 as Integer (where the number of the current counter can be in the range of 0 to 255, for example: L C 15)

7-6 8-8

LAR1

LAR1

Load Address Register 1 from Accumulator 1 (if no address is indicated)

8-11

LAR1

LAR1

Load Address Register 1 from ... (from address indicated)

8-11

LAR1

LAR1

Load Address Register 1 from Address Register 2 (LAR1 AR2)

8-11

LAR1

LAR1

Load Address Register 1 with Double Integer (32-Bit, LAR1 P#area byte.bit)

8-11

LAR2

LAR2

Load Address Register 2 from Accumulator 1 (if no address is indicated)

8-11

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

10-12

A-3

Alphabetical Listing of Instructions

Table A-1

Alphabetical Listing with the SIMATIC and the International Mnemonic Abbreviations, cont.

SIMATIC Abbreviation

International Abbreviation

Name

Page No.

LAR2

LAR2

Load Address Register 2 from ... (from address indicated)

8-11

LAR2

LAR2

Load Address Register 2 with Double Integer (32-Bit, LAR2 P#area byte.bit)

8-11

LC

LC

Load Current Counter Value into Accumulator 1 as BCD (where the number of the current counter can be in the range of 0 to 255, for example: LC C 15)

8-9

LC

LC

Load Current Timer Value into Accumulator 1 as BCD (where the number of the current timer can be in the range of 0 to 255, for example: LC T 32)

7-7 8-9

LEAVE

LEAVE

Accumulator 3 ---> Accumulator 2, Accumulator 4 ---> Accumulator 3

4-3

LN

LN

Natural Logarithm of a Floating-Point Number (32-Bit IEEE FP)

LOOP

LOOP

Loop

MCR(

MCR(

Save RLO in MCR Stack, Begin MCR

17-11

)MCR

MCR)

Restore RLO, End MCR

17-11

MCRA

MCRA

Activate MCR Area

17-11

MCRD

MCRD

Deactivate MCR Area

17-11

MOD

MOD

Division Remainder Double Integer (32-Bit)

9-5

NEGD

NEGD

Twos Complement Double Integer (32-Bit)

12-14

NEGI

NEGI

Twos Complement Integer (16-Bit)

12-14

NEGR

NEGR

Negate Real Number

12-14

NOP 0

NOP 0

Null Operation 0

NOP 1

NOP 1

Null Operation 1

4-2

NOT

NOT

Negate RLO

5-26

O

O

Or

5-10

O(

O(

Or with Nesting Open

5-14

OD

OD

Or Double Word (32-Bit)

13-6

ON

ON

Or Not

5-8

ON(

ON(

Or Not with Nesting Open

5-14

OW

OW

Or Word (16-Bit)

13-3

POP

POP

Accumulator 1 <--- Accumulator 2, Accumulator 2 <--- Accumulator 3, Accumulator 3 <--- Accumulator 4

4-2

PUSH

PUSH

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3, Accumulator 1 ---> Accumulator 2

4-2

R

R

Reset

5-22

R

R

Reset Counter (where the current counter can have a number in the range of 0 to 255, for example: R C 15)

6-5

R

R

Reset Timer (where the current timer can have a number in the range of 0 to 255, for example: R T 32)

7-4

RLD

RLD

Rotate Left Double Word (32-Bit)

14-8

RLDA

RLDA

Rotate Accumulator 1 Left via CC 1 (32-Bit)

14-6

A-4

10-11 16-8

4-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-1

Alphabetical Listing with the SIMATIC and the International Mnemonic Abbreviations, cont.

SIMATIC Abbreviation

International Abbreviation

Name

Page No.

RND

RND

Round

RND+

RND+

Round to Upper Double Integer

12-10

RND-

RND-

Round to Lower Double Integer

12-11

RRD

RRD

Rotate Right Double Word (32-Bit)

14-8

RRDA

RRDA

Rotate Accumulator 1 Right via CC 1 (32-Bit)

14-6

S

S

Set

5-21

S

S

Set Counter Preset Value (where the current counter can have a number in the range of 0 to 255, for example: S C 15)

7-3

SA

SF

Off-Delay Timer

6-15

SAVE

SAVE

Save RLO in BR Register

5-26

SE

SD

On-Delay Timer

6-11

SET

SET

Set RLO (= 1)

5-26

SI

SP

Pulse Timer

6-7

SIN

SIN

Sine of a Floating-Point Number (32-Bit IEEE FP)

10-7

SLD

SLD

Shift Left Double Word (32-Bit)

14-2

SLW

SLW

Shift Left Word (16-Bit)

14-2

SPA

JU

Jump Unconditional

16-3

SPB

JC

Jump if RLO = 1

16-4

SPBB

JCB

Jump if RLO = 1 with BR

16-4

SPBI

JBI

Jump if BR = 1

16-4

SPBIN

JNBI

Jump if BR = 0

16-4

SPBN

JCN

Jump if RLO = 0

16-4

SPBNB

JNB

Jump if RLO = 0 with BR

16-4

SPL

JL

Jump to Labels

16-3

SPM

JM

Jump if Minus

16-6

SPMZ

JMZ

Jump if Minus or 0

16-6

SPN

JN

Jump if Not 0

16-6

SPO

JO

Jump if OV = 1

16-5

SPP

JP

Jump if Plus

16-6

SPPZ

JPZ

Jump if Plus or 0

16-6

SPS

JOS

Jump if OS = 1

16-5

SPU

JUO

Jump if Unordered

16-6

SPZ

JZ

Jump if 0

16-6

SQR

SQR

Square of a Floating-Point Number (32-Bit IEEE PF)

10-9

SQRT

SQRT

Square Root of a Floating-Point Number (32-Bit IEEE PF)

10-9

SRD

SRD

Shift Right Double Word (32-Bit)

14-3

SRW

SRW

Shift Right Word (16-Bit)

14-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

12-9

A-5

Alphabetical Listing of Instructions

Table A-1

Alphabetical Listing with the SIMATIC and the International Mnemonic Abbreviations, cont.

SIMATIC Abbreviation

International Abbreviation

Name

Page No.

SS

SS

Retentive On-Delay Timer

6-13

SSD

SSD

Shift Sign Double Integer (32-Bit)

14-4

SSI

SSI

Shift Sign Integer (16-Bit)

14-4

SV

SE

Extended Pulse Timer

6-9

T

T

Transfer

8-3

T

T

Transfer Accumulator 1 to Status Word (T STW)

8-6

TAD

CAD

Change Byte Sequence in Accumulator 1 (32-Bit)

12-13

TAK

TAK

Toggle Accumulator 1 with Accumulator 2

4-2

TAN

TAN

Tangent of a Floating-Point Number (32-Bit IEEE FP)

10-7

TAR

CAR

Exchange Address Register 1 with Address Register 2

8-11

TAR1

TAR1

Transfer Address Register 1 to Accumulator 1 (if no address is indicated)

8-11

TAR1

TAR1

Transfer Address Register 1 to ... (to address indicated)

8-11

TAR1

TAR1

Transfer Address Register 1 to Address Register 2 (T AR1 AR2)

8-11

TAR2

TAR2

Transfer Address Register 2 to Accumulator 1 (if no address is indicated)

8-11

TAR2

TAR2

Transfer Address Register 2 to ... (to address indicated)

8-11

TAW

CAW

Change Byte Sequence in Accumulator 1 (16-Bit)

TDB

CDB

Exchange Shared Data Block and Instance Data Block

TRUNC

TRUNC

Truncate

U

A

And

5-10

U(

A(

And with Nesting Open

5-14

UC

UC

Unconditional Call

17-7

UD

AD

And Double Word (32-Bit)

13-6

UN

AN

And Not

5-8

UN(

AN(

And Not with Nesting Open

5-14

UW

AW

And Word (16-Bit)

13-3

X

X

Exclusive Or

5-10

X(

X(

Exclusive Or with Nesting Open

5-14

XN

XN

Exclusive Or Not

5-8

XN(

XN(

Exclusive Or Not with Nesting Open

5-14

XOD

XOD

Exclusive Or Double Word (32-Bit)

13-6

XOW

XOW

Exclusive Or Word (16-Bit)

13-3

ZR

CD

Counter Down

7-5

ZV

CU

Counter Up

7-5

A-6

12-13 15-2 12-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-2 provides an alphabetical listing of the mnemonic abbreviations of the statement list instructions. Next to each international abbreviation are the equivalent (German) SIMATIC abbreviation, the full international name and the page on which the instruction is explained. Table A-2

Alphabetical Listing with the International and the SIMATIC Mnemonic Abbreviations

International Abbreviation

SIMATIC Abbreviation

Name

Page No.

+

+

Add Integer Constant (8, 16, 32-Bit)

15-6

=

=

Assign

11-24

)

)

Nesting Closed

11-14

+AR1

+AR1

Add Accumulator 1 to Address Register 1

10-7

+AR2

+AR2

Add Accumulator 1 to Address Register 2

10-7

+D

+D

Add Accumulator 1 and Accumulator 2 as Double Integer (32-Bit)

15-2

-D

-D

Subtract Accumulator 1 from Accumulator 2 as Double Integer (32-Bit)

15-2

*D

*D

Multiply Accumulator 1 by Accumulator 2 as Double Integer (32-Bit)

15-2

/D

/D

Divide Accumulator 2 by Accumulator 1 as Double Integer (32-Bit)

15-2

==D

==D

Compare Double Integer (32-Bit) >, <, >=, <=, ==, <>

17-3

+I

+I

Add Accumulator 1 and Accumulator 2 as Integer (16-Bit)

15-2

-I

-I

Subtract Accumulator 1 from Accumulator 2 as Integer (16-Bit)

15-2

*I

*I

Multiply Accumulator 1 by Accumulator 2 as Integer (16-Bit)

15-2

/I

/I

Divide Accumulator 2 by Accumulator 1 as Integer (16-Bit)

15-2

==I

==I

Compare Integer (16-Bit) >, <, >=, <=, ==, <>

17-3

+R

+R

Add Accumulator 1 and Accumulator 2 as Real (32-Bit IEEE FP)

16-2

-R

-R

Subtract Accumulator 1 from Accumulator 2 as Real (32-Bit IEEE FP)

16-2

*R

*R

Multiply Accumulator 1 by Accumulator 2 as Real (32-Bit IEEE FP)

16-2

/R

/R

Divide Accumulator 2 by Accumulator 1 as Real (32-Bit IEEE FP)

16-2

==R

==R

Compare Real >, <, >=, <=, ==, <>

17-5

A

U

And

11-10

A(

U(

And with Nesting Open

11-14

ABS

ABS

Absolute Value of a Real (32-Bit IEEE FP)

16-6

ACOS

ACOS

Arc Cosine of a Floating-Point Number (32-Bit IEEE FP)

16-7

AD

UD

And Double Word (32-Bit)

19-6

AN

UN

And Not

11-9

AN(

UN(

And Not with Nesting Open

11-14

ASIN

ASIN

Arc Sine of a Floating-Point Number (32-Bit IEEE FP)

16-7

ATAN

ATAN

Arc Tangent of a Floating-Point Number (32-Bit IEEE FP)

16-7

AW

UW

And Word (16-Bit)

19-3

BEC

BEB

Block End Conditional

23-15

BEU

BEA

Block End Unconditional

23-15

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

A-7

Alphabetical Listing of Instructions

Table A-2

Alphabetical Listing with the International and the SIMATIC Mnemonic Abbreviations, cont.

International Abbreviation

SIMATIC Abbreviation

Name

Page No.

BLD

BLD

Program Display Instruction

10-2

BTD

BTD

BCD to Double Integer (32-Bit)

18-4

BTI

BTI

BCD to Integer (16-Bit)

18-2

CAD

TAD

Change Byte Sequence in Accumulator 1 (32-Bit)

18-13

CALL

CALL

Call

23-3

CAR

TAR

Exchange Address Register 1 with Address Register 2

14-11

CAW

TAW

Change Byte Sequence in Accumulator 1 (16-Bit)

18-13

CC

CC

Conditional Call

23-7

CD

ZR

Counter Down

13-5

CDB

TDB

Exchange Shared Data Block and Instance Data Block

21-2

CLR

CLR

Clear RLO (= 0)

11-26

COS

COS

Cosine of a Floating-Point Number (32-Bit IEEE FP)

16-7

CU

ZV

Counter Up

13-5

DEC

DEC

Decrement Accumulator 1

10-6

DTB

DTB

Double Integer (32-Bit) to BCD

18-6

DTR

DTR

Double Integer (32-Bit) to Real (32-Bit IEEE FP)

18-7

ENT

ENT

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3

10-3

EXP

EXP

Exponential Value of a Floating-Point Number (32-Bit IEEE FP) to base E

16-12

FN

FN

Edge Negative

11-17

FP

FP

Edge Positive

11-16

FR

FR

Enable Counter (Free, FR C 0 to C 255)

12-5

FR

FR

Enable Timer (Free, FR T 0 to T 255)

13-3

INC

INC

Increment Accumulator 1

10-6

INVD

INVD

Ones Complement Double Integer (32-Bit)

18-14

INVI

INVI

Ones Complement Integer (16-Bit)

18-14

ITB

ITB

Integer (16-Bit) to BCD

18-5

ITD

ITD

Integer (16-Bit) to Double Integer

18-6

JBI

SPBI

Jump if BR = 1

22-4

JC

SPB

Jump if RLO = 1

22-4

JCB

SPBB

Jump if RLO = 1 with BR

22-4

JCN

SPBN

Jump if RLO = 0

22-4

JL

SPL

Jump to Labels

22-3

JM

SPM

Jump if Minus

22-6

JMZ

SPMZ

Jump if Minus or 0

22-6

JN

SPN

Jump if Not 0

22-6

JNB

SPBNB

Jump if RLO = 0 with BR

22-4

A-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-2

Alphabetical Listing with the International and the SIMATIC Mnemonic Abbreviations, cont.

International Abbreviation

SIMATIC Abbreviation

Name

Page No.

JNBI

SPBIN

Jump if BR = 0

22-4

JO

SPO

Jump if OV = 1

22-5

JOS

SPS

Jump if OS = 1

22-5

JP

SPP

Jump if Plus

22-5

JPZ

SPPZ

Jump if Plus or 0

22-6

JU

SPA

Jump Unconditional

22-3

JUO

SPU

Jump if Unordered

22-6

JZ

SPZ

Jump if 0

22-6

L

L

Load

14-3

L

L

Load Length of Shared Data Block into Accumulator 1 (L DBLG)

14-12 21-2

L

L

Load Number of Shared Data Block into Accumulator 1 (L DBNO)

14-12

L

L

Load Length of Instance Data Block into Accumulator 1 (L DILG)

14-12 21-2

L

L

Load Number of Instance Data Block into Accumulator 1 (L DINO)

14-12 21-2

L

L

Load Status Word into Accumulator 1 (L STW)

14-6

L

L

Load Current Timer Value into Accumulator 1 as Integer (where the number of the current timer can be in the range of 0 to 255, for example: L T 32)

14-7

L

L

Load Current Counter Value into Accumulator 1 as Integer (where the number of the current counter can be in the range of 0 to 255, for example: L C 15)

13-6 14-8

LAR1

LAR1

Load Address Register 1 from Accumulator 1 (if no address is indicated)

14-11

LAR1

LAR1

Load Address Register 1 from ... (from address indicated)

14-11

LAR1

LAR1

Load Address Register 1 from Address Register 2 (LAR1 AR2)

14-11

LAR1

LAR1

Load Address Register 1 with Double Integer (32-Bit, LAR1 P#area byte.bit)

14-11

LAR2

LAR2

Load Address Register 2 from Accumulator 1 (if no address is indicated)

14-11

LAR2

LAR2

Load Address Register 2 from ... (from address indicated)

14-11

LAR2

LAR2

Load Address Register 2 with Double Integer (32-Bit, LAR2 P#area byte.bit)

14-11

LC

LC

Load Current Counter Value into Accumulator 1 as BCD (where the number of the current counter can be in the range of 0 to 255, for example: LC C 15)

14-9

LC

LC

Load Current Timer Value into Accumulator 1 as BCD (where the number of the current timer can be in the range of 0 to 255, for example: LC T 32)

13-7 14-10

LEAVE

LEAVE

Accumulator 3 ---> Accumulator 2, Accumulator 4 ---> Accumulator 3

10-3

LN

LN

Natural Logarithm of a Floating-Point Number (32-Bit IEEE FP)

16-11

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

A-9

Alphabetical Listing of Instructions

Table A-2

Alphabetical Listing with the International and the SIMATIC Mnemonic Abbreviations, cont.

International Abbreviation

SIMATIC Abbreviation

Name

Page No.

LOOP

LOOP

Loop

22-8

MCR(

MCR(

Save RLO in MCR Stack, Begin MCR

23-11

MCR)

)MCR

Restore RLO, End MCR

23-11

MCRA

MCRA

Activate MCR Area

23-11

MCRD

MCRD

Deactivate MCR Area

23-11

MOD

MOD

Division Remainder Double Integer (32-Bit)

15-5

NEGD

NEGD

Twos Complement Double Integer (32-Bit)

18-14

NEGI

NEGI

Twos Complement Integer (16-Bit)

18-14

NEGR

NEGR

Negate Real Number (32-Bit IEEE FP)

18-14

NOP 0

NOP 0

Null Operation 0

10-2

NOP 1

NOP 1

Null Operation 1

10-2

NOT

NOT

Negate RLO

11-26

O

O

Or

11-10

O(

O(

Or with Nesting Open

11-14

OD

OD

Or Double Word (32-Bit)

19-6

ON

ON

Or Not

11-9

ON(

ON(

Or Not with Nesting Open

11-14

OPN

AUF

Open a Data Block

21-2

OW

OW

Or Word (16-Bit)

19-3

POP

POP

Accumulator 1 <--- Accumulator 2, Accumulator 2 <--- Accumulator 3, Accumulator 3 <--- Accumulator 4

10-2

PUSH

PUSH

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3, Accumulator 1 ---> Accumulator 2

10-2

R

R

Reset

11-22

R

R

Reset Counter (where the current counter can have a number in the range of 0 to 255, for example: R C 15)

12-5

R

R

Reset Timer (where the current timer can have a number in the range of 0 to 255, for example: R T 32)

13-4

RLD

RLD

Rotate Left Double Word (32-Bit)

20-6

RLDA

RLDA

Rotate Accumulator 1 Left via CC 1 (32-Bit)

20-6

RND

RND

Round

18-9

RND+

RND+

Round to Upper Double Integer

18-10

RND-

RND-

Round to Lower Double Integer

18-11

RRD

RRD

Rotate Right Double Word (32-Bit)

20-8

RRDA

RRDA

Rotate Accumulator 1 Right via CC 1 (32-Bit)

20-6

S

S

Set

11-21

S

S

Set Counter Preset Value (where the current counter can have a number in the range of 0 to 255, for example: S C 15)

13-3

SAVE

SAVE

Save RLO in BR Register

11-26

A-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-2

Alphabetical Listing with the International and the SIMATIC Mnemonic Abbreviations, cont.

International Abbreviation

SIMATIC Abbreviation

Name

Page No.

SD

SE

On-Delay Timer

12-11

SE

SV

Extended Pulse Timer

12-9

SET

SET

Set RLO (= 1)

11-26

SF

SA

Off-Delay Timer

12-15

SIN

SIN

Sine of a Floating-Point Number (32-Bit IEEE FP)

16-7

SLD

SLD

Shift Left Double Word (32-Bit)

20-2

SLW

SLW

Shift Left Word (16-Bit)

20-2

SP

SI

Pulse Timer

12-7

SQR

SQR

Square of a Floating-Point Number (32-Bit IEEE PF)

16-9

SQRT

SQRT

Square Root of a Floating-Point Number (32-Bit IEEE PF)

16-9

SRD

SRD

Shift Right Double Word (32-Bit)

20-3

SRW

SRW

Shift Right Word (16-Bit)

20-2

SS

SS

Retentive On-Delay Timer

12-13

SSD

SSD

Shift Sign Double Integer (32-Bit)

20-4

SSI

SSI

Shift Sign Integer (16-Bit)

20-4

T

T

Transfer

14-3

T

T

Transfer Accumulator 1 to Status Word (T STW)

14-6

TAK

TAK

Toggle Accumulator 1 with Accumulator 2

10-2

TAN

TAN

Tangent of a Floating-Point Number (32-Bit IEEE FP)

16-7

TAR1

TAR1

Transfer Address Register 1 to Accumulator 1 (if no address is indicated)

14-11

TAR1

TAR1

Transfer Address Register 1 to ... (to address indicated)

14-11

TAR1

TAR1

Transfer Address Register 1 to Address Register 2 (T AR1 AR2)

14-11

TAR2

TAR2

Transfer Address Register 2 to Accumulator 1 (if no address is indicated)

14-11

TAR2

TAR2

Transfer Address Register 2 to ... (to address indicated)

14-11

TRUNC

TRUNC

Truncate

18-12

UC

UC

Unconditional Call

23-7

X

X

Exclusive Or

11-10

X(

X(

Exclusive Or with Nesting Open

11-14

XN

XN

Exclusive Or Not

11-9

XN(

XN(

Exclusive Or Not with Nesting Open

11-14

XOD

XOD

Exclusive Or Double Word (32-Bit)

19-6

XOW

XOW

Exclusive Or Word (16-Bit)

19-3

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

A-11

Alphabetical Listing of Instructions

A.2

Alphabetical Listing with International Names Table A-3 provides an alphabetical listing of the full international names of the statement list instructions. Next to each name is its international mnemonic abbreviation and the page on which the instruction is explained.

Table A-3

Statement List Instructions Arranged Alphabetically by International Full Name Name

Mnemonic Page No. Abbreviation

Absolute Value of a Real (32-Bit IEEE FP)

ABS

16-6

Accumulator 1 ---> Accumulator 2

PUSH

10-2

Accumulator 1 <--- Accumulator 2

POP

10-2

Accumulator 1 <--- Accumulator 2, Accumulator 2 <--- Accumulator 3, Accumulator 3 <--- Accumulator 4

POP

10-2

Accumulator 3 ---> Accumulator 2, Accumulator 4 ---> Accumulator 3

LEAVE

10-3

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3

ENT

10-3

Accumulator 3 ---> Accumulator 4, Accumulator 2 ---> Accumulator 3, Accumulator 1 ---> Accumulator 2

PUSH

10-2

Activate MCR Area

MCRA

23-11

Add Accumulator 1 and Accumulator 2 as Double Integer (32-Bit)

+D

15-2

Add Accumulator 1 and Accumulator 2 as Integer (16-Bit)

+I

15-2

Add Accumulator 1 and Accumulator 2 as Real (32-Bit IEEE FP)

+R

16-2

Add Accumulator 1 to Address Register 1

+AR1

10-7

Add Accumulator 1 to Address Register 2

+AR2

10-7

Add Integer Constant (8, 16, 32-Bit)

+

15-6

And

A

11-10

And Double Word (32-Bit)

AD

19-6

And Not

AN

11-9

And Not with Nesting Open

AN(

11-14

And with Nesting Open

A(

11-14

And Word (16-Bit)

AW

19-3

Arc Cosine of a Floating-Point Number (32-Bit IEEE FP)

ACOS

16-7

Arc Sine of a Floating-Point Number (32-Bit IEEE FP)

ASIN

16-7

Arc Tangent of a Floating-Point Number (32-Bit IEEE FP)

ATAN

16-7

Assign

=

11-24

BCD to Double Integer (32-Bit)

BTD

18-4

BCD to Integer (16-Bit)

BTI

18-2

Block End Conditional

BEC

23-15

Block End Unconditional

BEU

23-15

Call

CALL

23-3

Change Byte Sequence in Accumulator 1 (16-Bit)

CAW

18-13

Change Byte Sequence in Accumulator 1 (32-Bit)

CAD

18-13

A-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-3

Statement List Instructions Arranged Alphabetically by International Full Name, continued Name

Mnemonic Page No. Abbreviation

Clear RLO (= 0)

CLR

11-26

Compare Double Integer (32-Bit) >, <, >=, <=, ==, <>

==D

17-3

Compare Integer (16-Bit) >, <, >=, <=, ==, <>

==I

17-3

Compare Real >, <, >=, <=, ==, <>

==R

17-3

Conditional Call

CC

23-7

Cosine of a Floating-Point Number (32-Bit IEEE FP)

COS

16-7

Counter Down

CD

13-5

Counter Up

CU

13-5

Deactivate MCR Area

MCRD

23-11

Decrement Accumulator 1

DEC

10-6

Divide Accumulator 2 by Accumulator 1 as Double Integer (32-Bit)

/D

15-2

Divide Accumulator 2 by Accumulator 1 as Integer (16-Bit)

/I

15-2

Divide Accumulator 2 by Accumulator 1 as Real (32-Bit IEEE FP)

/R

16-2

Division Remainder Double Integer (32-Bit)

MOD

15-5

Double Integer (32-Bit) to BCD

DTB

18-6

Double Integer (32-Bit) to Real (32-Bit IEEE FP)

DTR

18-7

Edge Negative

FN

11-17

Edge Positive

FP

11-16

Enable Counter (Free, FR C 0 to C 255)

FR

12-5

Enable Timer (Free, FR T 0 to T 255)

FR

13-3

Exchange Address Register 1 with Address Register 2

CAR

14-11

Exchange Shared Data Block and Instance Data Block

CDB

21-2

Exclusive Or

X

11-10

Exclusive Or Double Word (32-Bit)

XOD

19-6

Exclusive Or Not

XN

11-9

Exclusive Or Not with Nesting Open

XN(

11-14

Exclusive Or with Nesting Open

X(

11-14

Exclusive Or Word (16-Bit)

XOW

19-3

Exponential Value of a Floating-Point Number (32-Bit IEEE FP) to base E

EXP

16-12

Extended Pulse Timer

SE

12-9

Increment Accumulator 1

INC

10-6

Integer (16-Bit) to BCD

ITB

18-5

Integer (16-Bit) to Double Integer

ITD

18-6

Jump if 0

JZ

22-6

Jump if BR = 0

JNBI

22-4

Jump if BR = 1

JBI

22-4

Jump if Minus

JM

22-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

A-13

Alphabetical Listing of Instructions

Table A-3

Statement List Instructions Arranged Alphabetically by International Full Name, continued Name

Mnemonic Page No. Abbreviation

Jump if Minus or 0

JMZ

22-6

Jump if Not 0

JN

22-6

Jump if OS = 1

JOS

22-5

Jump if OV = 1

JO

22-5

Jump if Plus

JP

22-6

Jump if Plus or 0

JPZ

22-6

Jump if RLO = 0

JCN

22-4

Jump if RLO = 0 with BR

JNB

22-4

Jump if RLO = 1

JC

22-4

Jump if RLO = 1 with BR

JCB

22-4

Jump if Unordered

JUO

22-6

Jump to Labels

JL

22-3

Jump Unconditional

JU

22-3

Load

L

14-3

Load Address Register 1 from ... (from address indicated)

LAR1

14-11

Load Address Register 1 from Accumulator 1 (if no address is indicated)

LAR1

14-11

Load Address Register 1 from Address Register 2 (LAR1 AR2)

LAR1

14-11

Load Address Register 1 with Double Integer (32-Bit, LAR1 P#area byte.bit)

LAR1

14-11

Load Address Register 2 from ... (from address indicated)

LAR2

14-11

Load Address Register 2 from Accumulator 1 (if no address is indicated)

LAR2

14-11

Load Address Register 2 with Double Integer (32-Bit, LAR2 P#area byte.bit)

LAR2

14-11

Load Current Counter Value into Accumulator 1 as Integer (where the number of the current counter can be in the range of 0 to 255, for example: L C 15)

L

13-6 14-8

Load Current Counter Value into Accumulator 1 as BCD (where the number of the current counter can be in the range of 0 to 255, for example: LC C 15)

LC

14-9

Load Current Timer Value into Accumulator 1 as BCD (where the number of the current timer can be in the range of 0 to 255, for example: LC T 32)

LC

13-7 14-10

Load Current Timer Value into Accumulator 1 as Integer (where the number of the current timer can be in the range of 0 to 255, for example: L T 32)

L

14-7

Load Length of Instance Data Block into Accumulator 1 (L DILG)

L

14-12 21-2

Load Length of Shared Data Block into Accumulator 1 (L DBLG)

L

14-12 21-2

Load Number of Instance Data Block into Accumulator 1 (L DINO)

L

14-12 21-2

Load Number of Shared Data Block into Accumulator 1 (L DBNO)

L

14-12 21-2

Load Status Word into Accumulator 1 (L STW)

L

14-6

Loop

LOOP

22-8

Multiply Accumulator 1 by Accumulator 2 as Double Integer (32-Bit)

*D

15-2

A-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Alphabetical Listing of Instructions

Table A-3

Statement List Instructions Arranged Alphabetically by International Full Name, continued Name

Mnemonic Page No. Abbreviation

Multiply Accumulator 1 by Accumulator 2 as Integer (16-Bit)

*I

15-2

Multiply Accumulator 1 by Accumulator 2 as Real (32-Bit IEEE FP)

*R

16-2

Natural Logarithm of a Floating-Point Number (32-Bit IEEE FP)

LN

16-11

Negate Real Number (32-Bit IEEE FP)

NEGR

18-14

Negate RLO

NOT

11-26

Nesting Closed

)

11-14

Null Operation 0

NOP 0

10-2

Null Operation 1

NOP 1

10-2

Off-Delay Timer

SF

12-15

On-Delay Timer

SD

12-11

Ones Complement Double Integer (32-Bit)

INVD

18-14

Ones Complement Integer (16-Bit)

INVI

18-14

Open a Data Block

OPN

21-2

Or

O

11-10

Or Double Word (32-Bit)

OD

19-6

Or Not

ON

11-9

Or Not with Nesting Open

ON(

11-14

Or with Nesting Open

O(

11-14

OR Word (16-Bit)

OW

19-3

Program Display Instruction

BLD

10-2

Pulse Timer

SP

12-7

Reset

R

11-22

Reset Counter (where the current counter can have a number in the range of 0 to 255, for example: R C 15)

R

12-5

Reset Timer (where the current timer can have a number in the range of 0 to 255, for example: R T 32)

R

13-4

Restore RLO, End MCR

)MCR

23-11

Retentive On-Delay Timer

SS

12-13

Rotate Accumulator 1 Left via CC 1 (32-Bit)

RLDA

20-8

Rotate Accumulator 1 Right via CC 1 (32-Bit)

RRDA

20-6

Rotate Left Double Word (32-Bit)

RLD

20-6

Rotate Right Double Word (32-Bit)

RRD

20-8

Round

RND

18-9

Round to Lower Double Integer

RND-

18-11

Round to Upper Double Integer

RND+

18-10

Save RLO in BR Register

SAVE

11-26

Save RLO in MCR Stack, Begin MCR

MCR(

23-11

Set

S

11-21

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

A-15

Alphabetical Listing of Instructions

Table A-3

Statement List Instructions Arranged Alphabetically by International Full Name, continued Name

Mnemonic Page No. Abbreviation

Set Counter Preset Value (where the current counter can have a number in the range of 0 to 255, for example: S C 15)

S

13-3

Set RLO (= 1)

SET

11-26

Shift Left Double Word (32-Bit)

SLD

20-2

Shift Left Word (16-Bit)

SLW

20-2

Shift Right Double Word (32-Bit)

SRD

20-3

Shift Right Word (16-Bit)

SRW

20-2

Shift Sign Double Integer (32-Bit)

SSD

20-4

Shift Sign Integer (16-Bit)

SSI

20-4

Sine of a Floating-Point Number (32-Bit IEEE FP)

SIN

16-7

Square of a Floating-Point Number (32-Bit IEEE PF)

SQR

16-9

Square Root of a Floating-Point Number (32-Bit IEEE PF)

SQRT

16-9

Subtract Accumulator 1 from Accumulator 2 as Double Integer (32-Bit)

-D

15-2

Subtract Accumulator 1 from Accumulator 2 as Integer (16-Bit)

-I

15-2

Subtract Accumulator 1 from Accumulator 2 as Real (32-Bit IEEE FP)

-R

16-2

Tangent of a Floating-Point Number (32-Bit IEEE FP)

TAN

16-7

Toggle Accumulator 1 with Accumulator 2

TAK

10-2

Transfer

T

14-3

Transfer Accumulator 1 to Status Word (T STW)

T

14-6

Transfer Address Register 1 to ... (to address indicated)

TAR1

14-11

Transfer Address Register 1 to Accumulator 1 (if no address is indicated)

TAR1

14-11

Transfer Address Register 1 to Address Register 2 (T AR1 AR2)

TAR1

14-11

Transfer Address Register 2 to ... (to address indicated)

TAR2

14-11

Transfer Address Register 2 to Accumulator 1 (if no address is indicated)

TAR2

14-11

Truncate

TRUNC

18-12

Twos Complement Double Integer (32-Bit)

NEGD

18-14

Twos Complement Integer (16-Bit)

NEGI

18-14

Unconditional Call

UC

23-7

A-16

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B

Programming Examples Chapter Overview

Section

Description

Page

B.1

Overview

B-2

B.2

Bit Logic Instructions

B-3

B.3

Timer Instructions

B.4

Counter and Comparison Instructions

B-10

B.5

Integer Math Instructions

B-12

B.6

Word Logic Instructions

B-14

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B-7

B-1

Programming Examples

B.1

Overview

Practical Applications

Each statement list instruction described in this manual triggers a specific operation. When you combine these instructions into a program, you can accomplish a wide variety of automation tasks. This chapter provides the following examples of practical applications of the statement list instructions:


Controlling a conveyor belt using bit logic instructions
Detecting direction of movement on a conveyor belt using bit logic instructions


Generating a clock pulse using timer instructions
Keeping track of storage space using counter and comparison instructions
Solving a problem using integer math instructions
Setting the length of time for heating an oven When you create an ASCII file that will be imported into the STL editor, you must follow the conventions outlined in Appendix C.

Instructions Used

The examples in this chapter use the following instructions:


And (A) and And Not (AN)
Assign (=)
Block End (BE) and Block End Conditional (BEC)
Compare Integer (16-bit, <=, >=)
Counter Down (CD) and Counter Up (CU)
Edge Positive (FP)
Extended Pulse Timer (SE)
Increment Accumulator 1 (INC)
Integer Four-function Math (16 BITS) – Add Accumulators 1 and 2 As Integer (+I) – Divide Accumulator 2 by Accumulator 1 As Integer (/I) – Multiply Accumulators 1 and 2 As Integers (I)


Load (L) and Transfer (T)
Negate RLO (NOT)
Or (O) and Or Not (ON)
Set (S) and Reset (R)
Word Logic (And Word, Or Word)

B-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

B.2

Bit Logic Instructions

Controlling a Conveyor Belt

Figure B-1 shows a conveyor belt that can be activated electrically. There are two push button switches at the beginning of the belt: S1 for START and S2 for STOP. There are also two push button switches at the end of the belt: S3 for START and S4 for STOP. It it possible to start or stop the belt from either end. Also, sensor S5 stops the belt when an item on the belt reaches the end.

Symbolic Programming

You can write a program to control the conveyor belt shown in Figure B-1 using symbols that represent the various components of the conveyor system. If you choose this method, you need to make a symbol table to correlate the symbols you choose with absolute values (see Table B-1). Table B-3 compares a statement list program that uses symbols as addresses to a program that uses absolute values as addresses. You define the symbols in the symbol table (see STEP 7 Online Help). Table B-1

Elements of Symbolic Programming for Conveyor Belt System

System Component

Absolute Address

Push Button Start Switch

I 1.1

S1

I 1.1

S1

Push Button Stop Switch

I 1.2

S2

I 1.2

S2

Push Button Start Switch

I 1.3

S3

I 1.3

S3

Push Button Stop Switch

I 1.4

S4

I 1.4

S4

Sensor

I 1.5

S5

I 1.5

S5

Motor

Q 4.0

MOTOR_ON

Q 4.0

MOTOR_ON

Symbol

Symbol Table

Sensor S5

MOTOR_ON Figure B-1

S1 S2


Start
Stop

S3 S4


Start
Stop

Conveyor Belt System

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B-3

Programming Examples

Absolute Programming

You can write a program to control the conveyor belt shown in Figure B-1 using absolute values that represent the different components of the conveyor system (see Table B-2). Table B-3 compares a statement list program that uses absolute values as addresses to a program that uses symbols as addresses. An explanation of the program follows the tables. Table B-2

Elements of Absolute Programming for Conveyor Belt System System Component

Push Button Start Switch

I 1.1

Push Button Stop Switch

I 1.2

Push Button Start Switch

I 1.3

Push Button Stop Switch

I 1.4

Sensor

I 1.5

Motor

Q 4.0

Table B-3

Symbolic and Absolute Programs to Control a Conveyor Belt Symbolic Program O O S O O ON R

STL O O S O O ON R

B-4

Absolute Address

S1 S3 MOTOR_ON S2 S4 S5 MOTOR_ON

Absolute Program O O S O O ON R

I 1.1 I 1.3 Q 4.0 I 1.2 I 1.4 I 1.5 Q 4.0

Explanation I I Q I I I Q

1.1 1.3 4.0 1.2 1.4 1.5 4.0

Pressing either start switch turns the motor on.

Pressing either stop switch or opening the normally closed contact at the end of the belt turns the motor off.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

Detecting the Direction of a Conveyor Belt

Figure B-2 shows a conveyor belt that is equipped with two photoelectric barriers (PEB1 and PEB2) that are designed to detect the direction in which a package is moving on the belt. Each photoelectric light barrier functions like a normally open contact (see Section 5.1).

Symbolic Programming

You can write a program to activate a direction display for the conveyor belt system shown in Figure B-2 using symbols that represent the various components of the conveyor system, including the photoelectric barriers that detect direction. If you choose this method, you need to make a symbol table to correlate the symbols you choose with absolute values (see Table B-4). Table B-6 compares a statement list program that uses symbols as addresses to a program that uses absolute values as addresses. You define the symbols in the symbol table (see the STEP 7 Online Help). Table B-4

Elements of Symbolic Programming for Detecting Direction

System Component

Q 4.0

Figure B-2

Absolute Address

Symbol

Symbol Table

Photo electric barrier 1

I 0.0

PEB1

I 0.0

PEB1

Photo electric barrier 2

I 0.1

PEB2

I 0.1

PEB2

Display for movement to right

Q 4.0

RIGHT

Q 4.0

RIGHT

Display for movement to left

Q 4.1

LEFT

Q 4.1

LEFT

Pulse memory bit 1

M 0.0

PMB1

M 0.0

PMB1

Pulse memory bit 2

M 0.1

PMB2

M 0.1

PMB2

PEB2

PEB1

Q 4.1

Conveyor Belt System with Photoelectric Light Barriers for Detecting Direction

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B-5

Programming Examples

Absolute Programming

You can write a program to control the direction display for the conveyor belt shown in Figure B-2 using absolute values that represent the photoelectric barriers that detect direction (see Table B-5). Table B-6 compares a statement list program that uses absolute values as addresses to a program that uses symbols as addresses. An explanation of the program follows the figure. Table B-5

Elements of Absolute Programming for Detecting Direction System Component

Photo electric barrier 1

I 0.0

Photo electric barrier 2

I 0.1

Display for movement to right

Q 4.0

Display for movement to left

Q 4.1

Pulse memory bit 1

M 0.0

Pulse memory bit 2

M 0.1

Table B-6

Symbolic and Absolute Programs to Detect Direction Symbolic Program A FP AN S A FP AN S AN AN R R

STL

Absolute Address

I PEB1 PMB1 PEB2 LEFT PEB2 PMB2 PEB1 RIGHT PEB1 PEB2 RIGHT LEFT

Absolute Program A FP AN S A FP AN S AN AN R R

I 0.0 M 0.0 I 0.1 Q 4.1 I 0.1 M 0.1 I 0.0 Q 4.0 I 0.0 I 0.1 Q 4.0 Q 4.1

Explanation

A FP AN S

I M I Q

0.0 0.0 0.1 4.1

If there is a transition in signal state from 0 to 1 (positive edge) at input I 0.0 and, at the same time, the signal state at input I 0.1 is 0, then the package on the belt is moving to the left.

A FP AN S

I M I Q

0.1 0.1 0.0 4.0

AN AN R R

I I Q Q

0.0 0.1 4.0 4.1

If there is a transition in signal state from 0 to 1 (positive edge) at input I 0.1 and, at the same time, the signal state at input I 0.0 is 0, then the package on the belt is moving to the right. If one of the photoelectric light barriers is broken, this means that there is a package between the barriers.

B-6

If neither photoelectric barrier is broken, then there is no package between the barriers. The direction pointer shuts off.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

B.3

Timer Instructions

Clock Pulse Generator

You can use a clock pulse generator or flasher relay when you need to produce a signal that repeats periodically. A clock pulse generator is common in a signalling system that controls the flashing of indicator lamps. When you use the S7-300, you can implement the clock pulse generator function by using time-driven processing in special organization blocks. The example shown in the following statement list program, however, illustrates the use of timer functions to generate a clock pulse. The following example shows how to implement a freewheeling clock pulse generator by using a timer (pulse duty factor 1:1). The frequency is divided into the values listed in Table B-7.

STL AN L SE NOT BEC L INC T

Explanation T 1 S5T#250ms T 1

MB100 1 MB100

If timer T 1 has expired, load the time value 250 ms into T 1 and start T 1 as an extended-pulse timer. Negate (invert) the result of logic operation. If the timer is running, end the current block. If the timer has expired, load the contents of memory byte MB100, increment the contents by 1, and transfer the result to memory byte MB100.

A signal check of timer T 1 produces the result of logic operation.

1 0 250 ms Figure B-3

RLO for AN T 1 Statement in the Clock Pulse Timer Example

As soon as the time runs out, the timer is restarted. Therefore, the signal check made by the statement AN T 1 produces a signal state of 1 only briefly.

1 0 250 ms Figure B-4

Negated RLO Bit of Timer T 1 in the Clock Pulse Timer Example

Every 250 ms the RLO bit is 0. Figure B-4 shows what the negated (inverted) RLO bit looks like. Then the BEC statement does not end the processing of the block. Instead, the contents of memory byte MB100 is incremented by 1. The contents of memory byte MB100 changes every 250 ms as follows: 0 !1!2!3! ... !254!255!0!1 ...

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B-7

Programming Examples

Achieving a Specific Frequency

Table B-7 lists the frequencies that you can achieve from the individual bits of memory byte MB100. The statement list program that follows the table shows how you can use the frequencies that are generated. Table B-7 Bits of MB100

STL A A =

B-8

Frequencies for Clock Pulse Timer Example Frequency in Hertz

Duration

M 100.0

2.0

0.5 s (250 ms on/250 ms off)

M 100.1

1.0

1 s (0.5 s on/0.5 s off)

M 100.2

0.5

2 s (1 s on/1 s off

M 100.3

0.25

4 s (2 s on/2 s off)

M 100.4

0.125

8 s (4 s on/4 s off)

M 100.5

0.0625

16 s (8 s on/8 s off)

M 100.6

0.03125

32 s (16 s on/16 s off)

M 100.7

0.015625

64 s (32 s on/32 s off)

Explanation M 10.0 M 100.1 Q 4.0

M 10.0 = 1 when a fault occurs. The fault lamp blinks at a frequency of 1 Hz when a fault occurs.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

Table B-8 lists the signal states of the bits of memory byte MB100. Figure B-5 shows the RLO of memory bit M100.1. Table B-8

Signal States of the Bits of Memory Byte MB100

7

6

5

4

3

2

1

0

Time Value in ms

0

0

0

0

0

0

0

0

0

250

1

0

0

0

0

0

0

0

1

250

2

0

0

0

0

0

0

1

0

250

3

0

0

0

0

0

0

1

1

250

4

0

0

0

0

0

1

0

0

250

5

0

0

0

0

0

1

0

1

250

6

0

0

0

0

0

1

1

0

250

7

0

0

0

0

0

1

1

1

250

8

0

0

0

0

1

0

0

0

250

9

0

0

0

0

1

0

0

1

250

10

0

0

0

0

1

0

1

0

250

11

0

0

0

0

1

0

1

1

250

12

0

0

0

0

1

1

0

0

250

Scan Cycle

Signal State of Bits of Memory Byte MB100

T M 100.1

1 0 Time 0

250 ms 0.5 s 0.75 s 1 s 1.25 s 1.5 s

Frequency
1
1
1Hz 1 s T Figure B-5

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Signal State of Bit 1 MB100 (M 100.1)

B-9

Programming Examples

B.4

Counter and Comparison Instructions

Storage Area with Counter and Comparator

Figure B-6 shows a system with two conveyor belts and a temporary storage area in between them. Conveyor belt 1 delivers packages to the storage area. A photoelectric barrier at the end of conveyor belt 1 near the storage area determines how many packages are delivered to the storage area. Conveyor belt 2 transports packages from the temporary storage area to a loading dock where trucks take the packages away for delivery to customers. A photoelectric barrier at the end of conveyor belt 2 near the storage area determines how many packages leave the storage area to go to the loading dock. A display panel with five lamps indicates the fill level of the temporary storage area. The sample program that follows Figure B-6 is the program that activates the indicator lamps on the display panel.

Display Panel

Storage area empty

Storage area not empty

Storage area 50% full

Storage area 90% full

(Q 4.0)

(Q 4.1)

(Q 4.2)

(Q 4.3)

I 0.0 Packages in

Temporary storage for 100 packages

Conveyor belt 1

B-10

(Q 4.4)

I 0.1 Packages out

Conveyor belt 2 Photoelectric barrier 1

Figure B-6

Storage area filled to capacity

Photoelectric barrier 2

Storage Area with Counter and Comparator

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

STL

Explanation

A I 0.0 CU C 1 A CD

I 0.1 C 1

AN = A = L L <=I = L >=I = L L >=I =

C 1 Q 4.0 C 1 Q 4.1 +50 C 1

Each pulse generated by photoelectric barrier 1 increases the count value of counter C 1 by one, thereby counting the number of packages going into the storage area. Each pulse generated by photoelectric barrier 2 decreases the count value of counter C 1 by one, thereby counting the packages that leave the storage area. If the count value is 0, the indicator lamp for “Storage area empty” comes on. If the count value is not 0, the indicator lamp for “Storage area not empty” comes on. If 50 is less than or equal to the count value, the indicator lamp for “Storage area 50% full” comes on.

Q 4.2 +90

If the count value is greater than or equal to 90, the indicator lamp for “Storage area 90% full” comes on.

Q 4.3 C 1 100

If the count value is greater than or equal to 100, the indicator lamp for “Storage area filled to capacity” comes on. (You could also use output Q 4.4 to lock conveyor belt 1.)

Q 4.4

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

B-11

Programming Examples

B.5

Integer Math Instructions

Solving a Math Problem

The following sample program (applicable for the S7-300 only) shows you how to use three integer math instructions, along with Load and Transfer, to produce the same result as the following equation: MD4 +

STL L L

IW0 DB5.DBW3

+15

I

L

MW2

/I

T

B-12

15

Explanation

+I

L

(IW0 ) DBW3) MW2

MD4

Load the value from input word IW0 into accumulator 1. Load the value from shared data word DBW3 of DB5 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. Add the contents of the low words of accumulators 1 and 2. The result is stored in the low word of accumulator 1. The contents of accumulator 2 and the high word of accumulator 1 remain unchanged. Load the constant value +15 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. Multiply the contents of the low word of accumulator 2 by the contents of the low word of accumulator 1. The result is stored in accumulator 1. The contents of accumulator 2 remain unchanged. Load the value from memory word MW2 into accumulator 1. The old contents of accumulator 1 are shifted to accumulator 2. Divide the contents of the low word of accumulator 2 by the contents of the low word of accumulator 1. The result is stored in accumulator 1. The contents of accumulator 2 remain unchanged. Transfer the final result to memory double word MD4. The contents of both accumulators remain unchanged.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Programming Examples

Figure B-7 shows the relationship of the program to the equation.

Accumulator 1

Accumulator 2

L

IW0

(IW0)

³

(Old contents)

L

DBW3

(DBW3) + ± (IW0) + (DBW3)

³

(IW0)

+I

L

+15

I

L

MW2

/I

T

MD4

15  ± [(IW0) + (DBW3)] 15

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

³

(IW0) + (DBW3)

(IW0) + (DBW3)

³

MW2 / ±

[(IW0) + (DBW3)] 15

(IW0 ) DBW3) MW2

15

(IW0 ) DBW3)

15

(IW0 ) DBW3) MW2

15

(IW0 ) DBW3)

15

MD4 +

Figure B-7

(IW0)

(IW0 ) DBW5) MW2

15

Relationship of Integer Math Statements to an Equation (S7-300)

B-13

Programming Examples

B.6

Word Logic Instructions

Heating an Oven

The operator of the oven shown in Figure B-8 starts the oven heating by pushing the start push button. The operator can set the length of time for heating by using the thumbwheel switches shown in the figure. The value that the operator sets indicates seconds in binary coded decimal (BCD) format. Table B-9 lists the components of the heating system and their corresponding absolute addresses used in the sample program that follows Figure B-8. Table B-9

Heating System Components and Corresponding Absolute Addresses System Component

Absolute Address in STL Program

Start push button

I 0.7

Thumbwheel for ones

I 1.0 to I 1.3

Thumbwheel for tens

I 1.4 to I 1.7

Thumbwheel for hundreds

I 0.0 to I 0.3

Heating starts

Q 4.0

Thumbwheels for setting BCD digits

ÎÎÎÎÎ ÎÎÎÎÎ

Oven

4 Heat Q 4.0

7....

...0

XXXX

0001

4

4

7... 1001

IB0

...0

Bits

0001

IW0

IB1

Bytes

Start push button I 0.7

Figure B-8

Using the Inputs and Outputs for the Time-Limited Heating Process

STL

Explanation

A T 1 = Q 4.0 BEC

If the timer is running, then turn on the heat.

L AW

IW0 W#16#0FFF

OW

W#16#2000

A SE BE

I 0.7 T 1

B-14

If the timer is running, then end processing here. This prevents timer T 1 from being restarted if the push button is pressed. Mask input bits I 0.4 through I 0.7 (that is, reset them to 0). The time value in seconds is in the low word of accumulator 1 in binary coded decimal format. Assign the time base as seconds in bits 12 and 13 of the low word of accumulator 1. Start timer T 1 as an extended pulse timer if the push button is pressed. End the program network.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

C

Source Files - Examples and Reserved Keywords

Definition

A keyword is a reserved identifier which cannot be used as a general identifier. To use a keyword as a global symbol it must be marked as scan cycle checkpoint (SCC). To use a keyword as a local symbol it must be marked with #.

Overview

Table C-1 lists all keywords reserved for STEP 7. Table C-1

Keywords Keywords

A

B

AB

BEGIN

AD

BIE

ANY

BLOCK_DB

AO

BLOCK_FB

AR1

BLOCK_FC

AR2

BLOCK_SDB

ARRAY

BOOL

AUTHOR

BYTE

AW

C

DATA_BLOCK

CALL

DATE

CHAR

DATE_AND_TIME

COUNTER

DB DBB DBD DBLG DBNO DBW DBX

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

C-1

Source Files – Examples and Reserved Keywords

Table C-1

Keywords, continued Keywords DI DIB DID DILG DINO DINT DIW DIX DT DWORD

E

FALSE

EB

FAMILY

ED

FB

END_Data_Block

FC

END_Function

FUNCTION

END_Function_Block

FUNCTION_BLOCK

END_Organization_Block END_Struct

I

END_System_Function

IB

END_System_Function_Block

ID

END_Type

INT

END_VAR

IW

EW

KA

L

KNOW_HOW_PROTECT

LB

KP

LD LW

C-2

M

NAME

MB

NETWORK

MD

NI

MW

NO

OB

PA

OF

PAB

ORGANIZATION_BLOCK

PAD

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Source Files – Examples and Reserved Keywords

Table C-1

Keywords, continued Keywords

OS

PAW

OV

PE PEB PED PEW PI PIB PID PIW PQ PQB PQD PQW POINTER

Q

READ_ONLY

QB

REAL

QD

RET_VAL

QW

S5T

T

S5TIME

TIME

SDB

TIME_OF_DAY

SFB

TIMER

SFC

TITLE

STANDARD

TOD

STRING

TRUE

STRUCT

TYPE

STW SYSTEM_FUNCTION SYSTEM_FUNCTION_BLOCK

UDT

VAR

UNLINKED

VAR_IN_OUT

UO

VAR_INPUT VAR_OUTPUT VAR_TEMP VERSION

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

C-3

Source Files – Examples and Reserved Keywords

Table C-1

Keywords, continued Keywords VOID

WORD

C-4

Z

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

D

References /30/

Getting Started: Working with STEP 7 V5.0

/70/

Manual: S7-300 Programmable Controller, Hardware and Installation

/71/

Reference Manual: S7-300, M7-300 Programmable Controllers Module Specifications

/72/

Instruction List: S7-300 Programmable Controller

/100/ Manual: S7-400/M7-400 Programmable Controllers, Hardware and Installation /101/ Reference Manual: S7-400/M7-400 Programmable Controllers Module Specifications /102/ Instruction List: S7-400 Programmable Controller /231/ Manual: Configuring Hardware and Communication Connections, STEP 7 V5.0 /233/ Reference Manual: Ladder Logic (LAD) for S7-300 and S7-400 Programming /234/ Manual: Programming with STEP 7 V5.0 /235/ Reference Manual: System Software for S7-300 and S7-400 System and Standard Functions /236/ Reference Manual: Function Block Diagram (FBD) for S7-300 and 400, Programming /250/ Manual: Structured Control Language (SCL) for S7-300/S7-400, Programming /251/ Manual: S7-GRAPH for S7-300 and S7-400, Programming Sequential Control Systems /252/ Manual: S7-HiGraph for S7-300 and S7-400, Programming State Graphs /253/ Manual: C Programming for S7-300 and S7-400, Writing C Programs /254/ Manual: Continuous Function Charts (CFC) for S7 and M7, Programming Continuous Function Charts /270/ Manual: S7-PDIAG for S7-300 and S7-400 “Configuring Process Diagnostics for LAD, STL, and FBD” /271/ Manual: NETPRO, “Configuring Networks” Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

D-1

References

/800/ DOCPRO Creating Wiring Diagrams (CD only) /801/ TeleService for S7, C7 and M7 Remote Maintenance for Automation Systems (CD only) /802/ PLC Simulation for S7-300 and S7-400 (CD only) /803/ Reference Manual: Standard Software for S7-300 and S7-400, STEP 7 Standard Functions, Part 2

D-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary

A Absolute Addressing

In absolute addressing, the memory location of the address to be processed is given.

Accumulator

Accumulators are registers in the CPU which act as intermediate buffers for load, transfer, comparison, math, and conversion operations.

Actual Parameter

Actual parameters replace the formal parameters when function blocks (FBs) and functions (FCs) are called. Example: The formal parameter “Start” is replaced by the actual parameter “I3.6”.

Address

An address is part of a STEP 7 statement and specifies what the processor should execute the instruction on. Addresses can be absolute or symbolic.

Address Identifier

An address identifier is the part of the address which contains various data. The data can include elements such as a value itself (data object) or the size of a value with which the instruction can, for example, perform a logic operation. In the instruction statement “L IB10” IB is the address identifier (“I” indicates the memory input area and “B” indicates a byte in that area).

Address Register

The address register is part of the registers in the communication part of the CPU. They act as pointers for register indirect addressing (possible in STL).

Array

An array is a complex data type which consists of data elements of the same type. These data elements can be elementary or complex.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary-1

Glossary

B Bit Result (BR)

The bit result is the link between bit and word-oriented processing. This is an efficient method to allow the binary interpretation of the result of a word instruction and to include it in a series of logic operations.

C Call Hierarchy

All blocks must be called first before they can be processed. The sequence and nesting of these calls within an organized block is called the call hierarchy.

Condition Codes CC 1 and CC 0

The CC 1 and CC 0 bits (condition codes) provide information on the following results or bits:


Result of a math operation
Result of a comparison
Result of a digital operation
Bits that have been shifted out by a shift or rotate command CPU

A CPU (central processing unit) is the central module in a programmable controller in which the user program is stored and processed. It consists of an operating system, processing unit, and communication interfaces.

Current Path

Characteristic of the Ladder Logic programming language. Current paths contain contacts and coils. Complex elements (for example, math functions) can also be inserted into current paths in the form of “boxes.” Current paths are connected to power rails.

D Data Block (DB)

Glossary-2

Data blocks (DBs) are areas in a user program which store user data. There are shared data blocks which can be accessed by all logic blocks and there are instance data blocks which are associated with a certain function block (FB) call. In contrast to all other blocks, data blocks do not contain instructions.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary

Data, Static

Static data are local data of a function block which are stored in the instance data block and, therefore, remain intact until the function block is processed again.

Data Type

A data type defines how the value of a variable or a constant should be used in the user program. In SIMATIC STEP 7 two data types are available to the user (IEC 1131–3):


Elementary data types
Complex data types Data Type, Complex

Complex data types are created by the user with the data type declaration. They do not have their own name and cannot, therefore, be used again. They can either be arrays or structures. The data types STRING and DATE AND TIME are classed as complex data types.

Data Type, Elementary

Elementary data types are preset data types according to IEC 1131–3. Examples:


Data type “BOOL” defines a binary variable (“Bit”)
Data type “INT” defines a 16-bit fixed-point variable.

Declaration

The declaration section is used for the declaration of the local data of a logic block when programming in the Text Editor.

Direct Addressing

In direct addressing, the address contains the memory location of a value which is to be used by the instruction. Example: The location Q4.0 defines bit 0 in byte 4 of the process-image output table.

F First Check Bit

First check of the result of logic operation.

Folder

Directory of the user interface of the SIMATIC Manager which can be opened and can hold other directories or objects.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary-3

Glossary

Formal Parameter

A formal parameter is a placeholder for the actual parameter in logic blocks. In function blocks (FBs) and functions (FCs) the formal parameters are declared by the user, in system function blocks (SFBs) and system functions (SFCs) they are already available. When a block is called, formal parameters are assigned actual parameters, so the called block works with the current values. The formal parameters are classed as local data. They can be input, output, or in/out parameters.

Function (FC)

According to the International Electrotechnical Commission’s IEC 1131–3 standard, functions are logic blocks without a ‘memory’ (meaning they do not have static data). A function allows you to transfer parameters in the user program, which means they are suitable for programming frequently recurring, complex functions, such as calculations. Important: As a function has no memory, you must continue processing the calculated values directly after the function has been called.

Function Block (FB)

According to the International Electrotechnical Commission’s IEC 1131–3 standard, function blocks are logic blocks with a ‘memory’ (meaning they have static data). A function block allows you to transfer parameters in the user program, which means they are suitable for programming frequently recurring, complex functions, such as closed-loop control and operating mode selection. As a function block has a memory (instance data block), you can access its parameters (for example, outputs) at any time and at any point in the user program.

Function Block Diagram (FBD)

Function Block Diagram (FBD) is one of the programming languages in STEP 5 and STEP 7. FBD represents logic in the boxes familiar from Boolean algebra. In addition, complex functions (for example, math functions) can be represented in direct connection with the logic box. Programs created with FBD can also be translated into other programming languages (for example, Ladder Logic).

I Immediate Addressing

In immediate addressing, the address contains the value with which the instruction works. Example: L.27 means load constant 27 into accumulator.

Input, Incremental

Glossary-4

When a block is input incrementally, each line or element is checked immediately for errors (for example, syntax errors). If an error is detected, it is marked and must be corrected before programming is completed. Incremental input is possible in STL (Statement List), LAD (Ladder Logic), and FBD (Function Block Diagram).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary

Instance

An “instance” is the call of a function block. An instance data block is assigned to each call.

Instance Data Block (DB)

An instance data block stores the formal parameters and the static data of function blocks. An instance data block can be assigned to one function block call or a call hierarchy of function blocks.

Instruction

An instruction is part of a STEP 7 statement; it specifies what the processor should do.

K Keyword

Keywords are used when programming with source files to identify the start and end of a block and to select sections in the declaration section of blocks, the start of block comments and the start of titles.

L Ladder Logic (LAD)

Ladder Logic is a graphic programming language in STEP 5 and STEP 7. Its representation is standardized in compliance with DIN 19239 (international standard IEC 1131-1). Ladder Logic representation corresponds to the representation of relay ladder logic diagrams. In contrast to Statement List (STL), LAD has a restricted set of instructions.

Logic Block

Logic blocks are blocks within SIMATIC S7 that contain a part of the STEP 7 user program. In contrast, data blocks (DBs) only contain data. There are the following types of logic blocks: organization blocks (OBs), function blocks (FBs), functions (FCs), system function blocks (SFBs), and system functions (SFCs). Blocks are stored in the “Blocks” folder under the “S7 Program” folder.

Logic String

A logic string is that portion of a user program which begins with an FC bit that has a signal state of 0 and which ends when an instruction or event resets the FC bit to 0. When the CPU executes the first instruction in a logic string, the FC bit is set to 1. Certain instructions such as output instructions (for example, Set, Reset, or Assign) reset the FC bit to 0. See First Check Bit above.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary-5

Glossary

M Master Control Relay

The Master Control Relay (MCR) is an American relay ladder logic master switch for energizing and de-energizing power flow (current path). A de-energized current path corresponds to an instruction sequence that writes a zero value instead of the calculated value, or, to an instruction sequence that leaves the existing memory value unchanged.

Memory Area

In SIMATIC S7 a CPU has three memory areas:


Load memory
Work memory
System memory Memory Indirect Addressing

A type of addressing in which the address of an instruction indicates the location of the value with which the instruction is to work.

Mnemonic Representation

Mnemonic representation is an abbreviated form for displaying the names of addresses and programming instructions in the program (for example, “I” stands for “input”). STEP 7 supports the international representation (based on the English language), and the SIMATIC representation (based on the German abbreviations of the instruction set and the SIMATIC addressing conventions).

N Nesting Stack

The nesting stack is a storage byte used by the nesting instructions A(, O(, X(, AN(, ON(, XN(. A total of eight bit logic instructions can be stacked.

Network

Networks subdivide LAD and FBD blocks into complete current paths and Statement List (STL) blocks into clear units.

O OR Bit

Glossary-6

The OR bit is needed if you perform a logical AND before OR operation. The OR bit shows these instructions that a previously executed AND function has supplied the value 1, thus forestalling the result of the logical OR operation. Any other bit-processing command resets the OR bit (see Section 5.4).

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary

Overflow Bit

The status bit OV stands for overflow. An overflow can occur, for example, after a math operation.

P Pointer

You can use a pointer to identify the address of a variable. A pointer contains an identifier instead of a value. If you allocate an actual parameter type, you provide the memory address. With STEP 7 you can either enter the pointer in pointer format or simply as an identifier (for example, M 50.0). In the following example, the pointer format is shown with which data from M 50.0 is accessed: P#M50.0

Project

A project is a folder for all objects in an automation task, irrespective of the number of stations, modules, and how they are connected in networks.

R Reference Data

Reference data are used to check your S7 program and include the cross-reference list, the assignment lists, the program structure, the list of unused addresses, and the list of addresses without symbols.

Register Indirect Addressing

A type of addressing in which the address of an instruction indicates indirectly via an address register and an offset the memory location of the value with which the instruction is to work.

Result of Logic Operation (RLO)

The result of logic operation (RLO) is the result of the logic string which is used to process other binary signals. The execution of certain instructions depends entirely on their preceding RLO.

S S7 Program

A folder for blocks, source files, and charts for S7 programmable controllers. The S7 program also includes the symbol table.

Shared Data Block (DB)

A shared data block is a DB whose address is loaded in the DB address register when it is opened. It provides storage and data for all logic blocks (FCs, FBs, or OBs) that are being executed.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary-7

Glossary

In contrast, an instance DB is designed to be used as specific storage and data for the FB with which it has been associated.

SIMATIC Manager

The SIMATIC Manager is the graphical user interface for SIMATIC users under Windows 95.

Source File

A source file (text file) is part of a program created either with a graphic or a text-oriented editor and is compiled into an executable S7 user program or the machine code for M7. An S7 source file is stored in the “Sources” folder under the “S7 program” folder.

Statement

A statement is the smallest independent part of a user program created in a textual language. The statement represents a command for the processor.

Statement List (STL)

Statement List (STL) is a textual representation of the STEP 7 programming language, similar to machine code. STL is the assembler language of STEP 5 and STEP 7. If you program in STL, the individual statements represent the actual steps in which the CPU executes the program.

Station

A station is a device which can be connected to one or more subnets; for example, the programmable controller, programming device, and operator station.

Status Bit

The status bit stores the value of a bit that is referenced. The status of a bit instruction that has read access to the memory (A, AN, O, ON, X, XN) is always the same as the value of the bit that this instruction checks (the bit on which it performs its logic operation). The status of a bit instruction that has write access to the memory (S, R, =) is the same as the value of the bit to which the instruction writes or, if no writing takes place, the same as the value of the bit that the instruction references. The status bit has no significance for bit instructions that do not access the memory. Such instructions set the status bit to 1 (STA=1). The status bit is not checked by an instruction. It is interpreted during program test (program status) only.

Status Word

The status word is part of the register of the CPU. It contains status information and error information which is displayed when specific STEP 7 commands are executed. The status bits can be read and written on by the user, the error bits can only be read.

STL Source File

A source file programmed in Statement List; corresponds to a source or text file.

Glossary-8

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary

Stored Overflow Bit

The status bit OS stands for “stored overflow bit of the status word”. An overflow can take place, for example, after a math operation.

Symbol

A symbol is a name which can be defined by the user subject to syntax guidelines. After it has been declared (for example, as a variable, data type, jump label, block etc) the symbol can be used for programming and for operator interface functions. Example: Address: I 5.0, data type: BOOL, Symbol: momentary contact switch / emergency stop.

Symbol Table

A table in which the symbols of addresses for shared data and blocks are allocated. Examples: Emergency Stop (symbol) -I 1.7 (address) or closed-loop control (symbol) - SFB24 (block).

Symbolic Addressing

In symbolic addressing, the address being processed is designated with a symbol (as opposed to an absolute address).

System Function (SFC)

A system function is a function (without a memory) that is integrated in the S7 operating system and can, if necessary, be called from the STEP 7 user program like a function (FC).

System Function Block (SFB)

A system function block (SFB) is a function (with a memory) that is integrated in the S7 operating system and can, if necessary, be called from the STEP 7 user program like a function block (FB).

U User Data Types (UDTs)

User data types are special data structures which you can create yourself and use in the entire user program after they have been defined. They can be used like elementary or complex data types in the variable declaration of logic blocks (FCs, FBs, OBs) or as a template for creating data blocks with the same data structure.

User Program

The user program contains all the statements and declarations and all the data for signal processing which can be used to control a device or a process. It is part of a programmable module (CPU, FM) and can be structured with smaller units (blocks).

User Program Structure

The user program structure describes the call hierarchy of the blocks within an S7 program and provides an overview of the blocks used and their dependency.

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Glossary-9

Glossary

V Variable Declaration

The variable declaration includes a symbolic name, a data type and, optionally, an initial value, an address and a comment.

Variable Declaration Table

The variable declaration table is used for declaring the local data of a logic block, when programming takes place in the Incremental Editor.

Variable Table (VAT)

The variable table is used to collect together the variables that you want to monitor and modify and set their relevant formats.

Glossary-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index Symbols )MCR. See Restore RLO, End MCR instruction +. See Instructions, integer math, adding an integer to accumulator 1 +I. See Four-function math, Adding two 16-bit integers; Instructions, integer math, adding two 16-bit integers +R. See Floating-point math, Adding two floating-point numbers =. See Assign (=) instruction

A ABS. See Absolute value, forming the absolute value of a real (floating–point ) number Absolute addressing, practical application, B-4 Absolute value definition of, 10-6 forming the absolute value of a real (floating-point) number, 10-6 Accumulator 1 to Accumulator 2 (PUSH), 4-2 Accumulator 2 to Accumulator 1 (POP), 4-2 Accumulator operations and address register instructions, 4-2–4-6 Accumulator 1 to Accumulator 2 (PUSH), 4-2 Accumulator 2 to Accumulator 1 (POP), 4-2 Decrement Accumulator 1 (DEC), 4-6 Decrement Accumulator 1 (DEC), 4-6 Increment Accumulator 1 (INC), 4-6 Increment Accumulator 1 (INC), 4-6 Toggle ACCU 1 with ACCU 2, 4-2

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Accumulators adding a constant to an address register, 4-7 adding an integer to accumulator 1, 9-6 description of, 2-10 functions Accumulator 2 to Accumulator 1 (POP), 4-2 Decrement Accumulator 1 (DEC), 4-6 Increment Accumulator 1 (INC), 4-6 handling the contents of, 4-2–4-6 information interchange using Load and Transfer instructions, 8-2 loading the status word into, 8-6 operation of, 2-10 with comparison instructions, 11-2 with floating-point math instructions, 10-2–10-3 with integer math instructions, 9-2–9-3 with Load and Transfer instructions, 8-2 with word logic instructions, 13-2, 13-3, 13-6 operations Accumulator 1 to Accumulator 2 (PUSH), 4-2 Decrement Accumulator 1 (DEC), 4-6 Increment Accumulator 1 (INC), 4-6 reversing the order of bytes within accumulator 1 Change Byte Sequence in Accumulator 1, 16 bits (CAW) instruction, 12-13 Change Byte Sequence in Accumulator 1, 32 bits (CAD) instruction, 12-13 time value in, 6-4 Toggle ACCU 1 with ACCU 2, 4-2 Toggle the contents of, 4-2 transferring the contents of to the status word, 8-6

Index-1

Index

ACOS. See Secant Activate MCR Area (MCRA) instruction, 17-11–17-12 Actual parameter, 17-2, 17-3 Actual parameters, assignment, 17-8 AD. See And Double Word instruction Address assigning addresses to a Call (CALL) instruction, 17-3 bits of the status word as, 5-13 constants as, 13-2 description of, 2-2 label for a jump instruction, 16-2 label for a loop instruction, 16-2 of instructions Assign (=), 5-25 Conditional Call (CC), 17-7 counter, 7-10 Edge Negative (FN), 5-19 Edge Positive (FP), 5-19 Load (L) and Transfer (T), 8-3–8-5 Open a Data Block (OPN), 15-2 Reset (R), 5-23 Set (S), 5-23 Timer, 6-17 Unconditional Call (UC), 17-7 symbolic, 17-3 types address identifier and location, 2-5–2-6 constants, 2-3, 13-2 data block, 2-4 function (FC), 2-5 function block (FB), 2-5 location in status word, 2-3 symbolic, 2-4 system function (SFC), 2-5 system function block (SFB), 2-5 Address register, adding a real number to an address register, 4-7 Address registers, 3-6 loading and transferring between, 8-11–8-12

Index-2

Addressing absolute, 17-3, B-4 area-crossing register indirect, 3-11–3-14 area-internal register indirect, 3-7–3-9 constants, 2-3 direct, 3-2 immediate, 3-2 memory indirect, 3-3–3-5 pointer format area-crossing register indirect, 3-13–3-14 area-internal register indirect, 3-8 area–internal register indirect, 3-9–3-10 memory indirect, 3-4–3-5 ranges, 2-9 symbolic, 2-4, 17-3, B-3 And (A), using counters as bit operands, 7-2 And (A) instruction, 5-3 And before Or, 5-15–5-16 And Double Word (AD) instruction, 13-7–13-8 And Not (AN), using counters as bit operands, 7-2 And Not (AN) instruction, 5-3 And Word (AW) instruction, 13-4–13-5 combining accumulator and constant, 13-4–13-5 ANY, 17-9 Arc cosine (ACOS), 10-13–10-15 Arc sine (ASIN), 10-13–10-14 Arc tangent (ATAN), 10-13 Area-crossing register indirect addressing, 3-11–3-15 Area-internal register indirect addressing, 3-7–3-9 Areas of memory address ranges, 2-9 bit memory, 2-8 counter, 2-8 data block, 2-8 I/O (external I/O), 2-8 local data, 2-8 peripheral I/O. See Areas of memory, I/O (external I/O) process image input, 2-8 process image output, 2-8 timer, 2-8 ASIN. See Cosecant Assign (=) instruction, 5-20, 5-24–5-25 Assigning addresses to a Call (CALL) instruction, 17-3 ATAN. See Cotangent AW. See And Word instruction

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

B BCD to Double Integer (BTD) conversion instruction, 12-4 BCD to Integer (BTI) conversion instruction, 12-3–12-4 BCDF. See Errors, binary coded decimal conversion BEC. See Blocks, ending: Block End Conditional instruction Beginning a logic string, 2-12–2-13 BEU. See Blocks, ending: Block End Unconditional instruction Binary coded decimal (BCD) format loading a count in, 8-10 loading a time in, 8-9 Binary coded decimal (BCD) numbers converting, 12-2–12-9 structure of a BCD number converted from a 32-bit integer, 12-6 structure of a BCD number to be converted from integer, 12-5 structure of a BCD number to be converted to integer, 12-3 structure of a32-bit BCD number to be converted to double integer, 12-4 Binary result (BR), bit of status word, 2-16 Bit logic instructions, And (A), using counters as Boolean operands, 7-2 Bit logic Boolean, 5-2–5-12 practical applications, B-3–B-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Bit logic instructions, 5-2–5-5 And Not (AN), using counters as Boolean operands, 7-2 Assign (=), 5-20, 5-24–5-25 Clear RLO (CLR), 5-26–5-27 Edge Negative (FN), 5-16–5-19 Edge Positive (FP), 5-16–5-19 Exclusive Or (X), using counters as Boolean operands, 7-2 Exclusive Or Not (XN), using counters as Boolean operands, 7-2 Negate RLO (NOT), 5-26 Or (O), using counters as Boolean operands, 7-2 Or Not (ON), using counters as Boolean operands, 7-2 practical applications, B-3–B-6 Reset (R), 5-20, 5-21–5-23, 7-8–7-9 counter, 7-4 timer, 6-6 Save RLO in BR Register (SAVE), 5-26 Set (S), 5-20, 5-21–5-23 counter, 7-3, 7-8–7-9 Set RLO (SET), 5-26, 5-27 using counters as bit operands, 7-2 Bit memory area of memory, 2-8 address ranges, 2-9 Blocks, ending Block End Conditional (BEC) instruction, 17-16 Block End Unconditional (BEU) instruction, 17-16 Boolean bit logic, 5-2–5-12 And (A) instruction, 5-3 And Not (AN) instruction, 5-3 checking condition codes (CC 1 and CC 0), 2-14–2-15 checking for overflow, 5-12–5-13 nesting expressions, 5-14–5-15 output of logic string, 5-20 BR. See Binary result BTD. See BCD to Double Integer conversion instruction BTI. See BCD to Integer conversion instruction

Index-3

Index

C CAD. See Change Byte Sequence in Accumulator 1 conversion instruction, 32 bits CALL. See Call instruction Call instruction, 17-3–17-5 Calling a function that delivers a return value, 17-6 Calling a program segment multiple times, 16-8 CAW. See Change Byte Sequence in Accumulator 1 conversion instruction, 16 bits CC. See Conditional Call instruction CC 1 and CC 0. See Condition codes CD. See Count Down instruction CDB. See Exchange Shared DB and Instance DB instruction Change Byte Sequence in Accumulator 1 conversion instruction 16 bits (CAW), 12-13 32 bits (CAD), 12-13 Checking condition codes (CC 1 and CC 0), 2-14–2-15 Clearing RLO (CRL) instruction, 5-26–5-27 the result of logic operation, 5-26–5-27 CLR. See Clear RLO instruction Comparing two integers, 11-3–11-5 two real numbers, 11-5–11-6 Comparison instructions, 11-2–11-3 Compare Double Integer, 11-3–11-5 Compare Integer, 11-3–11-5 Compare Real Number, 11-5 criteria for comparisons, 11-2 operation of accumulators, 11-2 practical applications, B-10–B-11 Complements, forming, 12-14

Index-4

Condition codes (CC 1 and CC 0) as affected by Compare instructions, 11-4, 11-5 as affected by floating-point math instructions, 10-4 as affected by integer math instructions, 9-4 as affected by the shift and rotate instructions, 14-2 as affected by word logic instructions, 13-2 bits of status word, 2-14–2-15 instructions that evaluate CC 1 and CC 0, 11-6 relationship to conditional jump instructions, 16-6 Conditional Call (CC) instruction, 17-7 Conditional jump instructions Jump If BR = 0 (JNBI), 16-5 Jump If BR = 1 (JBI), 16-5 Jump If Minus (JM), 16-6 Jump If Minus or Zero (JMZ), 16-6 Jump If Not Zero (JN), 16-6 Jump If OS = 1 (JOS), 16-5 Jump If OV = 1 (JO), 16-5 Jump If Plus (JP), 16-6 Jump If Plus or Zero (JPZ), 16-6, 16-7 Jump If RLO = 0 (JCN), 16-4 Jump If RLO = 0 with BR (JNB), 16-4 Jump If RLO = 1 (JC), 16-4 Jump If RLO = 1 with BR (JCB), 16-4 Jump If Unordered (JUO), 16-6 Jump If Zero (JZ), 16-6 relationship of condition codes CC 1 and CC 0, 16-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

Constants adding an integer constant to accumulator 1, 9-6 as addresses of word logic instructions, 13-2, 13-4–13-7 Decrement Accumulator 1 by an 8-bit constant, 4-6 Decrementing Accumulator 1 by an 8-bit constant, 4-6 Incrementing Accumulator 1 by an 8-bit constant, 4-6 used as address, 2-3 Conversion instructions BCD to Double Integer (BTD), 12-4 BCD to Integer (BTI), 12-3–12-4 Change Byte Sequence in Accumulator 1 16 bits (CAW), 12-13 32 bits (CAD), 12-13 Double Integer to BCD (DTB), 12-6 Double Integer to Real (DTR), 12-7 Integer to BCD (ITB), 12-5 Integer to Double Integer (ITD), 12-6 Negate Real Number (NEGR), 12-14–12-15 Ones Complement Double Integer (INVD), 12-14 Ones Complement Integer (INVI), 12-14 overview of number conversion and rounding, 12-12 Round (RND), 12-9 Round to Lower Double Integer (RND–), 12-11 Round to Upper Double Integer (RND+), 12-10 Truncate (TRUNC), 12-12 Twos Complement Double Integer (NEGD), 12-14 Twos Complement Integer (NEGI), 12-14–12-15 Converting 32-bit floating-point numbers to 32-bit integers, 12-8–12-12 binary coded decimal numbers and integers, 12-2–12-9 numbers, 12-12 COS. See Cosine Cosine (COS), 10-13 Count Down (CD) instruction, 7-5 Count Up (CU) instruction, 7-5 Count value, format, 7-6–7-7

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Counters area of memory, 2-8 address ranges, 2-9 components, 7-2 count instructions, bit logic instructions, 7-2 count value, format, 7-6–7-7 definition of, 7-2 enabling, 7-4, 7-8–7-9 instructions used with counters, 7-2–7-9 bit logic, 5-22–5-23, 7-2 Count Down (CD), 7-2, 7-5 Count Up (CU), 7-2, 7-5 Enable (FR), 7-2, 7-4 Load Current Counter Value into Accumulator 1 as Binary Coded Decimal (LC), 7-2, 8-10 Load Current Counter Value into Accumulator 1 as Integer, 7-2 practical applications, B-10–B-11 Reset (R), 7-2, 7-4, 7-8–7-9 Set (S), 7-2, 7-3, 7-8–7-9 resetting, 7-2, 7-4, 7-8–7-9 setting, 7-2, 7-3, 7-8–7-9 types Count Down (CD), 7-2, 7-8–7-9 Count Up (CU), 7-2, 7-8–7-9 CPU, registers, 3-6–3-11 nesting stack, 2-10 operation of accumulators, 2-10 pointers, 3-6 status word, 2-12–2-16 time value in accumulator 1, 6-4 CU. See Count Up instruction

Index-5

Index

D Data block (DB) area of memory, 2-8 address ranges, 2-9 instance, 17-3 lengths and numbers, loading, 15-3–15-4 loading the length of a shared data block into accumulator 1 (L DBLG), 8-12, 15-3 loading the length of an instance data block into accumulator 1 (L DILG), 8-12, 15-3 loading the number of a shared data block into accumulator 1 (L DBNO), 8-12, 15-3–15-4 loading the number of an instance data block into accumulator 1 (L DINO), 8-12, 15-3 registers, exchanging, 15-2 Data block (DB) instructions Exchange Shared DB and Instance DB (CDB), 15-2 Load Length of Instance Data Block in Accumulator 1 (DILG), 15-3 Load Length of Shared Data Block in Accumulator 1 (DBLG), 15-3 Load Number of Instance Data Block in Accumulator 1 (DINO), 15-3 Load Number of Shared Data Block in Accumulator 1 (DBNO), 15-3–15-4 Open a Data Block (OPN), 15-2 Data types ANY, 17-9 for actual and formal parameters, 17-3 DBLG. See Load Length of Shared DB in Accumulator 1 instruction DBNO. See Load Number of Shared DB in Accumulator 1 instruction Deactivate MCR Area (MCRD) instruction, 17-11–17-12 DEC. See Decrement Accumulator 1 Decrement Accumulator 1 (DEC), 4-6 DILG. See Load Length of Instance DB in Accumulator 1 instruction DINO. See Load Number of Instance DB in Accumulator 1 instruction Direct addressing, 3-2 Double Integer to BCD (DTB) conversion instruction, 12-6 Double Integer to Real (DTR) conversion instruction, 12-7 Double integers, comparing two, 11-3–11-5 DTB. See Double Integer to BCD conversion instruction

Index-6

DTR. See Double Integer to Real conversion instruction

E Edge Negative (FN) instruction, 5-16–5-19 Edge Positive (FP) instruction, 5-16–5-19 Enable (FR) instruction counters, 7-4, 7-8–7-9 timers, 6-6 Enable output (ENO). See Binary result Ending blocks Block End Conditional (BEC) instruction, 17-16 Block End Unconditional (BEU) instruction, 17-16 Errors, binary coded decimal conversion (BCDF), 12-3, 12-4 Examples, practical applications of instructions, B-2–B-14 Exchange Shared DB and Instance DB (CDB) instruction, 15-2 Exchange the contents of accumulators, 4-2 Exclusive Or (X), using counters as Boolean operands, 7-2 Exclusive Or Not (XN), using counters as Boolean operands, 7-2 Exclusive Or Word (XOW) instruction, 13-3, 13-4–13-5 combining accumulator and constant, 13-4–13-5 EXP. See Exponential value to base E Exponential value to base E, EXP, 10-12 Extended Pulse Timer (SE), 6-5, 6-9–6-10

F FBs. See Function blocks FCs. See Functions First check (FC) bit of status word, 2-12–2-13 result of, 2-12

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

Floating-point math Adding two floating-point numbers (+R), 10-3, 10-4 instructions forming the absolute value of a real number (ABS), 10-6 overview of four-function math, 10-2 relationship to accumulators, 10-2–10-3 valid ranges of result, 10-4 Floating-point math, extended operations arc cosine (ACOS), 10-13–10-15 arc tangent (ATAN), 10-13 Floating-point math, extended math operations, arc sine (ASIN), 10-13–10-14 FN. See Edge Negative instruction Formal parameter, 17-2 Formal parameters, 17-3 Format count value, 7-6–7-7 time value, 6-4 Forming complements, 12-14 Four-function math, Adding two 16-bit integers (+I), 9-3 FP. See Edge Positive instruction FR. See Enable instruction Function (FC) as address of an instruction, 2-5 calling FCs with the Call (CALL) instruction, 17-3–17-5 calling FCs with the Conditional Call (CC) instruction, 17-7 calling FCs with the Unconditional Call (UC) instruction, 17-7 dependency on Master Control Relay (MCR), 17-11 Function block (FB) as address of an instruction, 2-5 calling FBs with the Call (CALL) instruction, 17-3–17-5 calling FBs with the Conditional Call (CC) instruction, 17-7 calling FBs with the Unconditional Call (UC) instruction, 17-7 dependency on Master Control Relay (MCR), 17-11

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

I I/O (external I/O) area of memory, 2-8 address ranges, 2-9 Image registers. See Process-image Immediate addessing, 3-2 INC. See Increment Accumulator 1 Increment Accumulator 1 (INC), 4-6 Instruction statement addressing constants, 2-3 symbolic, 2-4 structure of, 2-2–2-7 Instructions accumulator operation and address register, 4-2–4-6 alphabetical listing, international names, A-12–A-16 bit logic, practical applications, B-3–B-6 comparison, 11-2–11-8 criteria for comparison, 11-2 operation of accumulators, 11-2 practical applications, B-10–B-11 conversion, overview of number conversion and rounding, 12-12 counter, 7-2–7-13 practical applications, B-10–B-11 dependent on the Master Control Relay (MCR), 17-11 dependent on the Master control Relay (MCR), 17-10 floating-point math overview of four-function math, 10-2 relationship to accumulators, 10-2–10-3 valid ranges of results, 10-4 integer math overview of four-function math instructions, 9-2 practical applications, B-12–B-13 relationship to accumulators, 9-2–9-3 valid ranges of results, 9-4 jump, unconditional, 16-3–16-4 Load (L) and Transfer (T), 8-2–8-12 area-crossing indirect addressing, 8-5

Index-7

Index

byte, word, or double word as address, 8-5 definition of, 8-2 direct addressing, 8-4 immediate addressing, 8-3 indirect addressing, 8-4 information interchange, 8-2 loading and transferring between address registers (LAR and TAR), 8-11–8-12 loading bits of the status word into accumulator 1, 8-6 loading the status word into accumulator 1, 8-6 transferring the contents of accumulator 1 to the status word, 8-6 loading and transferring between address registers (LAR and TAR), 8-11–8-12 logic control, 16-2–16-11 See also Jump instructions Loop (LOOP), 16-8 providing a label as address, 16-8 using efficiently, 16-9 practical applications, B-2–B-14 program control, assigning addresses to a call, 17-3 rotate, 14-6–14-8 shift, 14-2–14-6 signed numbers, 14-4 unsigned numbers, 14-2–14-3 shift and rotate, 14-2–14-6 that evaluate the condition codes (CC 1 and CC 0), 9-4, 10-4 that evaluate the overflow bit (OV) of the status word, 9-4, 10-4 that evaluate the stored overflow bit (OS) of the status word, 9-4, 10-4 timer, 6-2–6-17 practical applications, B-7–B-10 Transfer (T). See Load (L) and Transfer (T) instructions word logic, 13-2–13-8 16-bit, 13-3–13-8 32-bit, 13-6–13-8 accumulator administration, 13-2, 13-3, 13-6 constants as addresses, 13-2 influence on status word bits, 13-2 practical applications, B-14 Instructions that affect the status word, 5-10 Integer math, adding a real to an address register, 4-7

Index-8

Integer math instructions adding an integer constant to accumulator 1, 9-6 adding two 16-bit integers (+I), 9-3 overview of four-function math instructions, 9-2 practical applications, B-12–B-13 relationship to accumulators, 9-2–9-3 valid ranges of results, 9-4 Integer to BCD (ITB) conversion instruction, 12-5 Integer to Double Integer (ITD) conversion instruction, 12-6 Integers adding to accumulator 1, 9-6 comparing two, 11-3–11-5 converting, 12-2–12-9 International names for instructions, alphabetical listing, A-12–A-16 International names of the statement list (STL) instructions, A-12 INVD. See Ones Complement Double Integer conversion instruction Inverting numbers bit by bit, 12-14 INVI. See Ones Complement Integer conversion instruction ITB. See Integer to BCD conversion instruction ITD. See Integer to Double Integer conversion instruction

J JBI. See Jump If BR = 1 instruction JC. See Jump If RLO = 1 instruction JCB. See Jump If RLO = 1 with BR instruction JCN. See Jump If RLO = 0 instruction JL. See Jump to List instruction JM. See Jump If Minus instruction JMZ. See Jump If Minus or Zero instruction JN. See Jump If Not Zero instruction JNB. See Jump If RLO = 0 with BR instruction JNBI. See Jump If BR = 0 instruction JO. See Jump If OV = 1 instruction JOS. See Jump If OS = 1 instruction JP. See Jump If Plus instruction JPZ. See Jump If Plus or Zero instruction JU. See Jump Unconditional instruction Jump If BR = 0 (JNBI) instruction, 16-5 Jump If BR = 1 (JBI) instruction, 16-5 Jump If Minus (JM) instruction, 16-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

Jump If Minus or Zero (JMZ) instruction, 16-6 Jump If Not Zero (JN) instruction, 16-6 Jump If OS = 1 (JOS) instruction, 16-5 Jump If OV = 1 (JO) instruction, 16-5 Jump If Plus (JP) instruction, 16-6 Jump If Plus or Zero (JPZ) instruction, 16-6, 16-7 Jump If RLO = 0 (JCN) instruction, 16-4 Jump If RLO = 0 with BR (JNB) instruction, 16-4 Jump If RLO = 1 (JC) instruction, 16-4 Jump If RLO = 1 with BR (JCB) instruction, 16-4 Jump If Unordered (JUO) instruction, 16-6 Jump If Zero (JZ) instruction, 16-6 Jump instructions, 16-3–16-10 condition based on BR, OV, or OS bit of status word, 16-5 condition based on result in condition code bits (CC 1 and CC 0) of status word, 16-6–16-7 condition based on result of logic operation (RLO), 16-4–16-5 conditional Jump If BR = 0 (JNBI), 16-5 Jump If BR = 1 (JBI), 16-5 Jump If Minus (JM), 16-6 Jump If Minus or Zero (JMZ), 16-6 Jump If Not Zero (JN), 16-6 Jump If OS = 1 (JOS), 16-5 Jump If OV = 1 (JO), 16-5 Jump If Plus (JP), 16-6 Jump If Plus or Zero (JPZ), 16-6, 16-7 Jump If RLO = 0 (JCN), 16-4 Jump If RLO = 0 with BR (JNB), 16-4 Jump If RLO = 1 (JC), 16-4 Jump If RLO = 1 with BR (JCB), 16-4 Jump If Unordered (JUO), 16-6 Jump If Zero (JZ), 16-6 label as address, 16-2 overview of, 16-2 unconditional, 16-3–16-4 Jump to List (JL), 16-3 Jump Unconditional (JU), 16-3 Jump to List (JL) instruction, 16-3 Jump Unconditional (JU) instruction, 16-3 JUO. See Jump If Unordered instruction JZ. See Jump If Zero instruction

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

K Keywords, definition, C-1

L L. See Load and Transfer instructions Label, as address of a jump or loop instruction, 16-2 LAR. See Loading and transferring between address registers LC. See Load Current Value into Accumulator 1 as Binary Coded Decimal LN. See Natural Logarithm Load (L) and Transfer (T) instructions, 8-2–8-12 See also Instructions, Load (L) and Transfer (T) area-crossing indirect addressing, 8-5 byte, word, or double word as address, 8-5 definition of, 8-2 direct addressing, 8-4 immediate addressing, 8-3 indirect addressing, 8-4 information interchange, 8-2 between modules and memory areas, 8-2 by way of the accumulator, 8-2 Load Current Counter Value into Accumulator 1 as Binary Coded Decimal (LC), 8-10 loading and transferring between address registers (LAR and TAR), 8-11–8-12 loading bits of the status word into accumulator 1, 8-6 loading the length of a shared data block into accumulator 1 (L DBLG), 8-12 loading the length of an instance data block into accumulator 1 (L DILG), 8-12 loading the number of a shared data block into accumulator 1 (L DBNO), 8-12 loading the number of an instance data block into accumulator 1 (L DINO), 8-12 loading the status into accumulator 1, 8-6 transferring the contents of accumulator 1 to the status word, 8-6 Load Current Value into Accumulator 1 as Binary Coded Decimal counter, 7-2 timer, 6-2

Index-9

Index

Load Length of Instance DB in Accumulator 1 (DILG) instruction, 15-3 Load Length of Shared DB in Accumulator 1 (DBLG) instruction, 15-3 Load Number of Instance DB in Accumulator 1 (DINO) instruction, 15-3 Load Number of Shared DB in Accumulator 1 (DBNO) instruction, 15-3–15-4 Loading a count value format, 7-6 in binary coded decimal (BCD) format (LC counter word), 8-10 in binary form (L counter word), 8-8 Loading a time value format, 6-3 in binary coded decimal (BCD) format (LC timer word), 8-9 in binary form (L timer word), 8-7 range, 6-5 Loading and transferring between address registers, 8-11–8-12 Loading data block lengths and numbers, 15-3–15-4 Loading the length of a data block into accumulator 1 instance data block (L DILG), 8-12 shared data block (L DBLG), 8-12 Loading the number of a data block into accumulator 1 instance data block (L DINO), 8-12 shared data block (L DBNO), 8-12 Local data, area of memory, 2-8 address ranges, 2-9 Logic control instructions, 16-2–16-11 See also Jump and Loop instructions Logic string beginning of, 2-12–2-13 definition of, 2-12–2-13 output of, 5-20 terminating, 5-20 Loop (LOOP) instruction, 16-8 label as address, 16-2, 16-8 using efficiently, 16-9

Master Control Relay (MCR) instructions, 17-10–17-15 See also Program control instructions nesting, 17-13–17-15 MCR functions, Important notes, 17-15 MCR(. See Save RLO in MCR Stack, Begin MCR instruction MCRA. See Activate MCR Area instruction MCRD. See Deactivate MCR Area instruction Memory areas address ranges, 2-9 bit memory, 2-8 counter, 2-8 data block, 2-8 I/O (external I/O), 2-8 local data, 2-8 process image input, 2-8 process image output, 2-8 timer, 2-8 Memory indirect addressing, 3-3–3-5 Multiplying a number by –1, 12-14

N Natural Logarithm (LN), 10-11 Negate Real Number (NEGR) conversion instruction, 12-14–12-15 Negate RLO (NOT) instruction, 5-26 Negating numbers, 12-14 Negating the result of logic operation, 5-26 Negative edge transitions, 5-16–5-19 NEGD. See Twos Complement Double Integer conversion instruction NEGI. See Twos Complement Integer conversion instruction NEGR. See Negate Real Number conversion instruction Nesting expressions, 5-14–5-17 And before Or, 5-15–5-16 Nesting stack, 2-10, 5-14 Normally closed contact, 5-7 Normally open contact, 5-6 NOT. See Negate RLO instruction

M Master Control Relay (MCR) dependency on, 17-10, 17-11 effect on Set (S) and Reset (R) instructions, 5-21–5-22, 17-10 implementation of, 17-13 Important notes, 17-15

Index-10

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

O Off-Delay Timer (SF), 6-5, 6-15–6-16 On-Delay Timer (SD), 6-5, 6-11–6-12 Ones Complement Double Integer (INVD) conversion instruction, 12-14 Ones Complement Integer (INVI) conversion instruction, 12-14 Open a Data Block (OPN) instruction, 15-2 Operand. See Address OPN. See Open a Data Block instruction OR, bit of status word, 2-14 Or (O), using counters as bit operands, 7-2 Or branch, nesting expressions, 5-14–5-17 Or Not (ON), using counters as bit operands, 7-2 Or Word (OW) instruction, 13-3, 13-4–13-5 combining accumulator and constant, 13-4–13-5 Order of processing And with Or instructions, 5-15–5-16 OS. See Stored overflow Output of a logic string, 5-20 OV. See Overflow Overflow (OV) as affected by comparing two real numbers, 11-5 as affected by floating-point math instructions, 10-4 as affected by integer math instructions, 9-4 as affected by the shift and rotate instructions, 14-2 as affected by word logic instructions, 13-2 bit of status word, 2-14

P Parallel branch, nesting expressions, 5-14–5-17 Parameters actual, 17-3 formal, 17-3 Pointer format area-crossing register indirect addressing, 3-13–3-14 area–internal register indirect addressing, 3-9 memory indirect addressing, 3-4–3-5 POP. See Accumulator 2 to Accumulator 1 Positive edge transitions, 5-16–5-19

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Process image input area of memory, 2-8 Process image output area of memory, 2-8 Process-image input area of memory, address ranges, 2-9 Process-image output area of memory, address ranges, 2-9 Processing order for And with Or instructions, 5-15–5-16 Program control instructions Activate MCR Area, 17-11–17-12 assigning addresses to a Call (CALL) instruction, 17-3 Block End Conditional (BEC), 17-16 Block End Unconditional (BEU), 17-16 Call (CALL), 17-3–17-5 Conditional Call (CC), 17-7 Deactivate MCR Area, 17-11–17-12 Master Control Relay (MCR) functions, 17-10–17-15 Restore RLO, End MCR: )MCR, 17-11–17-12, 17-13–17-14 Save RLO in MCR Stack, Begin MCR: MCR(, 17-11–17-12, 17-13–17-14 Unconditional Call (UC), 17-7 Programming, practical applications, B-2–B-14 Pulse Timer (SP), 6-5–6-6, 6-7–6-8 PUSH. See Accumulator 1 to Accumulator 2

R R. See Reset instruction Real number comparing two real numbers, 11-5 forming the absolute value, 10-6 Registers address, 3-6 CPU, 3-6–3-11 Exchange Shared DB and Instance DB (CDB) instruction, 15-2 exchanging data block registers, 15-2 image. See Process-image Reset (R) instruction, 5-20, 5-21–5-23 counters, 7-4, 7-8–7-9 timers, 6-6 Resetting a counter, 7-4 a timer, 6-6

Index-11

Index

Restore RLO, End MCR instruction: )MCR, 17-11–17-12, 17-13–17-14 Result of logic operation (RLO) bit of status word, 2-13 clearing, 5-26–5-27 instructions that do not affect the RLO, 4-6 negating, 5-26 relationship to Block End instructions, 17-16 saving, 5-26 setting, 5-26, 5-27 stored in nesting stack, 5-14 transitions of, 5-16–5-19 with Assign (=) instruction, 5-24–5-25 Retentive On-Delay Timer (SS), 6-5, 6-13–6-14 Return value, calling a function that delivers a return value, 17-6 Reversing the order of bytes within accumulator 1, 12-13 RLD. See Rotate instructions, Rotate Left Double Word RLDA. See Rotate instructions, Rotate Accumulator 1 Left via CC 1 RLO. See Result of Logic Operation RND. See Round conversion instruction RND+. See Round to Upper Double Integer conversion instruction RND–. See Round to Lower Double Integer conversion instruction Rotate instructions, 14-6–14-8 Rotate Accumulator 1 Left via CC 1 (RLDA), 14-8 Rotate Accumulator 1 Right via CC 1 (RRDA), 14-8 Rotate Left Double Word (RLD), 14-7–14-8 Rotate Right Double Word (RRD), 14-7 Round (RND) conversion instruction, 12-9 Round to Lower Double Integer (RND–) conversion instruction, 12-11 Round to Upper Double Integer (RND+) conversion instruction, 12-10 Rounding 32-bit floating-point numbers to double integers, 12-8–12-11 numbers, overview, 12-12 real numbers to double integers, 12-8–12-11 RRD. See Rotate instructions, Rotate Right Double Word RRDA. See Rotate instructions, Rotate Accumulator 1 Right via CC 1

Index-12

S S. See Set instruction S5 TIME time base, 6-4–6-5 time value, 6-3 SAVE. See Save RLO in BR Register instruction Save RLO in BR Register (SAVE) instruction, 5-26 Save RLO in MCR Stack, Begin MCR instruction: MCR(, 17-11–17-12, 17-13–17-14 Saving, the result of logic operation, 5-26 SD. See On–Delay Timer SE. See Extended Pulse Timer SET. See Set RLO instruction Set (S) instruction, 5-20, 5-21–5-23 counters, 7-3 Set RLO (SET) instruction, 5-26, 5-27 Setting a counter, 7-3, 7-8–7-9 the result of logic operation, 5-26, 5-27 SF. See Off–Delay Timer SFBs. See System function blocks SFCs. See System functions Shift and rotate instructions, 14-2–14-8 Shift instructions, 14-2–14-6 effect on condition codes CC 1 and CC 0 and on the Overflow bit(OV) of the status word, 14-2 method of operation, 14-2 Shift Left Double Word (SLD, 32 bits), 14-2 Shift Left Word (SLW, 16 bits), 14-2 Shift Right Double Word (SRD, 32 bits), 14-2, 14-3 Shift Right Word (SRW, 16 bits), 14-2 Shift Sign Double Integer (SSD, 32 bits), 14-4 Shift Sign Integer (SSI, 16 bits), 14-4 signed numbers, 14-4 unsigned numbers, 14-2–14-3 SIMATIC and International mnemonic abbreviations of the statement list (STL) instructions, A-2, A-7 SIN. See Sine Sine (SIN), 10-13 SLD. See Shift instructions, Shift Left Double Word SLW. See Shift instructions, Shift Left Word

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

Index

SP. See Pulse Timer SQR. See Square SQRT. See Square root Square (SQR), 10-9 Square root (SQRT), 10-9 SRD. See Shift instructions, Shift Right Double Word SRW. See Shift instructions, Shift Right Word SS. See Retentive On–Delay Timer SSD. See Shift instructions, Shift Sign Double Integer SSI. See Shift instructions, Shift Sign Integer STA. See Status, bit of status word Starting a logic string, 2-12–2-13 Starting a timer, 6-5 Statement. See Instruction statement Statement list (STL), 1-1 definition of, 1-1 Status (STA), bit of status word, 2-13 Status word binary result (BR) bit, 2-16 bits affected by floating-point math instructions, 10-4 bits affected by integer math instructions, 9-4 bits affected by the shift and rotate instructions, 14-2 condition code bits (CC 1 and CC 0), overflow bit (OV) as affected by word logic instructions, 13-2 condition code bits CC 1 and CC 0, relationship to conditional jump instructions, 16-6 condition codes (CC 1 and CC 0), 2-14–2-15 condition codes CC 1 and CC 0 after a Compare instruction, 11-4, 11-5 description of, 2-12–2-16 evaluation of 32-bit integer math result, 9-4 first check (FC) bit, 2-12–2-13 indication of valid range for integer math result, 9-4 instructions that affect the status word, 5-10 instructions that evaluate the bits of the status word, 11-6 OR bit, 2-14 overflow (OV) bit, 2-14 overflow bit (OV) after a Compare Real number instruction, 11-5 reading using the Load (L) instruction, 8-6

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

result of logic operation (RLO) bit, 2-13 status (STA) bit, 2-13 stored overflow (OS) bit, 2-14 stored overflow bit (OS) after a Compare Real number instruction, 11-5 transferring the contents of accumulator 1 to it, 8-6 STL instructions, alphabetical listing arranged by International full name, A-12–A-16 arranged by the International mnemonic abbreviations, A-7–A-11 arranged by the SIMATIC mnemonic abbreviations, A-2–A-11 Stored overflow (OS) as affected by floating-point math instructions, 10-4 as affected by integer math instructions, 9-4 bit of status word, 2-14 Stored overflow (OV), as affected by comparing two real numbers, 11-5 Structure of an instruction statement, 2-2–2-7 STW. See Status word Swapping, data block registers, 15-2 Symbolic addresses, 17-3 Symbolic addressing, 2-4, 17-3 practical example, B-3 System function blocks (SFBs), as address of an instruction, 2-5 System functions (SFCs), as address of an instruction, 2-5

T T. See Load and Transfer instructions TAK. See Toggle Accumulator 1 with Accumulator 2 TAN. See Tangent Tangent (TAN), 10-13 TAR. See Loading and transferring between address registers Terminating a logic string, 5-20 Terminating the scanning of a block, 17-16 Time base for S5 TIME, 6-4–6-5 Time resolution. See Time base for S5 TIME

Index-13

Index

Time value format in accumulator 1, 6-4 range, 6-3–6-4 syntax, 6-3 Timers area of memory, 2-8 address ranges, 2-9 components, 6-3–6-4 definition of, 6-2 enabling, 6-6 instructions used with, 6-2–6-17 instructions used with timers bit logic, 5-22–5-23 Enable (FR), 6-6 Extended Pulse Timer (SE), 6-5, 6-9–6-10 Off-Delay Timer (SF), 6-5, 6-15–6-16 On-Delay Timer (SD), 6-5, 6-11–6-12 practical applications, B-7–B-10 Pulse Timer (SP), 6-5–6-6, 6-7–6-8 Reset (R), 6-6 Retentive On-Delay Timer (SS), 6-5, 6-13–6-14 location in memory, 6-3 number supported, 6-3 resetting, 6-6 resolution. See Time base for S5 TIME starting, 6-5 time base for S5 TIME, 6-4–6-5 time value, 6-3 range, 6-3–6-4 syntax, 6-3 types, 6-2 Extended Pulse (SE), 6-2, 6-5, 6-9–6-10 Off-Delay (SF), 6-2, 6-5, 6-15–6-16 On-Delay (SD), 6-2, 6-5, 6-11–6-12 overview, 6-18 Pulse (SP), 6-2, 6-5–6-6, 6-7–6-8 Retentive On-Delay (SS), 6-2, 6-5, 6-13–6-14 Toggle Accumulator 1 with Accumulator 2. See TAK

Index-14

Toggle the contents of Accumulator 1 with Accumulator 2, 4-2 Transfer (T) instruction. See Load (L) and Transfer (T) instructions Transferring the contents of accumulator 1 to the status word, 8-6 Transitional contacts, 5-16–5-19 TRUNC. See Truncate conversion instruction Truncate (TRUNC) conversion instruction, 12-12 Twos Complement Double Integer (NEGD) conversion instruction, 12-14 Twos Complement Integer (NEGI) conversion instruction, 12-14–12-15

U UC. See Unconditional Call instruction Unconditional Call (UC) instruction, 17-7 Unconditional jump instructions Jump to List (JL), 16-3 Jump Unconditional (JU), 16-3

W Word logic instructions, 13-2–13-8 16-bit, 13-3–13-8 32-bit, 13-6–13-8 accumulator administration, 13-2, 13-3, 13-6 And Double Word (AD), 13-7–13-8 And Word (AW), 13-4, 13-5 Exclusive Or Word (XOW), 13-3 Or Word (OW), 13-3, 13-4 practical applications, B-14

X X. See Exclusive Or instruction XN. See Exclusive Or Not instruction

Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

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Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01

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Statement List (STL) for S7-300/S7-400 C79000-G7076-C565-01