256rax

BASIC SWITCHING SYSTEMS C-DOT 256P RAX

C-DOT 256P RAX

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C-DOT 256P RAX INDEX Ch

TOPIC

PAGE

1

Introduction

1

2

System Architecture

3–7

3

Hardware Architecture

8 - 38

4

Subscriber Features

39 - 49

5

Exchange Operations

50 - 64

6

Startup Procedure

65 - 68

7

Fault Handling

69 -77

8

256P RAX Installation

78 – 90

App. A Specification Summary

91 – 94

App. B Equipment Summary

95

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CHAPTER 1 INTRODUCTION 1.1. OVERVIEW The C-DOT 256 Rural Automatic Exchange (RAX) is a digital Stored Program Controlled (SPC) switching system with a capacity of 256 terminations. These terminations include subscriber lines, trunks to other exchanges and tones. 256 RAX can act as a terminal exchange, Integrated Local cum Transit (ILT) exchange or purely transit exchange. This could be placed in a secondary switching area as a tertiary centre - providing connectivity amongst a number of RAXs, TAX and manual trunk positions in addition to local subscribers. The system employs a completely non-blocking 4-wire PCM switching network, which forms the basis of high capacity, total system availability and high traffic handling capability. The system has been designed to suit the distinctive needs of developing countries like India. It incorporates the following design features to meet the rigorous demands of such an environment. ™ Low power components are used to reduce power consumption and heat generation. ™ Duplication of all critical electronics circuitry ensures that a single fault does not affect more than 8 terminals. ™ High system reliability is ensured by automatic on-line diagnostics for fault isolation and recovery. ™ Ease of installation ™ Flexible system dimensioning ™ An easy to use, exhaustive set of subscriber, maintenance and system features.

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Chapter 2 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Chapter 7 Chapter 8 AppendixA AppendixB

Describes the System Architecture Gives the Functional description of various hardware modules used in the system Describes the Subscriber Features Describe Operation and Maintenance (O&M) aspects of the system Briefly explains the Startup Procedure Explains the Fault Handling in 256P RAX Explains the RAX Installation details Specification Summary Equipment Summary – Printed Circuit Boards

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CHAPTER 2. SYSTEM ARCHITECTURE 2.1. OVERVIEW The C-DOT 256P RAX has been designed by reconfiguring the basic building block used in higher capacity systems of the C-DOT DSS family. The system is highly modular, and flexible to the changing technology. The software is structured and clear interfaces exist between hardware and software. The redundancy of critical circuitry and exhaustive set of diagnostic schemes ensure high system reliability.

2.2. SYSTEM HARDWARE BLOCKS (REFER FIG. 2.1 & 2.2) All subscriber lines and trunks are interfaced to the system through the Terminal Interface cards. Each terminal interface card caters to 8 terminations. Four such cards form a Terminal Group. There are 32 such terminal interface cards; sixteen in each frame (C-DOT 256P RAX has a two frame implementation. The top frame is called ‘Slave Frame’ and bottom frame is called ‘Master Frame’).

2.2.1. Terminal Group (TG) Analog information from the terminations is first changed to digital PCM form at a bit rate of 64 Kbps. Thirty two such PCM (Pulse Code Modulation) channels from four Terminal Interface cards are time division multiplexed to generate one 32 channel, 2.048 Mbps PCM link. However, inputs from 30 channel digital trunks is given directly on the 32 channel 2.048 Mbps link. Thus from 32 terminal interface cards, eight such PCM links are obtained. Four of these links are terminated on RSC (RAX Switch Controller card) of master frame and the other four are terminated on RSC of slave frame.

2.2.2. RAX Switch Controller Card (RSC) RSC has 256x256 non-blocking 4-wire PCM switch. Four PCM 32-channel 2.048 Mb/s links from terminal groups of self-frame and four PCM 32-channel 2.048 C-DOT 256P RAX CHAPTER 1 3

Mb/s switched links from RSC of other frame are terminated on each RSC. Switching is done by RSC under control of RAP (RAX Administrative Processor). Four PCM 32 channel 2.048 Mb/s links carry the switched information of the terminations. There are two RSC cards (copy 0 & copy 1) in each frame. RSC in Master frame communicates with self-RAP, its duplicated RSC and slave RSC of self-plane via ACIA links. It also has provision for three HDLC links to communicate with RAX Terminal Test Card (RTC) and two RAX Multi-frequency cards (RMF0 and RMF1). In the slave frame, 2 HDLC links are used to communicate with RWC cards. It monitors power supply cards for faults continuously and interacts with Signalling Processor Card (SPC) using standard 65C02 data bus and control signals.

2.2.3. Signalling Processor Card (SPC) / Integrated Signalling Processor Card (ISP) Signalling information related to terminations such as dialled digits, ring trip, trunk seizure etc., are separated at the Terminal Interface cards and carried to the Signalling Processor (SP/ISP) on a time-multiplexed link. The SP/ISP passes on this information to the RSC. Similarly the SP/ISP is used for outpulsing digits, detecting reversal etc.

2.2.4. RAX Administrative Processor (RAP) Card RAP is a microprocessor based controller card, which handles the call processing functions. RAP sends the termination related information to the RSC over the ACIA link.

2.2.5. Maintenance Panel Maintenance Panel is connected to the RAP via a RS-232C link for system operations and maintenance functions.

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2.2.6. Power and Ringing A DC-DC converter generates the various voltages required for the system operation and also provides ringing for the subscriber loops.

FIG: 2.1 SYSTEM OVERVIEW 256P RAX SLAVE FRAME

T

MASTER FRAME

PRINTE R

T 230V+10% 50Hz Single

C-DOT 256P RAX

MAINTENANC E PANEL

-48V DC POWER PLANT

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FIG: 2.2

C-DOT 256P RAX

256P RAX H/W ARCHITECTURE (SINGLE PLANE)

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6

TG 5

TG 6

COPY 0

P

COPY 1

S

R

R

S

TG 7

TG 8

S

T

T

T

T

T

T

T

T

P

S

S

P

T

T

T

T

T

T

T

T

S

U

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

C

U

0

0

1

1

11

12

15

16

0 1

2

3

4

5

6

7

8

9

C

S

T

T

T

T

/

U

C

C

C

C

C

0

N

13

14

T

T P

10

R T C

R A T 0

F

TG 1

/ R M F

FIG: 2.3

1 17

18

19

20

T S

R

R

R

R

S

P

S

A

A

S

P

C

C

P

P

C

C

0

0

0

1

1

1

0

TG 2

C-DOT 256P RAX

C

C / R M F

R

COPY 1

21

22

23

24

R

R

D

D

P

T

T

S

T

T

C

S

T

C

C

/

C

C

/

U

T

T

1

C

C

1

TG 3

TG 4

256P RAX CARD FRAME

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A

1

COPY 0

S L A V E

P

7

26

M A S T E R

CHAPTER 3 HARDWARE ARCHITECTURE 3.1. OVERVIEW The integrated circuits used in the C-DOT 256P RAX hardware have low power dissipation and high operational reliability. The components used are based on Metal-Oxide Semiconductor (MOS), Complementary MOS (CMOS), Low-Power Schottky Transistor-Transistor Logic (LSTTL), and bipolar technologies. All the system circuitry has been packaged into twenty card types. On the broad level, these could be divided into following categories: • Terminal Interfaces • Subscriber Line Card (Ordinary LCC/CCM) • 4 wire E&M Trunk Card (EMF) • Two way Trunk Card (TWT) • 30-Channel Digital Trunk Unit • RAX Digital Trunk CAS Card (RDC) • RAX Digital Trunk Sync Card (RDS) • RAX WiLL Controller (RWC) card (support two 30-channel DTs) • RAX 10-Channel Digital Trunk Card (RDT) • Controller Cards • RAX Administrative Processor Card (RAP) • RAX Switch Controller Card (RSC) • Signalling Processor Card (SPC)/ Integrated Signalling Processor Card (ISP) • Service Cards • RAX Multi-frequency Card (RMF) • RAX Announcement Cum Tones Card (RAT) • Conference Card (CNF) C-DOT 256P RAX

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• RAX Terminal Test Card (RTC) • Maintenance Panel • Controller Card • Keyboard Card • Display Card • Power Supply Unit (PSU) • RAX Network Synchronization (RNS) Card 3.2. TERMINAL INTERFACES The C-DOT 256 RAX has broadly two types of Terminal Interfaces: • Analog Terminal Interfaces -

Subscriber Line Card (LCC/CCM)

-

4 Wire E&M Card (EMF)

-

Two way Trunk Card (2 Wire)

• Digital Terminal Interfaces -

30 Channel Digital Trunk Unit (RDS/RDC)

-

RAX 10 Channel Digital Trunk Card (RDT)

-

RAX WLL Controller (RWC)

3.2.1. Analog Terminal Interfaces Each terminal interface card caters to 8 terminations. Four cards make a Terminal Group (TG), which is associated with PCM 32-channel link towards the RSC. Signalling information are multiplexed and placed on 4 wires ABCD signalling Bus toward RSC. 3.2.1.1. Subscriber Line Card (LCC/CCM) (Ref. Fig. 3.1) Line Circuit Card (LCC) is used to interface ordinary subscriber lines. Fig. 3.1 gives the detailed block diagram of this card. The Line Circuit Card performs a set of functions collectively termed as BORSCHT, signifying: C-DOT 256P RAX

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Battery Feed

O-

Overvoltage Protection

R-

Ringing

S-

Supervision

C-

Coding

H-

Hybrid Conversion

T-

Testing

FIG. 3.1 LINE CIRCUITCARD (8CIRCUIT/ CARD)

B-

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Battery Feed • A -48V battery with current limiting facility is provided on each line for signalling purposes and for energizing the microphone. Overvoltage Protection • A hybrid transformer and surge arresters across Tip and Ring provide protection against over voltages. Ringing • Ringing is extended to subscribers under the control of Signalling Processor (SP/ISP), through the contacts of an energized relay. The Ring is tripped when off-hook condition is detected. Supervision • On/Off-hook detection and dialling make/break are encoded and passed on to SP/ISP as the scan information from the subscriber lines. Coding • Coding refers to encoding of analog voice to digital form (8 bit, A-law PCM) through a coder/decoder (CODEC). CODEC outputs of 32 CODECs of each Terminal Group are time division multiplexed to form a PCM 32channel at 2.048 Mbps. Hybrid Conversion • 2-wire to 4-wire conversion is done before coding for full duplex (voice) operation. Testing • Metallic access is provided on subscriber lines for routine tests (Tests Access Relays). Coin Collection Box (CCB) is an ordinary LCC with an additional reversal relay per subscriber to extend reversal on called party answer. This card is basically used to cater to special requirements of PCOs and PABXs. However, this card can also be used as line circuit card (LCC). Coin Collection Box with Metering (CCM) card is also same as LCC/CCB card except that it has got extra hardware to generate and feed 16-KHz pulses towards subscriber premise. This card is basically used to interface STD PCOs or special subscribers having home metering requirements. However, in CCM card out of eight ports only last two i.e., C-DOT 256P RAX

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Port no. 7 and 8 are equipped with 16-KHz pulse generator. Therefore, only two subscribers per CCM card may have this provision. Rest of the ports is used for ordinary subscribers or Coin Collection Box type. This card as a whole can be used as LCC. 3.2.1.2. 4-Wire E&M Trunk Card (EMF) (Refer Fig. 3.2) EMF card provides 4-wire E&M trunks to the carrier equipment. One EMF card provides eight 4-wire E&M trunks. Each 4-wire E&M trunk consists of six physical wires, 4 for speech and 2 for exchanging signalling information with the carrier equipment. This card interfaces with RSC for voice and SPC/ISP for signaling information.

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Fig. 3.2 is the block diagram of the card. The EMF card can be functionally classified into following blocks: • Analog Voice Path • Signalling • Loopback Diagnostics C-DOT 256P RAX

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• Copy Selection and Duplication • Power Supply 3.2.1.3. Two Way Trunk (TWT) Card (Refer Fig. 3.3) This card interfaces with 2-wire analog trunks coming from other exchanges. One TWT card caters to 8 such trunks. Each trunk circuit can be configured as incoming or outgoing or bothway depending upon the requirement. This is done under Software control and a suitable man machine command is available for the purpose. This card too, like other termination cards interfaces with RSC for voice and SPC for signalling. Fig. 3.3 is the block diagram of the card. The diagram shows the division of the TWT card into the following functional blocks:• The 2-4 wire conversion, coding and decoding • The RSC interface • The signalling scan and drive interface • The signalling processor interface • The copy select and the diagnostics • Power supply 3.2.2. Digital Trunk Interfaces The digital trunk interface is either through a: • 30-channel digital trunk unit (RDC/RDS) or • RAX 10-channel Digital Trunk (RDT) card or • RAX WiLL Controller (RWC) Card 3.2.2.1. 30-Channel Digital Trunk Unit (Refer Fig 3.4 (a) and Fig 3.4 (b)) 30-channel Digital Trunk Unit (DTU) is packaged in two cards:• RAX digital trunk CAS card (RDC) • RAX digital trunk Sync card (RDS) The 30-channel Digital Trunk Unit occupies one 32-channel PCM link (one Terminal Group). Since it physically occupies only two card slots, the remaining two card slots of that Terminal Group remain unused. C-DOT 256P RAX

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3.2.2.2. RAX 10-Channel Digital Trunk (RDT) Card (Refer Fig. 3.4 (c)) The RAX 10-channel Digital Trunk card (RDT) is used for the digital trunk interconnectivity between 256P RAXs. It also helps in interfacing 256P RAXs with 6RU10, transmission equipment. The RDT carries the voice & signalling information of 10 subscribers. The RAX 10 channel Digital Trunk card (RDT) operates at 704 kb/s. It can be placed in any termination card slot of 256 RAX. In order to maintain compatibility with termination cards, only 8 out of the 10 channels are used. The maximum number of RDT’s that can be put in a 256 port RAX is limited to eight. 3.2.2.3. RAX WLL Controller (RWC) [Refer Fig. 3.4 (d) ( i), ( ii), ( iii)] RAX WLL Controller Card (RWC) supports two 30-channel digital trunk interfaces each of which can operate either in CAS or CCS mode. This card can occupy slots 10 or 17 of slave frame of 256P RAX because HDLC link towards RSC is available only from these slots. Either one DT or both the DTs can be equipped when this card is used.

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3.3. CONTROLLER CARDS The C-DOT 256 RAX has three types of controller cards: ™ RAX Administrative Processor Card (RAP) ™ RAX Switch Controller Card (RSC) ™ Signalling Processor Card (SPC) / Integrated Signal Processor Card (ISP)

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3.3.1. RAX Administrative Processor (RAP) Card (Refer Fig. 3.5) The RAP card organization can be functionally divided into two blocks: Processor Interface The major constituents of processor interface are memory devices and interrupt mechanism. Paging concept is introduced to accommodate the bulk memory requirement into the 64K address space of the processor 65C02. The total capacity for non-volatile data storage is 128K. In this paged environment, many devices share a common address space and one of them takes over the bus based on selection control done by paging control register. RAP card has provision for six asynchronous data communication links (ACIA). Software timer service is provided by one timer module, which generates periodic interrupts to

the

processor

for

software

timing

purpose.

PCM Clock/Sync Interface A stable 8.192 MHz, 50% duty cycle clock is derived from 16.384 MHz oscillator. The SYNC signal is generated by dividing the selected 8.192 MHz clock through a cascaded counter chain. 3.3.1.1.

A selection logic is employed for selecting one of the

following two clock/sync sources: On board source From duplicate RAP copy The selection control is provided through PIA. Elaborate diagnostics are done for detecting the selected clock presence and frequency check over the SYNC signal is also performed.

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3.3.2.

RAX Switch Controller (RSC) Card (Refer Fig. 3.6)

The whole of RSC organization can be split into the following blocks: CPU Block SPC Interface Switch Block Terminal Interface Message Links Duplication Strategy

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3.3.3. Signalling Processor (SPC)/Integrated Signalling Processor (ISP) Card (Refer: Fig. 3.7) The Signalling Processor Card (SPC) interfaces with the terminal cards on one end and both the copies of RAX Switch Controller card (RSC) on the other. In ISP, the whole circuitry of SP is replaced by an ASIC. The signaling information from the terminations is given to the RSC through a standard 65C02 bus interface. The RSC also programs the SP drive functions through this interface. C-DOT 256P RAX

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3.4 SERVICE CIRCUIT CARDS The C-DOT 256 RAX has four types of service circuit cards: • RAX Multi-Frequency Card (RMF) • RAX Announcement and Tone Card (RAT) • Conference Card (CNF) C-DOT 256P RAX

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• RAX Terminal Test Card (RTC) These cards can be placed in their terminal interface slots.

These

cards also place their digital information on 32-channel PCM highway towards RSC.

3.4.1 RAX Multi-Frequency Card (RMF) (Refer Fig.3.8) RMF card lies in Master Frame of a 256P RAX and services 8 channels per card.

Two such cards can be equipped in system.

This card

receives and generates MF/DTMF tones, as per CCITT specification, for the 8 channels. Input signals like 32 channel PCMIN, card select etc. come from both copy 0 and copy 1 of RSC, the selection of the active copy out of the two is done by card hardware selection logic, which get three signals from each copy of RSC. These signals are Hardware Error, Watchdog and Active/Passive status.

Functionally card is divided as follows: a) Receiver Circuitry b) Generator Circuitry c) Processor Interface Circuitry

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3.4.2 RAX Announcement and Tones Card (RAT) (Ref. Fig. 3.9) The RAX announcement and tones card is one of the termination cards of the system whose function is to send PCM samples of 8 different

tones/announcement to the voice switch (RSC) in a

multiplexed fashion. The tone/announcement PCM samples are stored in the various pages of EPROMs located in the card.

The processor of

the RAT card does the functions of switching between pages to send out the tone/announcement corresponding to 8 channels of 32 PCM link at 2.048 Mbps.

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3.4.3

Conference (CNF) Card (Fig. 3.10) The conference card supports two 4-party conferences.

It

interfaces with the RSC on one of the PCM 32 Terminal Groups (TGs). RSC gives the synchronizing signals for this card. Trunk offering makes use of this card for three party conferences.

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3.4.4 RAX Terminal Test Card (RTC) (Refer Fig. 3.11) The RAX terminal Test card (RTC) is provided in the system to ensure efficient fault detection on subscriber lines/trunks. One RTC caters to the whole system. All subscriber lines and line circuits can be connected to this card through Test Access (TA) bus by operating per channel 4-way relay which is residing in line circuit card.

Under

normal circumstances, the relay is in such a position that the subscriber line is connected to the line circuit (in a Line Card). When a test is required the relay switches and connects the subscriber line and corresponding line circuit to TA bus. RTC is placed in master frame and communicates with both copies of RSC on HDLC link.

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RTC performs the following tests on the termination: a) Subscriber Line Tests with the hand set on hook: • Measurement of foreign voltage (ac/dc) between ‘a’ and ground or between ‘b’ and ground. • Measurement of insulation resistance between ‘a’ and ground between ‘b’ and ground, or between ‘a’ and ‘b’. • Measurement of capacitance across ‘a’ and ‘b’. b) Exchange side tests on line circuits • Origination • Digit reception • Flash reception • Disconnection • Ringing • Answer • Ring Trip • Codec A to D conversion • Codec D to A conversion • Metering pulse • Earth fault • Battery reversal c) For EMF and TWT trunk cards • Seizure • Digit reception / outpulsing • Answer • Metering pulse • Trunk offer • Clear forward • Clear backward • Codec A to D conversion • Codec D to A conversion • Earth fault C-DOT 256P RAX

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3.5 Maintenance Panel (MP) Maintenance panel is an independent unit connected to RAX on ACIA link.

MP is used to carry out various Exchange ‘Operation and

Maintenance’ functions. Maintenance panel unit consists of three cards, Functional description of these cards are as follows. 3.5.1 Maintenance Panel Controller Card The controller card interfaces with the keyboard and display card for accepting keyboard commands and displaying call related information.

Commands

are

formatted

into

messages

and

communicated to RAP through an asynchronous serial Interface. MP is connected to both copies of RAP through ACIA links.

It receives

messages only from the active copy of RAP and in case of any link C-DOT 256P RAX

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failure, MP switches over to the other copy of RAP. Similarly message indicating Call Status/system status are received from RAP and displayed on LCD/LED displays. The console can be functionally classified into following blocks: MPU Logic: The major constituents of Processor interface are memory devices and interrupt mechanism.

Paging concept is introduced to accommodate the

bulk memory requirement into the 64 k address space of processor 65C02. This is achieved by 8-bit paging register. Devices include ACIA, PIA, Timer, Control Register, Paging Register, Keyboard Encoder and Printer Register. ACIA Interface: There are three ACIAs on board, two of which are being used for the interface.

Message generated by the MPU are properly formatted and

transmitted by the ACIA interrupts the MPU. The MPU in turn reads this ACIA and processes the received data. The third ACIA is used exclusively for a remote MODEM interface. All hand shake signals and transmit data are properly sent through a RS 232 link. PIA Interface The PIA is used to control 32 character LCDs on the display card and printer.

All control signals pertaining to the 32 character LCDs originate

from the port B of the PIA.

Port B also provides control signals for the

“Parallel Printer”. Port A is used exclusively for the LCD data. The PIA also handles the Interrupts from the keyboard, printer and the real time clock. All the above three can also interrupt the MPU through the PIA. Timer Interface The timer used has 3 independent, software-programmable counters. All three counters receive the processor clock as input. One counter output is used for the keyboard controller. The second one for the Real Time clock and the third for the buzzer.

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Keyboard Interface A keyboard encoder is used for the Keyboard Interface. The timing for the encoder is derived from the timer.

The encoder drives “Pulses” at

specific intervals on its “drive” lines. When a key is pressed an electrical contact is made between the “drive line” and a particular “scan” line. This generates a “keyboard Interrupt” which interrupts the processor via the PIA. Once keyboard is read by processor, encoder clears the interrupts. At the same instant the ASCII character corresponding to the particular key pressed is output to the display. Diagnostic LEDs There are 48 LEDs on the display card, which are controlled by a LED RAM on the controller. Twelve locations on the LED RAM are dedicated to the LEDs. Each set of 8 LEDs are controlled by the 8 bit data in a particular memory location. Thus, total six bytes of data required for 48 LEDs. However, total twelve bytes of data is used to control these 48 LEDs. The other six bytes of data control the same 48 LEDs for Red colour glowing (the LEDs used are bicolour LEDs with 2 anodes and a cathode). Therefore two controls for a LED serves the purpose of displaying 2 different colours. Printer Interface Printer control signals originate from 1. PIA

-

o/p signals & i/p signals

2. Paging Reg.

-

i/p signals

The Printer “data” is to be latched into a separate “printer Register” which is an 8 bit write only register. The Interface is for a standard parallel printer, which can be used with IBM compatibles. Connectorisation has been done similar to the IBM PC, so that the same printer cable can be used.

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Power Supply Power for the console is derived from an on board power unit. The input (-48V and Gnd) are taken from the system, the out puts being +12V, -12V, +5V and ground. The power unit consists of a regulator for the +12V, one for the 12V and two for the +5V generation, in addition to a switching mode power unit circuitry to convert the -48V to the necessary voltages. The power unit supplies power to the display card too. 3.5.2 Maintenance panel keyboard Card The keyboard card is one of the constituents of the console unit. The card consists of 30 keys each of which is for a dedicated function. Ten keys are for the standard “directory numbers” (0 to 9). The rest are for specified functions like trunk routing, card status display etc. The keyboard encoder on the controller card scans the 30 keys for a “Valid closure” by driving out made between a certain ‘drive’ line and a ‘scan’ line. This is informed by the encoder to the processor by an ‘interrupt’.

The processor on reading the encoder gets the ASCII

character corresponding to the key pressed. The speed of operation depends on factors including debounce time, frequency of the keyboard clock and processors speed. 3.5.3 Maintenance panel Display Card The display card is one of the constituents of the Maintenance Panel/Console unit. The card consists of 48 Bi-colour LEDs, a liquid Crystal Display (LCD) for the visual interface and speaker for Audio Alarm.

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All hardware on the display card are controlled by the S/W residing on the controller card. The hardware does the function of interpreting the signals from the controller into Audio Visual indications. For ease of packaging, the signals from the controller are routed through the keyboard card. Also for the same reason the speaker is made detachable from the display card. The display card is powered by the controller.

3.6 POWER SUPPLY UNIT (PSU) (FIG. 3.12 and 3.13) The Power Supply Card (PSU) generates ringer voltage and various D.C. Voltages required by the C-DOT RAX. The input to the card is -48 V DC which is derived from a float charger & battery set housed outside the system cabinet. The DC-DC converter, which works in switched mode, generates +5V (8A), +12.5V (1A), -9V unregulated (500mA) and -12V (100mA). The available -48V DC from the charger is used by terminal card to provide battery feed. The Power Supply Card (PSU) generates ringer voltage and various D.C. Voltages required by the C-DOT RAX. The input to the card is -48 V DC which is derived from a float charger & battery set housed outside the system cabinet. The DC-DC converter, which works in switched mode, generates +5V (8A), +12.5V (1A), -9V unregulated (500mA) and -12V (100mA). The available -48V DC from the charger is used by terminal card to provide battery feed.

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Functional Description This PSU card can be functionally divided into two parts: i. DC- DC converter ii. Ringer i) DC-DC Converter The DC-DC Converter consists of an inverter, switcher, a ferrite transformer with rectifiers, filters and protection circuits. The low power inverter is used to produce positive voltage from the - 48V for powering the control circuits in the card. The 48V DC input is switched to 20 KHz pulses whose width is controlled by the switcher to keep the final output constant. The pulsed AC is stepped down, rectified, filtered for ripple correction and protected against short-circuit and over voltage, for generating lower DC voltage. ii) Ringer The Ringer converts -48V DC into 75 V AC (RMS), 25Hz with a cadence of 0.4 sec.ON, & 0.2 sec. OFF, 0.4 sec.ON, 2 sec OFF.

75V (ON)

0V (OFF)

0.4S

C-DOT 256P RAX

0.2S

0.4S

2.0S

FIG 3.13 RAX RINGER SUPPLY CHAPTER 1

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CHAPTER 4 SUBSCRIBER FEATURES NOTATIONAL CONVENTIONS BT

- Busy Tone

Conv

- Conversion

DT

- Dial Tone

Flash

- Hook-switch flash (HSF), required for malicious call trace

IND

- Indicating positive acknowledgment (Note: This tone is same as call routing tone)

KW

- Key Word (4 digit secret authorization code)

Service Code

- Service Enable code (valid values are 123 or 124)

Choice Code `

- To select choice for outgoing call restrictions

(valid

values

are

0,1,2,3,4) RBT

- Ring Back Tone

RH

- Replace Handset

LH

- Lift Handset

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Note: To be able to use a feature, the subscriber must be registered with the exchange administration. 1. BASIC SERVICES 1.1

SUBSCRIBER DIALLED CALLS Local, national and international calls can be dialled by the

subscriber. 1.2

PBX LINES; LINE HUNTING This feature allows automatic selection of a free line from a group of lines serving a subscriber on reception of a call to that subscriber’s general directory number. This facility is useful in enquiry services like the Railway, Airlines, etc. or where a group of lines is connected to PBX at the other end. Two types of hunting is possible i.e. fixed head hunt and progressive head hunt. In case of fixed head hunt, the call will be offered to pilot/principal directory number of the group.

If the principal

directory number is busy., the call will be offered to the next member of the hunt group. If the second member is also busy, the call will be offered to the next free available member of the group. For example, directory number ‘P’ is a principal directory no. of a group of fixed head hunt type. Directory nos. ‘A’ ‘B’ and ‘C’ are the other members of this particular hunt group. Then first call to ‘P’ will be offered to ‘P’. The second call to ‘P’, if ‘P’ remains busy will be offered to ‘A’. the next call to ‘P’, if ‘P’ and ‘A’; remain busy, will be offered to ‘B’ and so on. If ‘P’, ‘A’ a and ‘B’ are busy, and when a call is made to ‘P’ and in the meantime ‘A’ becomes free, then call will be offered to ‘A’. Hence, in case of fixed head hunt if principal directory no, is busy, then next call will be offered to next free member in the sequence. Incase of progressive head hunting, if principal directory number is busy, then, further calls to principal directory number will be C-DOT 256P RAX

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offered to one of the member line from the hunt group, which has been idle for longer time. Take the above-mentioned example with progressive head hunt type. ‘P’, ‘A’ and ‘B’ are busy, when a call is made to ‘P’. If in the mean time ’A’ became free, then the call will be offered to ‘C’ instead of ‘A’.

2. RAPID CALL SET UP SERVICES 2.1 HOTLINE 2.1.1 Hot Line without Time-out This feature allows the subscriber to make calls to a fixed destination by just lifting his handset. The subscriber cannot dial any outgoing calls.

In coming calls to a subscriber having this feature,

however, are not affected. The ‘fixed destination’ has to be pre-registered in the exchange. • Feature Usage LH-RBT from distant end 2.1.2 Hot Line with Time - out This feature allows a subscriber to make a call to a fixed destination by just lifting his handset and waiting for a short period of time. In case, the subscriber wants to make a call to a destination other than the fixed destination then the subscriber is expected to start dialing that subscriber directory number before the ‘time-out’. A useful facility, say, for communication between a factory and its registered offices of between two branches of an organization etc. • Feature Usage as Hotline LH - wait for a time out (5 secs) RBT - from distant end • Feature Usage to contact different number

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Lift Handset, dial desired directory no. (dial first digit within 5 secs of lifting handset) RBT from distant end. 3. CALL RESTRICTION SERVICES 3.1

OUT GOING CALL RESTRICTION

3.1.1 Administrative Controlled Restrictions On the request of a subscriber the Telecom administration can prevent all or certain outgoing calls from the telephone of a subscriber. A useful facility for a subscriber if he wants to ensure prevention of misuse of his lines. The feature permits barring of ISD calls, STD call or even local calls. 3.1.2 Subscriber Controlled Restriction This feature allows the subscriber to activate (and later deactivate) prevention of all or certain outgoing calls from his telephone line by following certain control procedures. This facility is completely automatic and requires the subscriber to dial a ‘Service Code’ and ‘Key Word’ (4 digits) followed by ‘choice Code’. ‘Key word’ is a secret code, which the subscriber has to feed himself first time following certain control procedure. ‘Key Word’ can also be changed by the subscriber and is kept secret by the system. ‘Service code’ is basically a three-digit number, (123 or 124 as the case may be). ‘Choice code’ is a single digit number (0 to 4) and is used to allow/bar particular service as explained below. • How to register ‘Key word’ first time: LH - DT- Service code - Key Word - Key Word - IND Service code for invoking this feature is ‘123’ Example: If subscriber chooses its Key Word as ‘1991’ (say) LH-DT 123 -1991 - IND • How to change ‘Key Word’ This facility will be used to change ‘Key Word’ by subscriber himself. Activation C-DOT 256P RAX

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LH - DT - Service Code - Key Word - New Key Word - IND Example: Let us say subscriber want to change his ‘Key word’ from ‘1991’ to ‘1856’ LH - DT - 123 - 1991 - 1856 - IND Service code is ‘123’ for facility. New keyword will become ‘1856’. • How to bar a subscriber line from originating STD/ISD calls: This facility is useful if subscriber wants to bar STD/ISD calls from his telephone and wants to allow local and other calls. Activation LH - DT - Service Code - Key Word - Choice Code -IND Service Code is ‘124’ and choice code is ‘1’ for this facility. Example: LH - DT - 124 - 1856 - 1 - IND • How to bar subscriber line from Trunk booking and originating STD/ISD calls If subscriber wants to make only local calls and wants to bar STD/ISD/Trunk booking. Activation LH - DT - Service code - Keyword - choice Code - IND Service code is ‘124’ and choice code is ‘2’ for this facility’ Example: LH - DT - 124 - 1856 - 2 - IND Note: Emergency Numbers will be allowed. • How to bar subscriber line from originating ISD calls only:

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If subscriber wants to allow Local/STD/Trunk Booking but bar ISD calls Activation LH - DT - Service Code - Key Word - Choice code - IND Example: Service Code is ‘124’ and choice code is ‘3’ for this facility. LH - DT - 124 - 1856 - 3 - IND • How to allow all types of calls: (Deactivating any of the above barring). To make available Local/Trunk bookings/STD/ISD calls Activation LH - DT - Service code - Key Word - Choice code - IND Example: LH - DT - 124 - 1856 - 0 -IND Note: Subscriber should not forget his “Keyword”, he has to contact concerned exchange administration for re-initialization of his code. 3.2 SUMMARY OF OUTGOING CALL RESTRICATION Sl

Service Description

Service

Choice Code

code 1

Registering ‘Key word’ first time

123

-

2

Changing ‘Key Word’

123

-

3

Barring a line from STD/ISD calls

124

1

4

Barring a line from trunk Booking/ STD/

124

2

ISD calls (Except Emergency Calls) 5

Barring a line from ISD calls only

124

3

6

Allowing all types of calls

124

0

124

4

(Local, STD, ISD, Trunk, Emergency) 7

Barring all types of calls (Except Emergency calls)

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4. CALL CHARGE FACILITIES 4.1 CHARGING INFORMATION SERVICES 4.1.1 Subscriber’s Home Meter This feature allows the subscriber to have a meter installed at his premises showing the total call units.

The facility is useful to the

subscribers who want to get an idea as to how many calls have been made so far. This meter operates on 16 KHz pulses. 4.1.2 Detailed Call Charge Recording / Storage / Printout This feature allows the subscriber to get a printed record of all calls (or only long distance calls) made from his line indicating the day and date, the called number, duration and charge of calls. 4.1.3 Subscriber Meter Threshold This feature will set the upper limit on the metering for a subscriber. If the meter exceeds the threshold limit defined, then the subscriber will not get the dial tone. Exchange operator can control the line usage this facility based on the payment status. 4.2 CHARGE DEBITING SERVICES 4.2.1 Coin Box Lines The system has a suitable interface and other provisions so that a special telephone set for which outgoing calls are permitted only after insertion of adequate coins(s) on answer by the wanted party: while, incoming calls are allowed with out payment. Out going calls to certain emergency services may be permitted without payment. For CCB lines, three different types of charging are possible. They are: a) Unit Fee: In this mode the CCB line will be charged only one unit irrespective of duration of the calls.

C-DOT 256P RAX

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45

b) Disconnect: In this mode the call will get disconnected once the

duration for one unit has expired.

(Case of Intra

RAX calls which are not unit fee calls) c) Continue: Same as above except that the call will not be disconnected. It will be treated as ordinary subscriber line. In this case the CCB subscriber will be charged at rate programmed (for that call) at the exchange. 4.2.2 STD Coin Box Lines/STD PCO The system has a suitable interface and other provisions so that a special telephone set which can charge subscriber periodically (for STD/ISD calls) on receiving a 16 KHz pulses from the exchange. 4.2.3 Non-Metered Lines This feature allows installation of certain telephone lines, calls to which are not metered. This feature is useful in certain emergency services like fire, ambulance, etc. for public utility. 5. INFORMATION SERVICES 5.1 LEVEL ONE SPECIAL SERVICES The exchange caters to various requirements of the ‘level one’ services like Trunk Booking, Directory Enquiry etc. Exchange also permits defining certain ‘Level 1’ services as Emergency numbers like; Police, ambulance, Fire etc. 6. MISCELLANEOUS SERVICES 6.1. MALICIOUS CALL SERVICE At the discretion of the Administration. Assistance is given to ascertain the origin of malicious, nuisance or obscene calls. Whenever the called subscriber is registered in malicious call trace category, the exchange stores the identity of calling subscriber (in case of intra exchange calls from exchange having the identification capability) of the identity of the Incoming Junctor (if the distant exchange does not have facility to identify the calling subscriber). C-DOT 256P RAX

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• Feature Usage Conv - Flash HSF during conversation, if malicious call service is allowed on particular subscriber, is indication to exchange that called subscriber needs this call to be traced. 6.2. TRUNK OFFER This facility allows the network operator to interrupt and speak to a subscriber already busy in a conversation. A useful facility for the administration and subscribers, as, it allows the operator to announce an important call. For example, a trunk call is to be offered to a subscriber already busy in a conversation. The option to accept the call from the operator lies with the subscriber. 6.3. QUEUE SERVICE This feature allows the subscriber to have fresh callers placed in a Queue when his line is busy. The service is of particular value to subscribers who have a single number and who do not want to lose call when the line is busy. For example a directory no. ‘A’ having call queue facility is busy in conversation with other subscriber say ‘B’. Now if another subscriber ‘C’ dials ‘A’, then ‘C’ will be placed in queue. ‘A’ will get an indication tone of small duration periodically which indicates that a call is placed in queue. ‘C’ will get either RBT or an announcement indicating that he has been placed in queue. ‘A’, if desires, can discontinue the call with ‘B’ and attend to the call originated by ‘C’. 6.4. CALLING LINE IDENTITY PRESENTATION (CLIP) This feature allows the subscriber to view the calling subscriber number before actually answering the call. This feature is mot useful to these subscribers who receive malicious calls. An additional CLIP display unit or a telephone instrument with CLIP display in which subscriber can view the calling line identity is needed for this feature, along with hardware changes on the corresponding line card. This

C-DOT 256P RAX

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47

facility can be enabled/disabled for a subscriber through exchange administration.

Appendix - A TONES AND ANNOUNCEMENTS 1.0

TONES The following tones are provided in C-DOT 256 RAX: Sl Name of Tone

Freq (Hz)

1 Dial Tone

400+/- 25

Cadence Continuous

2 Busy Tone

400 0.75 s ON/ 0.75 s OFF

3 NU Tone

400 2.8 s ON/ 0.2 s OFF

4 Ring Back Tone

400+/- 25

0.4S ON/ 0.2S OFF/ 0.4S ON/ 2.0S OFF

5 Congestion Tone

400 0.25S ON/ 0.25S OFF

6 Answering Circuit Tone

800 Continuous

Call Routing Tone (Pip7 Pip

Tone)

(Indication

400 01.S ON/ 0.9S OFF

Tone)

2.0

ANNOUNCEMENTS Either English only or English and Regional announcement are possible in RAX which can be selected through MMI. The English announcements available are given below along with mapped tones for each, (in case announcements are not enabled or one announcement card is absent/faulty the corresponding tones will get extended.

C-DOT 256P RAX

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48

Sl

1

2

Context Route Out of Order Number Non Existent

3

Route Congestion

4

Call Queue

5

Bill Not Paid

6

7

Announcement The lines to the route dialled by you are out of order. Kindly try after some time. exist. Kindly confirm the number from

Congestion Tone

NU Tone

directory or consult enquiry operator. All lines to the route dialled by you are Congestion busy. Kindly try after some time.

Tone

Kindly wait. You are in a queue.

Ring Back

Kindly check if you have paid your telephone bill. This facility is not available on your

Available

telephone.

Order

Tone

The number you have dialled does not

Facility Not

Number Out of

Mapped

NU Tone NU Tone

The line to which you have dialled is presently out of order. Kindly dial

NU Tone

after some time. There is no route corresponding to the

8

Route Non Existent

digits dialled by you. Kindly confirm the number from directory or consult

NU Tone

Enquiry Operator.

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49

CHAPTER 5 EXCHANGE OPERATIONS 5.1

GENERAL

The C DOT 256 RAX Operations Manual describes the man machine commands to be used by the RAX Supervisor for Administration, Supervision and Maintenance The commands for performing these functions are divided into seven categories. • System configuration • Subscriber administration • Trunk administration • Routing administration • Billing administration • Maintenance • Miscellaneous Chapter 2 describes the Maintenance Panel (MP) command keys, LCD and LED interpretation. Chapters 4-10 deals in detail with the commands under each of the above seven categories.

A command summary is given at the

beginning of each chapter for quick reference by the supervisor. The commands which result in change of system status/database can only be executed by the supervisor after entering a valid password through MP. This prevents change of important system parameters by unauthorized persons. If any unauthorized person tries to execute such commands, the C-DOT 256P RAX

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50

system will respond with message,

"Access denied; user not logged in".

However, other commands can be executed without entering any password.

5.2 MAINTENANCE PANEL 5. 2.1 GENERAL The 256P RAX Maintenance supervisor can monitor the system status and make changes in it using the maintenance panel. The aim of this chapter is to familiarize the system user with the MP. Fig 5.1 shows the view of the Maintenance Panel. It consists of • 32 Character LCD • LED • Key board

C-DOT 256P RAX

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51

5. 2.1.1

32 Character LCD

This is placed at the top of the inclined panel facing the supervisor for easy readability. The 32 Character display provides diagnostic as well as interactive status message to the supervisor. 5.2.1.2

LED

There are 2 rows each having 24 bi-colour LEDs In the card status display mode, each column of LEDs corresponds to a card.

The frame (Master/ slave) for which card status is being

displayed is indicated on the LCD The LED interpretation is as follows: Top Row LED glowing GREEN

Corresponding Card is PRESENT and ACTIVE

Bottom row LED glowing GREEN

Card is PASSIVE

Bottom row LED glowing RED

Card is FAULTY/ NOT PRESENT

Since PSU cards occupy 2 slots each, slot 2 and slot 26 do not have any LED columns corresponding to them. Therefore the 1st LED column is for slot 1 followed by slot 3 to slot 24, and the last column is for slot 25 (as indicated on the Maintenance Panel). In case of port status display, each column of LEDs stands for one port/termination. Thus status of 24 consecutive ports is shown at a time. The interpretation of LED display in this case is as follows: Top row LED glowing green

The Corresponding port is free

Bottom row LED glowing green

The corresponding port is busy

Bottom row LED glowing red

The port is faulty

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5. 2.1.3

Key Board

It occupies the horizontal plane. This position enables convenient key operation. There are ten numeric keys (0-9) and eighteen command keys.

Of

these eighteen keys, at present on MP only16 keys are used. COMAC key is not represented on the keyboard and will be used in subsequent S/W versions.

SUB

For subscriber administration

TGP

For trunk administration

RUT

For routing administration

MET

For billing administration

TGL

For viewing other options in a menu (toggle)

ABT

For aborting printing

CNFG

For system configuration

MNT

For maintenance administration

RECD

For printing records

MISC

For miscellaneous functions

YES

For selecting option on display

NO

For rejecting option on display

NXT

For going to next item in a menu

PRV

For going to previous item in a menu

TEST

For terminal testing

For various configurations related to MF parameters, Answering Ckt. tests, regional announcements etc. To lock/unlock the keyboard operation in order to enable/disable communication between COMaC and system COMaC through Modem. ('COMaC' stands for 'Centralized Operation and Maintenance Centre for RAX). AUX

NOTE: TGL, YES and NO keys are used to select/change the value for any

parameter. To initiate the change, TGL key is pressed. This causes a display of the next option available for the parameter, along with a question mark. If YES key is pressed in response, the option being shown is selected. If NO C-DOT 256P RAX

CHAPTER 1

53

key is pressed, other options ( if available) are shown. If no other options exist, the original value or option is displayed and retained as such. FUSE: There is a 250 mA fuse mounted on the left side of panel. POWER INPUT: There is a two-pin shell type connector. This connector is inside

the Maintenance Panel cabinet. D-type Connectors: Two 25-pin D-Type connectors are provided on the left side

panel of MP. One of these is used for connecting a modem while the other is used for printer. An RS-232C link cable runs from MP to RAX and terminates on a D-type connector inside the MP cabinet. Reset Switch: A reset switch is provided for giving manual reset to the MP

Controller Card. NOTE: Due to differences in programming from site to site, actual messages

shown in response to an MMI command may vary. The displays shown in this document must therefore be treated as examples used for the sake of illustrating MMI commands. Before defining any parameters in the system, please refer to system Programming Guidelines.

5.3

SYSTEM CONFIGURATION

No. COMMAND 1



KEY

FUNCTION

<1>

Opening Directions (0-9) with one of the following types of analysis: TAX access Y/N 2nd Digit analysis Y/N 1st Digit analysis Y/N DE analysis 2+DE analysis (These options are available on pressing TGL, YES, NO and NXT keys)

C-DOT 256P RAX

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54

2

3

4



<2>

Exchange code



<2>

<1> Add exchange code



<2>

<2> Delete exchange code



<3>

Allotment of routes to a direction



<3><x>

<1> Add route number to Direction X



<3><x>

<2> Delete route number from Direction X



<4>

Card/port configuration change



<4>

<1> Card configuration by Frame no./Slot



<4>

No. <2> Port configuration by giving F/S/T

5



<5>

Restricted STD and Restricted ISD/ primary TAX definition



<5>

<1> Restricted STD definition



<5><1>

<1> Add RSTD code length followed by Route Code and route number



<5><1>



<2> Delete RSTD route code <2> Restricted ISD definition

<5><2>

<1> Add RISD code length followed by Route Code



<5><2>

<2> Delete RISD route code.



<5><3>

<1> PRIM TAX Route Addition



<5><3>

<2> PRIM TAX Route Deletion

6



<6>

Type of day change

7



<7>

Time zone modifications



<7>

<1> Normal day



<7>

<2> Sunday



<7>

<3> Special day



<7>

<4> Holiday



<8>

Trunk Test Port Definition

8

C-DOT 256P RAX

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55

9

10

5.4 No.



<8>

<1> TWT Test Port



<8>

<2> E&M 1 Test port



<8>

<3> E&M 2 Test port



<9>

Miscellaneous configurations



<9>

<1> Announcement Enabled/Disabled



<9>

<2> Record output on Terminal/Printer



<9>

<3> Traffic Recording Enabled/Disabled



<9>

<4> RMF Channel programming



<0>

Self TAX Code Definition



<0>

<1> Add self TAX code



<0>

<2> Delete self TAX code

SUBSCRIBER ADMINISTRATION Command Key

Function

1

<SUB>(Dirno) <1>

Add Subscriber

2

<SUB>(Dirno) <2>

Delete Subscriber

3

<SUB>(Dirno) <3>

H/W Type of a subscriber

4

-do-

<1>

Ordinary Line /CCB Line

-do-

<2>

DTMF phone/Decadic Phone

<SUB>(Dirno) <4>

Facility Type

-do-

<1>

DCR (NIL/Long distance Calls/ All calls)

-do-

<2>

Metered/Non-metered

-do-

<3>

Call queuing allowed/barred

-do-

<4>

Malicious call trace allowed/barred

-do-

<5>

Hotline allowed /Barred; If allowed then with /without time out

-do5

<6>

<SUB>(Dirno) <5>

Non Home-metered/home metered SERVICE TYPE

-do-

<1>

Special Service Allowed/barred

-do-

<2>

Local call allowed barred

-do-

<3>

I/C call allowed/barred

C-DOT 256P RAX

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56

-do-

<4>

Restricted STD allowed/barred

-do-

<5>

STD allowed /barred

-do-

<6>

R-ISD allowed /barred

-do-

<7>

ISD allowed/barred

-do-

<8>

Bill paid /unpaid

6

<SUB>(Dirno) <6>

Display of all above line parameters

7

<SUB>(Dirno) <7>

OG restriction facility

-do

<1>

OG restriction allowed/barred

-do-

<2>

TO reset Password

5.5

TRUNK ADMINISTRATION

NO.

KEY OPERATION

FUNCTION

1



<XX>

<1>

Add a trunk

2



<XX>

<2>

Delete a trunk

3.



<XX>

<3>

Common Parameters



<XX>

<3>

<1>

Line Signalling type



<XX>

<3>

<2>

Register signal type



<XX>

<3>

<3>

TGP type (I/C, O/G or Bothway)

4.

5.



<XX>

<3>

<4>

Operator facility



<XX>

<3>

<5>

Trunk Offer facility



<XX>

<3>

<6>

Manual hold facility



<XX>

<3>

<7>



<XX>

<4>



<XX>

<4>

<1>

Dial Tone feed



<XX>

<4>

<2>

Prefixing digits.



<XX>

<4>

<3>

I/C route category



<XX>

<4>

<4>

I/C charging category



<XX>

<4>

<5>

MF 2 of 6 or 2 of 4 B/W selected.



<XX>

<5>



<XX>

<5>

C-DOT 256P RAX

Display High level trunk group status Incoming parameters.

Outgoing parameters. <1>

Rank of digit

CHAPTER 1

57

6



<XX>

<5>



<XX>

<6>

<2>

Display of all TGP parameters

5.6

ROUTING ADMINISTRATION

No

Command Key

1.



<XX>

Minimum digit seize forward

Function <1>

Add TGP to Route (XX stands for Route No.)

2.



<xx>

<2>

Delete TGP

3.



<XX>

<3><1>

Add route code



<XX

<3><2>

Delete route code



<XX>

<4>

Define Route Parameters.

a.



<XX>

<4><1>

O/G Routing Category

b.



<XX>

<4><2>

O/G Charging Category

c.



<XX>

<4><3>

Immediate release allowed

4.

/barred d



<XX>

<4><4>

Manual hold allowed /barred

e



<XX>

<4><5>

Answer time out YES/NO

f



<XX>

<4><6>

Metered or non metered

g



<XX>

<4><7>

CLI sending enabled/disabled

h



<XX>

<4><8>

Open/closed

numbering

scheme 5.



<XX>

<5>

Route restriction/charge Rate Index (CRI)

6.

a.



<XX>

<5><1>

Route Restriction

b.



<XX>

<5><2>

Charge rate index (CRI)



<XX>

<6>

Display

of

all

Route

Parameters (By pressing NXT Key) 7.



<XX>

<7>

Definition Emergency

of

route

as

Number,

if

allotted to special service Direction. C-DOT 256P RAX

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58

5.7

BILLING ADMINISTRATION

No.

Command KEY

Function

1

<MET><1>

Subscriber meter display

2

<MET><2>

TGP meter display

3

<MET><3>

Total system meter display

<MET><4>

Charge rate index changes

<MET><4><1>

Normal day time zone CRI change

<MET><4><2>

Sunday time zone CRI change

<MET><4><3>

Special day time zone CRI change

<MET><4><4>

Holiday time zone CRI change

4

<MET>

5.8

MISCELLANEOUS COMMANDS

No.

<5>

Display of currently active day and charge

5

COMMAND KEY <MISC> <1>

1

<MISC> <1><XX><1> <MISC> <1><XX><2>

2 3

type

FUNCTION PBX Hunt Group Administration Add a member to hunt group delete a member from hunt group where XX stands for Hunt Group number.

<MISC> <2>

HLG Group Administration

<MISC><3>

Route Restrictions and CRI Modifications

C-DOT 256P RAX

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For route Restriction <MISC><3><1> For CRI <MISC><3><2> <MISC> <4> <MISC> <4> <1> <MISC> <4> <2> 4 <MISC> <4> <3> <MISC> <4> <4> <MISC> <4> <5> <MISC> <5> 5

<MISC> <5> <1> <MISC> <5> <2>

6

<MISC> <6> <MISC> <7>

7

<MISC> <7> <1> <MISC> <7> <2>

8

Password commands Super user PASSWORD LOGIN Super USER LOGOUT User Log in User Log out Change user password Alarm number Add alarm number Delete alarm number Hardware Equipage Maintenance Port Definition Add Maintenance Port. Delete Maintenance Port.

<MISC> <8>

Prom Version, Counter Display

<MISC> <8> <1>

Prom version Display

<MISC> <8> <2>

Counter Display

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60

<MISC> <9>

Calendar Driven RTC Test Commands Enable Line/Exch. Side Tests.

<MISC> <9> <1> RTC Periodic Test On/Off <MISC> <9> <2> 9

Data Entry for Periodic Test <MISC> <9> <3> Display of Data Entered <MISC> <9> <4> Start Hour Programming <MISC> <9> <5> PO of RTC Tests Results. <MISC> <9> <6>

5.9 No.

RECORD COMMANDS Command

Key

1



<1>

2



<2>



<2> <1>

Function Programming of Record Formats: Print Format Definition Traffic Printout Printout of Subscriber traffic for a specified duration Printout of trunk traffic for a



<2> <2>

given HLG and a specified duration

3



<2> <3>



<2> <4>



<3>

C-DOT 256P RAX

Printout of Traffic dispersion for a specified duration Printout of exchange traffic for a specified duration Malicious call record/DCR CHAPTER 1

61

printout

<3> <1>

MCR printout Malicious call record printout

<XXX>

for a given subscriber dir no.

<3> <1> <1>

XXX <XXX>

5

6

7

MCR printout for a given month and date

<3><<1><3>

MCR printout of some specified



records



<3> <2>

Detailed call record printout

<XXX>

<3><2><1>

<XXX>

<3><2><2>

<XXX>

<3><2><3>

DCR Print out of some specified



<4>

Meter Po-Sub/TGP/Exchange



<4> <1>

Printout of sub meter



<4> <2>

Printout of TGP meter



<4> <3>

Printout of Exchange meter



<5>



<5> <1>



<5> <2>



<6>



<6> <1>



<6> <2>



<7>

<XXX>

4

<3> <1> <2>

C-DOT 256P RAX

DCR printout for given sub. Dir. No. XXX DCR Printout for specified month and date

Printout of Dir to Port /TGP to Port Directory to port mapping printout Printout of TGP No. to port No. Mapping Printout of TGP to route No/ HLG to TGP Printout of TGP to route mapping selected Printout of HLG to TGP mapping selected Printout of RTC test result Exchange/Line/CLT CHAPTER 1

62

Print outs of exchange side test



<7> <1>



<7> <2>



<7> <3>

Printout of CLT results selected

8



<8>

H/W Equipage Printout (Y/N)

9



<9>

Periodic Print-out - DCR /Traffic



<9> <1>

Periodic DCR Printout



<9> <1> <1>

DCR Periodic Printout On/OFF



<9> <1> <2>



<9> <1> <3>



<9> <2>

Periodic printout Traffic



<9> <2> <1>

Traffic Periods Printout Off/On



<9> <2> <2>



<9> <2> <3>

results Printouts of Line side results selected

Periodicity in Hours for DCR periodic printout Start time for DCR periodic printout

Periodicity in Hours for Traffic Periodic Printout Start time for Traffic Periodic printout

5.10 AUXILIARY COMMANDS No.

Command Key

Function

1

<1>

Country adaptation parameters

2

<2>

Miscellaneous Parameters

<2><1>

English and regional announcement

<2><2>

PC/on line monitor mode

<2><3>

Intra RAX call meter rate

<2><4>

Subscriber block configuration

<2><5>

CCB Subscriber options

<3>

Answering circuit

3

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4

<3><1>

Two wire ans. ckt. no.

<3><2>

Four wire ans ckt no.

<3><3>

Ans ckt for TGP’s

<3><4>

TGP Nos.

<3><5>

Ans. ckt. periodic test

<3><6>

Ans. ckt test results

<3><7>

Ans ckt test on command

<3><8>

Ans.ckt start time programming

<4>

RMF tests

<4><1>

RMF periodic tests

<4><2>

Printout of RMF periodic tests

<4><3>

Periodic RMF tests start time

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CHAPTER 6 START UP PROCEDURE

6.1 START UP PROCEDURE Following steps should be observed while switching on the RAX:

• Before switching the system ON check that the battery sets are fully charged. • Check that Green LEDs on both the PSU cards of two frames light up. • Put all the four PSUs ON. • The display on the maintenance panel should be ‘Duplex Copy 0 Active’ after some initial message “RAP X Link Failure”. • Press the ‘reset’ button on the RAP card in the card slot 14 of master frame. (This would reset the card and update the information with the one stored in copy 0 of RAP so that both the cards will have the same information).

6.2 EXCHANGE DATA PREPARATION Before the site specific installation can be started, the following details are to be furnished by the planning wing of respective circle or district of BSNL as the case may be. i) Trunking requirement for networking with existing exchanges.

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ii) Numbering plan for the proposed exchange along with capacity requirements at the time of cutover, proposed expansion and the ultimate capacity expected. iii) List of exchanges presently working in the network, their type and make, list of exchanges in network expected to be closed down within next three years. iv) List of exchanges expected to be installed in the network in next three years. v) Routing details for various directions along with trunk grouping. vi) Following details are available for outgoing, incoming and transit routes. *

Direction codes

*

Trunk groups with constituent directions (routes)

*

Line signalling

*

Register signalling

*

Number of trunks in each trunk group

*

Rank of digit

*

Number of digits expected from I/C routes

*

Alternate routes

vii) Number of subscribers and hardware facilities and service type to be provided to each subscriber. 6.3 PROGRAMMING Once all the cards are jacked in and system is powered on then, one should do the programming as follows:

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i) Login as user & define unique Super user password for the system. ii) First of all each card slot is to be configured according to cards placed in the slots. Type and number of cards to be used of each type depends upon the data collected in previous section. iii) Add exchange code. iv) Open the level/directions required for networking that particular exchange and program the digit analysis for each opened directions/level. v) Set the date, day and time of the exchange. vi) Add the subscribers according to the plan already made (i.e. which subscriber is to be added to which frame/slot/circuit). Give the required facilities and services to each subscriber.

vi) Make trunk groups according to requirement and add the circuits to the trunk groups. Set the parameters of the trunk group according to the type of the trunk group (i.e. incoming, outgoing and bothway) and program the rank of digits, signalling type, etc. vii) Create a route, add it to required level and add the relevant trunk groups to the route. Program the charge categories and route categories and other parameters.

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ix) Program the route restriction (i.e. can a call coming from one route category go to other route category). x) Program the charge rate index according to the metering required. Program the charge rate matrix/table for each type of day (i.e. normal, Sunday, special and holiday). xi) Test line to line call and call to each direction incoming as well as outgoing. xii) RAX is installed & ready for use.

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CHAPTER 7 FAULT HANDLING 7.1 GENERAL The C-DOT 256 RAX provides several maintenance features for fault maintenance in the system. Though the duplication of critical control circuitry makes the system highly reliable, in case of failure of any system element, the maintenance personnel can isolate the faulty module and take the appropriate corrective action with the help of these features. The various maintenance features are listed below: •

Remote monitoring with tones

•

Alarm reporting on alarm number

•

Automatic diagnostics *

Online self diagnostics to run on all controller cards

*

Bootup diagnostics for controller cards

*

On-line routine local diagnostic tests

•

On command diagnostics

•

Automatic system recovery

•

Status Fault reporting *

System active, passive, faulty indications

*

Terminations free, busy, faulty/blocked

•

Established calls retained on plane switch over

•

Control sanity check *

Watch dog cross connections

*

Sanity punch messages

*

Communication link checking

•

Fault recording for controller faults

•

System Switchover in case of fault

•

Forced copy changeover

•

Line and trunk tests

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*

Line and trunk testing on demand

*

Calendar driven line/trunk testing

*

Answering circuit tests (demand/period)

*

Flashback test

7.2 REMOTE MONITORING WITH TONES It is possible to monitor the system from a remote place by dialling Remote Monitoring Number - a predefined directory number which can be dialled to know the status of the system. This number is represented by ‘EXC00’ where EXC is the exchange code ranging from 1 to 5 digits. The system has provision to feed a series of different tones corresponding to the existing faults to the caller when this monitoring number is dialled from a remote exchange. For example: If the system is in ‘Battery Low Condition’, then the sequence of tones fed would be Silence Tone 3 sec. NU Tone 6 sec. (indicating Battery Low Condition) Ring Back Tone 30 sec.

In case there is no fault in the system the caller would be fed with ring back tone after the initial silence of 3 sec. Ring back tone marks the end of tone-feeding sequence. 7.3 ALARM REPORTING ON ALARM NUMBER Alarm reporting number is defined through man-machine commands to any of the subscriber’s port. In case of any system fault, system extends alarm in the form of ring to this predefined number and feeds suitable tone/ announcement on answer. The tones are same as those heard on dialing remote monitoring number.

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7.4 ON COMMAND DIAGNOSTICS On command diagnostics can be performed on the following cards to verify proper functioning of these cards: a)

RMF card Each block of four channel can be tested by running diagnostics on channel of that block.

b)

DT30 Both the units (30 channel) can be tested by running diagnostics on Master frame DT30 & slave frame DT30 individually.

c)

RWC Diagnostics on DTs equipped in RWC card can be run individually through command.

d)

RAT Card The functioning of RAT card can be test by running diagnostics on RAT0 and RAT1.

e)

RTC Card Idle time diagnostics can be initiated on RTC card to check its working.

f)

CNF Card Voice path test is conducted on CNF card during diagnostics.

7.5 AUTOMATIC SYSTEM DIAGNOSTICS The system conducts automatic diagnostic tests during: •

Bootup (for Controller cards)

•

On-line (for Controller cards, MP, RAT, RMF and PSU)

7.5.1 Bootup Diagnostics for Controller Cards On system initialisation RSC (Master) performs checks on its links with other controller cards and gets details of duplicate copy controller card from duplicate RSC (Master).

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7.5.2 On Line Local Diagnostics for all Controller Cards, MP, RAT, RMF and PSU The controllers continuously runs the required self diagnostics program to monitor the health and keep the next higher controllers informed about their healthy status. 7.6 SYSTEM RECOVERY During duplex working, whenever the system encounters any failure in one of the copies at any stage, it will go to simplex state. Duplicate copy will run the diagnostic program if required to identify the faulty unit and cause suitable audio-visual alarm and printouts. The system will continue to run diagnostic tests on the faulty unit and if it is discovered that the unit has returned to its normal healthy state, the system will then automatically bring back the unit into service and remove the alarm conditions. However, recovery sequence for dumping all the data in active copy to passive copy for making the system duplex active will start only if super user has logged in already and resets the passive copy controller. 7.7 STATUS DISPLAY/FAULT REPORTING All the control cards, tone generation circuits and power supply units are duplicated in the system. One copy of the cards is active at a time while the other is passive. Both the PSUs are active unless there is a problem with the PSUs, and share the load of the system. On the maintenance panel, the 24 LEDs display the Active, Passive and Faulty status of the cards. In case of active cards, status is shown by top row LED glowing green. Similarly, for passive, it is shown by bottom row LED glowing green and for faulty cards, bottom row LED glows red. Similarly, the presence or absence of cards are also shown by green and red glow of LEDs correspondingly. 7.8 STABLISHED CALLS RETAINED ON PLANE SWITCHOVER As mentioned earlier, all the control cards viz. RSC, RAP, SP and PSU cards are duplicated. The two copies of each card in either frame (master C-DOT 256P RAX

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and slave) are designated as plane 0 and plane 1. For eg. Plane 0 includes RAP0 (Master), RSC0 (Master), SP0 (Master), RSC0 (Slave), SP0 (Slave) and Plane 1 includes

RAP1 (Master), RSC1 (Master) SP1 (Master), RSC1

(Slave) SP1 (Slave). Now, whenever there is any fault in any copy of any card, then system switches over from one plane to other. While switching over, the calls that have already been established are not lost in the transition. 7.9 CONTROL SANITY CHECK Certain faults like software error resulting in the program entering an endless loop, processor clock failure etc. are very dangerous for the overall operation of the system. It is very important to detect such faults. It is for this reason the system performs certain checks on its own to ensure proper functioning of the system. 7.9.1

Sanity Punch Messages Sanity messages are sent and received between all the processors at regular intervals. If sanity message is missed from a processor, then its sanity is doubted by the other processor and this will lead to system switch over.

7.9.2

Watchdog Signals Check The watchdog signals between RSCs and between RSC and RAP are checked by both RSCs. Any fault in watchdog signals will result in system switch-over to SIMPLEX state.

7.9.3

Communication Link Check When the message rate between processors is low, the communication links are checked by sending link check message and receiving acknowledgment. Communication link fault can lead to system switchover. When system is in DUPLEX, both RSCs will be checking RSC-RAP link and the

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RSC-RSC link. When the system is in SIMPLEX, the active RSC will check RSC-RAP link only. 7.10 FAULT RECORDING FOR CONTROLLER FAULTS A fault directory is maintained for the most recent 32 controller faults with date & time of occurrence and fault details. Details can be seen for most recent fault or by entry number. 7.11 SYSTEM SWITCH OVER IN CASE OF FAULT Duplication of control cards ensures detection and isolation of faults without allowing them to propagate. Occurrence of faults in control cards (RAP, RSC, SP) will result in system switchover from DUPLEX to SIMPLEX. Fault in RAT will result in a changeover from faulty card to duplicate card which will act in tone mode only. 7.12 FORCED COPY CHANGEOVER Forced changeover occurs after every 24 hours or on giving MMI command. The duplex active copy becomes duplex passive and vice versa and the system recovers in duplex mode. 7.13 LINE AND TRUNK TESTS Two types of tests are done by the RAX Tester Card (RTC) i.e. line side tests and exchange side tests. 7.13.1 Line Side Tests The following tests are performed on the subscriber lines by the system with the help of RTC card. The testing can be done either on demand or can be calendar based from subscriber premises with or without operator’s assistance. A subscriber line can be tested when the subscriber is on-hook or when the subscriber in conversation mode with a maintenance number. The above two modes of testing a subscriber line are discussed below: C-DOT 256P RAX

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7.13.1.1.

Terminal Open Loop Tests The following test details are available for a subscriber line when tested with a subscriber onhook:

7.13.1.2.

*

AC/DC Voltage tip to ground

*

AC/DC Voltage ring to ground

*

Insulation between tip ‘a’ and ground

*

Insulation between ring ‘b’ and ground

*

Insulation between tip and ring

*

Capacitance between tip and ring

Terminal Closed Loop Tests The following tests are available for a subscriber with decadic or DTMF dialling facility and in conversation with the maintenance number: i)

ii)

Subscriber with Decadic Dialling Facility *

Loop current measurement

*

Loop resistance measurement

*

Break duration

*

Make duration

*

Break/make ratio

*

IPS (Impulses Per Second) measurement

*

No. of pulses received

Subscriber with DTMF Dialling Facility *

Loop current measurement

*

Loop resistance measurement

*

DTMF keypad test

While carrying out the line side tests, it is possible to extend speech path to the designated maintenance telephones so that if testing is being done on demand then the maintenance supervisor can also talk to the subscriber and ask him to dial a particular digit to perform dial testing etc. Suitable command (test command) sequence are there to conduct

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the above test. 7.13.2 Exchange Side Tests Exchange side tests can be performed on subscriber lines and analog trunks only. These can be done on demand, or on a calendar driven basis. The following exchange side tests can be made and the details are available for subscriber lines and analog trunks by the system: i) For Subscriber Lines/Coin Collection Box Lines * Origination * Digit reception (also available for TWT/E&M trunks) * Flash reception * Disconnection * Answer (also available for TWT/E&M trunks) * Ring trip * Codec A to D (also available for TWT/EMF trunks) * Codec D to A (also available for TWT/EMF trunks) * Earth fault (also available for TWT/EMF trunks) * Meter pulse (also available for TWT/EMF trunks) * Battery reversal ii) For TWT/E&M Trunks *

Seizure

*

Outpulsing

*

Trunk offer

*

Clear forward

*

Clear backward

7.13.3 Answering Circuit Tests Answering circuit tests for two wire and 4 wire trunks are supported. Automatic tests can be performed by the C-DOT 256P RAX

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systems at a pre-programmed time each day. On-command initiation of tests is also possible. Required number of RMF channels can be equipped as Answering ckt. channels through MMI commands. 7.13.4 Flashback Tests System responds to Flashback tests initiated by remote exchange. (For TWT,E&M and ring down trunks). 7.14 CALENDAR DRIVEN TESTS 7.14.1. Calendar Driven Line/Exchange side Tests Range of ports to be tested and the time of starting the test can be programmed through MMI. At the specified time each day, these ports will be tested one by one. Any errors reported will be printed spontaneously. Default time for cal. driven RTC is 01 hours. 7.14.2. RMF Periodic Tests This test is at 02:00 hours by default. All RMF channels are tested and results printed. The test time can be programmed as desired. 7.14.3. Answering Circuit Tests Start hour can be defined for these tests. The system will carry out the tests and print the results each day.

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CHAPTER 8 256P RAX INSTALLATION 8.1 SITE PLAN This chapter provides general information about site planning before the installation of C-DOT 256 Port RAX system. The main requirements are: •

Floor space

•

Environmental conditions

•

Power supply

A typical layout is shown in Fig. 8.1. Before the installation of C-DOT 256 Port RAX system, the site should be made ready with the following:

2.5

3.5 MDF TE

BATTERY.1 R A

3.5

F BATTERY. 2

C

FIG 8.1/ A TYPICAL 256P RAX LAYOUT

C-DOT 256P RAX

TE: TRANSMISSION EQUIPMENT FC: FLOAT CHARGER

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8.1.1. Floor Space The system needs an enclosure of 3.5m x 3.5m with a ceiling height of 2.9m to accommodate the system cabinet, a table on which MP and printer are placed, the power supply source or the Float charger, the Main Distribution Frame and the Transmission Equipment (if necessary). For the battery sets, a separate room of 2.5m x 2.5m is required as it releases the acid fumes which would corrode the other equipments if placed in the switch room. 8.1.2. Environmental Conditions The switch room, where the system and other equipment are installed should be cool and dust free. The illumination should be 300 lux or 2 numbers of paired fluorescent tubes should be made available, placed with a gap of 1.5m between them. The battery room should be well ventilated to clear the acid fumes released by battery sets. The walls and the woodwork should be given acid resistant coating. The floor of the battery room should have a drain to clear the acid spills. The battery sets should be placed in such a way that no direct sunlight falls on any of the battery sets.

8.2 ELECTRICAL SPECIFICATIONS The C-DOT 256 RAX system requires uninterrupted -48V DC supply derived from single-phase 50Hz 230V ± 10% commercial AC supply. The power plant is of float type with float rectifier-cum-charger which floats two sets of 24 cell and 120 AH each, lead acid batteries across its output. C-DOT 256P RAX

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The output of the battery should be able to supply power to the system and to the transmission equipment if required. The float charger should accept 230V ± 10%, single phase, 50Hz AC supply as input and provide 48V DC at the output. On failure of the mains supply the battery sets deliver the power. On restoration of mains, the float charger would not only supply power to the system (s) but also charge the battery.

8.3 EARTHING SYSTEM A perfect earthing should be provided mainly to ensure: • Reduction in cross talk and noise in the telecommunication circuits; • Protection of the system against dangerous foreign voltages; • Protection of person and plants against leakage from station power wiring to metallic apparatus, frames etc. There are many earthing systems adopted by the telecommunication department. One of the earthing systems is adopted depending upon the type of soil resistance. The prime requirement is the earth resistance and it should not exceed 2 ohm even at extreme conditions. Some of the Earthing Systems which are commonly employed are:

i) Spike Earth Electrode System: This is generally provided at all new automatic exchanges where adequate space is available around the exchange and where sub soil is suitable for driving in the pipes to a depth of 375 cms. ii) Lead Strip Electrode System: This type of earthing system is employed where adequate space is available but rock is encountered in less than 375 cms from ground level. C-DOT 256P RAX

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iii) Earth Plate Electrode System: This type of earthing system is employed when the layout of the exchange site is such that adequate space is not available to install. The earthing cable, a Bare Tinned Copper (BTC) wire of 19/1.6mm or 100/300 lb copper wire or 7/16 cable with red insulation should be terminated on a copper bar of 25mm x 6mm x 200mm (typical). The copper bar also called Earth Bus Bar should be placed close to earth pit. The Earth Bus Bar is fixed to the wall at a convenient height by means of screws but insulated from the wall. This bus bar would be the reference for all the grounds provided in the system. See Fig. 3.2 for the various terminations on earth bus bar.

FROM RAX EARTH BUS

POWER MDF PLANT COMMON (DC

EARTH

TRANS EQPT

FIG 8.2 EARTH BUS BAR

8.4 LOCAL PURCHASE ITEMS AND TOOLS The items to be procured locally at site by the local authorities are listed in Table 3.1. Make sure that these locally procured items are made available before the starting of Installation. C-DOT 256P RAX

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8.5 EQUIPMENT PLACEMENT The RAX cabinet, the float charger and the transmission equipment should be placed at least 1m away from the wall to ensure comfortable system installation and maintenance. Fix the locations for the various units in the switch room and if necessary, mark the location using the following guidelines: • Fix the location of the MDF. It has to be fixed onto the wall. It is preferable to have the MDF close to the earth bus bar and external cable inlet. The distance between the system and the MDF should not exceed 5m. • A Miniature Circuit Breaker (MCB) for a single-phase 230V ± 10% AC should be provided near the location of the float charger. • Run the PVC conduit (square or circular cross section) of 60mm side or dia from the location of RAX cabinet to the power plant, MDF, earth bus bar and the battery. • Run PVC conduits from transmission equipment to the MDF. • Similarly, run another cable (7/16 cable with red colour insulation) with one end terminated on the Earth Bus Bar and the other end left free near the location of float charger. • Run a cable (7/16 cable with red colour insulation) terminating one end on Earth Bus Bar and leaving the other end free near the location of MDF. • Bring the external cables through the PVC conduits and leave them free near the location of MDF. • Run the cable from the transmission equipment to the MDF through the PVC conduits.

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TABLE: 3.1 LIST OF LOCALLY PROCURED ITEMS Sl.

Material Description

Quantity

1

PVC pipes – 63 mm Dia.

6 to 7 metres

2

PVC Elbow Bends – 63 mm

4 Nos.

3

PVC Tees – 63 mm

2 Nos.

4

PVC pipes 2 or 3 bends

5 6

3 to 4 metres, 2 or 3 Tees & Fixing Clamps

PVC pipes and bends 40 mm for

Site-dependent the

extending

battery cables

MCB 15A 2-Pole (Phase & Neutral)

1 No.

3-Core 15A flexible copper cable for 7

extending the AC Mains to the Power

3 to 5 metres

Plant 8 9

Cable – 7/16 copper wire with (i) red insulation and (ii) blue insulation HRC Fuses 25A for battery output

10 m each 2 Nos.

Earth Bus Bar (tin-coated copper) of 10 dimension 25 x 6 x 200 mm. with fixing

1 No.

bolts and supports drilled with 7 holes 11 Metallic Plinth/ Cement Plinth 12 Crimping Lugs – 16 Sq. mm.

22 Nos.

13 Hand Crimp Tool

2.5 to 16 Sq. mm.

14 Cutter & Wire Stripper and Knife

One each

15 Cable tie 150 mm

1 Pkt (100 Nos.)

16 Screw Driver small

1 No.

17 Spanner Set Small

1 Set

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8.6 SYSTEM INSTALLATION 8.6.1 GENERAL The second consignment at the site comprises the following items packed in wooden cartons and CFB boxes. • Cabinet (Card cage, PDP etc. fitted) • Cards (in more than one box) • Maintenance Panel & Printer • Cables These items must be available at the site before starting installation of the system. The tools that are required at the site are quite minimal but are essential. These include: • Spanner set • Hammer (5 kg.) • Rawl jumper with bits M5, M10 • Wire wrapping tool • Crimping tool • Lugs with 5mm dia holes etc. 8.6.2 UNPACKING THE CABINET To unpack the wooden carton containing the cabinet, follow the steps given below: • Keep the wooden carton containing the RAX cabinet in upright position and remove the front cover by removing bolts (or nails if it is nailed). • Remove the packing material from all sides and slowly pull the unit out. • Remove the polythene cover over the cabinet. 8.6.3 VISUAL INSPECTION • Check the cabinet from all sides for dents, damages etc. • Open front and the back doors and check that there are no loose components or damages. C-DOT 256P RAX

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• Check that cables are intact and the cable layout is undisturbed. • If there is any inconsistency found during visual inspection, inform the manufacturer for proper placement or replacement. • Check the card cage frames for their rigidity and alignment with respect to the cabinet frame. • Check that the motherboards are rigidly fixed to the card cage frame. • Check that all the connectors are available corresponding to all the slots. (on slot position 26A and 26B the connectors are not provided) • Check that no bare or open-ended wire is hanging on the motherboard. • Check that PDP is fixed firmly at its place. • Check that the Fast-on connectors are fully inserted into the tabs on the mother board (This ensures 48V on the mother board.) • Check that all the inter-frame cable connectors are firmly fixed to the male connectors on the backplane. The cable markers are given above every connector of these cables. Ensure that cables are placed at their proper places. In case these are supplied separately, place these on the proper positions at backplane. • Check the connectors for any damage on the back plane. 8.6.4 ASSEMBLING THE CABINET After unpacking and visual inspection of the cabinet following steps are to be followed for assembling: • Installant has an option of putting the plinth below the RAX. Four holes are to be drilled on the floor, according to the plinth (if plinth is to be used) or else according to the RAX cabinet. • Place the screws (if plinth is used then use screws defined for plinth, if not, use screws which are to be used for RAX) in the

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holes, fix them with plugging compound and let it dry for some time. • Place the plinth/RAX over the screws and use nuts to tighten the plinth/RAX. • If using plinth then put the RAX on the plinth (after fixing plinth as in above step) and use nuts and bolts to tighten the RAX. • After fixing RAX, place the false panels and fix them. 8.6.5 UNPACKING THE MAINTENANCE PANEL/PRINTER • Cut the straps of the CFB box and open the box. • Take out the Maintenance Panel/Printer unit from the box and remove the polythene cover over it. Place the unit on the table near the cabinet. • Preserve the box, as this is reusable for transportation during maintenance or obtaining spares. 8.6.6 SYSTEM INTERCONNECTIONS Get the subscriber/trunk cables, prepared according to the configuration and route them through left and right side trays (refer section 6.3). One end of each cable is to be connected to the respective mating sockets on the back plane. Other ends of the cables are to be properly routed to MDF 8.6.6.1 System Earthing * Connect GGR4 cable on RAX master bus bar fitted on bottom panel at rear side of RAX cabinet. * Run the wire through the cable entry and cable clamps. * Run the wire through the PVC conduit upto the earth bus bar. * Terminate the wire on the earth bus bar. 8.6.6.2 Power Supply Connection Terminate the wires which are extended from the power plant as follows: C-DOT 256P RAX

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* The Black wire should be terminated on -48V point on PDP. * The Red wire should be terminated on GND point on PDP. * Check that power supply connections and groundings are proper. 8.6.6.3 Peripheral Unit Interconnections MP is to be placed on table and two cables - MP power cable and MP interface cable, coming out of RAX will be terminated on MP. Connect a suitable 80/132 column Industry Standard Printer. 8.6.6.4 Exchange Side Terminations on MDF * Insert the MDF cables into the cable entries (left hand side cables on LHS cable entry and right hand side cables in RHS cable entry) and pull them out through cable clamps. * Run the cables through PVC conduits upto the MDF. * Cut the cables of required length with margin. * Lace the cables properly onto the MDF structure. The a- and b- wires from the subscriber’s side are terminated on the adjacent columns of this connector block and the corresponding terminals in that column are left free in order to accommodate the jumper wire coming from the other connector block. The subscriber lines are connected to the RAX by providing this jumper. Single strand, multi pair cables should be used for making the connections on these connector blocks. The tags on these connector blocks automatically strip the insulation from a wire and make contact with it when a wire is inserted into it. In order to terminate the wires on these connector blocks, use the insertion tool provided with the installation tool kit and proceed as follows: * Take the first 32 pair cable. * Remove the PVC insulation and terminate the 8 pairs which have white transparent polythene wrapper on the connector module pertaining to the subscriber/trunk lines. C-DOT 256P RAX

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• The next three units with polythene wrapper yellow, brown and blue should be terminated on their respective connector blocks. 8.6.6.4.1. Termination of 8 Pairs Unit Termination of 8 pairs unit on the MDF should be done as follows: * Route the cable such that the cable enters through one of the cable inlets on the back mount plane frame. * Remove the insulation, fan out the other units (A unit consists of 8 pairs of wires and wrapped with a coloured transparent polythene). * Take the first unit, unwrap the wrapper. * Place the connector module in its location. Place the wires in the same order as designated. * Using the insertion tool insert the conductor into the slots of connector module. * After completing the terminations on one connector module place the next connector module, insert the conductors into the slots using the same tool. 8.6.7 MDF Terminations for Different Configuration The RAX can be configured in three different configurations. The configurations are as follows: C-DOT 256P RAX

Configuration Details Sl.

Configuration Type

Line Cards

CCM Cards

TWT Cards

EMF Cards

Digital Trunk

1

181 Lines 1 Digital Trk (30-channel each)

A

19

4

-

-

1

2

120 lines 3 Digital Trk (30-channel each)

B

12

3

-

-

3

3

56 Lines 5 Digital Trk (30-channel each)

C

5

2

-

-

5

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8.6.8 Connections for RNS Card RNS card can be put in any free termination slot, preferably next to the digital trunk card (RWC or RDS) on which the reference PCM link for synchronization in terminated. The reference PCM link is to be terminated on the DT card & RNS in parallel. Using cable ACBRNSXDTRX-000 cable. Also synchronized o/p from RNS is to be fed to both copies of RAP through another cables ACB-RNSCKSCX-000

8.7 RAX SETUP • Open the box consisting of all the cards. Pull out the card from the individual box and insert into the card cage frame with connectors facing card frame and components facing your right hand side. • A typical configuration of RAX is shown in Fig. 5.5, after inserting all the cards (Printed Circuit Boards). • If CCB subscribers are existing, one of the line cards can be replaced by a CCM line card. (The CCM equipped in any trunk card slot, used as ring down trunks, cannot be used for CCB subscribers). • If STD-PCO subscribers are existing, then one of the line cards can be replaced with CCM card. Only last 2 ports of CCM card i.e. 7th and 8th port have provision to extend the 16 KHz pulses. Rest of the ports can be used for CCB subscribers.

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TG 5

P S U 0

1

P S U 0

2

TG 6

COPY 0

T C

T C

T C

T C

T C

T C

T C

T C

S P C 0

3

4

5

6

7

8

9

10

11

T C

T C / C N F

R A T 0

T C / R M F 0

T C

T C

T C

R T C

TG 1

S P C 0

TG 2

FIG: 2.3

R S C 0

12

R S C 0

13

R A P 0

COPY 0

COPY 1

14

R A P 1

TG 7

TG 8

R S C 1

S P C 1

T C

T C

T C

T C

T C

T C

T C

T C

P S U 1

15

16

17

18

19

20

21

22

23

24

25

S P C 1

T C / R M F 1

R A T 1

T C

R D S / T C

T C

R D C / T C

P S U 1

R S C 1

COPY 1

T C

TG 3

T C

TG 4

256P RAX CARD FRAME

IMP. NOTE: • By just placing CCM card in a slot does not mean that those services will be provided unless that particular slot is programmed CCB line with home metering facility. • For ring down facility use TWT/CCM card - the slot for which can be programmed for ring down. • Open the other box which consists of PSU cards. Pull out the cards and insert into slot 1 and 25 of master and slave frame. Before inserting check that the switches are ‘OFF’. • If ‘trunk offer’ is required at a particular site then Conference Card (CNF) is must. CNF card can be placed in 7th slot of Master Frame. However, if ‘trunk offer’ facility is not required then this slot can be used for placing any Line/Trunk Card. Conference Card provides facility for 3 party conference i.e. simultaneous conversation between two subscribers and an operator. C-DOT 256P RAX

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S L A V E

26

M A S T E R

C-DOT 256P RAX APPENDIX - A SPECIFICATION SUMMARY Control

65C02 Microprocessor-based SPC

Network

4-wire Non-blocking PCM

Capacity Traffic

Maximum 256 terminations including subs, trunk and service circuits 4000 BHCA 0.2 Erlangs for line 0.6 Erlangs for trunks

Transmission Tones

CCITT Standard Dial, Ring Back, Busy, NU, Congestion, Routing, Idle and Answering Circuit Tones Route out-of-order, Route or number non-existent,

Announcements

Route congestion, Queue, Bill Not Paid, Number out-of-order, Facility Not Available

Signalling

Decadic/ DTMF Subscriber signalling Decadic/ MF Digital trunk signalling

Termination

Normal subscriber lines Coin Collection Box lines/ STD CCB lines 2-wire physical loop circuits 4-wire E&M circuits 30-channel digital trunks 10-chanel digital trunks

Loop Resistance

Subscriber Lines – 1200 Ohms Trunk – 1500 Ohms

Ringing

75V, 25Hz with an interruption rate of 0.4 sec ON/ 0.2 sec OFF/ 0.4 sec ON/ 2 sec OFF

Termination impedance

600 Ohm complex

Insulation Resistance

20 K Ohm maximum

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Numbering Scheme

Flexible 4 to 7 digits, block numbering 4 modes of charging each divided into 9 time

Charging Scheme

zones. 8 different charging rates in each time zone. Intra-RAX call charging Individual software meters for all subscribers,

Metering Scheme

giving itemized and total bill. Separate Revenue Meters for Trunk Groups and for aggregate charging done in the system. Detailed traffic measurements related to

Traffic Analysis

subscribers, trunks, service circuits and the aggregate.

Test Reports Printouts

Subscriber Features

Reports on lines, trunks and MF Senders/ Receivers. Spontaneous, on command and periodic printouts on system status and records. Normal/ Subscriber/ CCM Subscriber 16-KHz Home-meter at subscriber premises Decadic/ DTMF Telephones PBX Lines (Fixed Head Hunt/ Progressive Head hunt) Call Queuing Facility for subscribers Malicious call tracing with printout of calling line ID. Non-metered subscriber lines Detailed Call Records printout for all calls or long distance calls Service restrictions: All O/G calls barred/ All O/G except level ‘1’ calls barred/ STD calls barred/ Restricted STD calls barred/ ISD calls barred/ Restricted ISD calls barred/ All I/C calls barred/ All calls except Emergency calls barred

Trunk & Routing C-DOT 256P RAX

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Features Routes up to 64: Each route to have 04 trunk groups/ Each trunk group to have 08 circuits Prefixing/ deleting – 0 to 5 digits Routing and charging decisions based on the category of I/C trunk groups and the outgoing route. Trunk Offer facility for Operator calls Flexible trunk protocol to take care of “immediate release”, “CSH time-out”, “Release Guard” etc. All parameters for trunk groups and routes are field programmable. Administration feature

Two levels of password protection for all data User-friendly MMC for: Subscriber data administration/ Trunk and routing administration/ Charging & billing administration/ Traffic administration/ Line, trunk, service circuit testing/ Exchange installation commands

Maintenance feature

Alarm reporting: Fixed alarm number with error prioritization Remote monitoring with tones Status display: Card active, passive, faulty indications/ Terminations free, busy, faulty/blocked Established calls retained on plane switch-over Forced copy change over every 24 hours and on command Automatic System Recovery (ASR) Line and trunk testing on command Trunk testing on command/ periodic thro’ Answering Circuit On-line self diagnostics to run on all controller cards

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Test reports generation for lines, trunks and service circuits Control sanity checked by the usage of: Watch dog cross connections/ Sanity punch messages/ Communication link checking/ System audits and refresh programs Equipment Practice

Cabinet Width: 1045 mm Cabinet Depth: 580 mm Cabinet Height: 1080 mm

Environmental Requirement

Temperature: As per QM 333 Category B2 Relative Humidity: Up to 95%

Grounding

Less than 2 Ohms

Power Supply

-48V +/- 4V Power Plant with battery backup 230V +/- 10%, 50+/- 2 Hz primary source

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C-DOT 256P RAX APPENDIX - B EQUIPMENT SUMMARY PRINTED CIRCUIT BOARDS Sl

Card Name

Code

Part Number

Qty

1

RAX ADMINISTRATION PROCESSOR

RAP

APC-RAP 300/T-S03

2

2

RAX SWITCH CONTROLLER

RSC

APC-RSC 314/T-S01

4

3

RAX ANNOUNCEMENT & TONES

RAT

APC-RAT 316/T-S02

2

4

MF SENDER/RECEIVER, DTMF RECEIVER

RMF

APC-RMF 325/T-S01

2

5

SIGNALLING PROCESSOR CARD

SPC

APC-SPC 001/F-S06

4

6

LINE CIRCUIT CARD

LCC

APC-LCC 037/T-S08

7

COIN COLLECTION BOX WITH 16KHz METERING

CCM

APC-CCM 241/TA00 APC-TWT 065/T-

8

TWO WAY TRUNK CARD

TWT

9

4-WIRE E&M CARD

EMF

APC-EMF 064/T-S02

10 RAX TERMINAL TEST CARD

RTC

APC-RTC 327/T-S02

11 CONFERENCE CARD

CNF

APC-CNF 022/T-S04

12 RAX DIGITAL TRUNK SYNC (30-CHANNEL)

RDS

APC-RDS 322/T-S01

13 RAX DIGITAL TRUNK CAS (30-CHANNEL)

RDC

APC-RDC 302/T-S02

14 RAX DIGITAL TRUNK (10-CHANNEL)

RDT

APC-RDT 851/F-S01

15 POWER SUPPLY UNIT - I

PSU-I APC-PSU 036/T-S09

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95

1

4