Virtual Instrumentation

Is virtual instrumentation an option or need? By Ian Bell Technical Marketing Manager National Instruments Corp.

Never has the need for test been greater. As the pace of innovation and customer expectations have increased, so has the pressure to get new, differentiated products to market quickly. In the consumer electronics market, for example, there is a drive to integrate greater functionality into ever smaller devices while lowering costs. The economic downturn of the past years has not reduced the need to innovate, but has added the restraint of fewer resources. Not only does the successful manufacturer have to test more functionality on a higher volume of units in shorter time, but it also needs to build test systems faster, operate them with fewer staff and take up less space on the manufacturing floor. All these conditions drive new requirements for validation, verification and manufacturing test. A test platform that can keep pace with this innovation is not optional—it is essential. The platform must include rapid test development tools

that are adaptable enough to be used throughout the product development flow. The need to get products to volume quickly and manufacture them efficiently requires high-throughput test. To test the complex multifunction products that consumers demand requires precise, synchronized measurement capabilities. As you incorporate new applications to differentiate your products, your test system must quickly adapt to test the new features. Virtual instrumentation uses mainstream computer technologies combined with flexible software and modular, high-performance hardware to create powerful, computerbased test solutions. Using this approach, engineers and scientists can capitalize on the everincreasing performance of PCs and take advantage of the freedom to define measurement and automation solutions that meet their specific needs. Virtual instrumentation tools build on standard commercial technologies such as PC components and the Internet. As these commercial tech-

nologies rapidly evolve, they improve in performance while reducing costs to ser ve the mass market. National Instruments’ LabView graphical development software uses the latest Windows, Mac OS, Linux and other operating systems to deliver multithreading execution combined with graphical ease of use. NI measurement hardware takes advantage of the power of PCI and PXI computer buses to transfer data at high speeds into memory. Virtual instrumentation incorporates three essential technologies: • Intuitive software tools for rapid test development; • Fast, precise and modular I/O based on commercial technologies; • A PC-based platform with integrated synchronization for high accuracy and throughput. As automation has increasingly become a requirement in testing complex products rapidly, software has become an essential element in all test systems—from design verification through to highly-automated

Figure 1: Whether acquiring a single channel over a short period of time or thousands of channels over many days, virtual instrumentation uses the same platform of hardware and software to accomplish both tasks.

manufacturing test. To quickly deliver test systems that can adapt to testing new functionality requires an integrated set of test development tools. These tools include test management, test development and I/O drivers. The second essential technology for test is modular I/O, including technologies such as modular instrumentation and data acquisition. Modular I/O uses commercial chip technologies to create virtual instruments with high performance and low cost. The rapid development of widely used commercial technologies such as ADCs, DACs, FPGAs and DSPs has resulted in the rapid growth of modular I/O functionality and performance. In many cases, the accuracy of virtual instrumentation exceeds that of traditional instruments. PC-based test platform Today, all modern test systems include a computer. The PC has become an essential integrating platform at the center of the test system and not just peripheral to it. The gigahertz processors, high-speed buses, wide availability of software, constantly increasing performance and low price make the PC a suitable test platform. Consider the performance advances that the PC has undergone in the past 20 years. The only other element of test systems that has undergone a performance increase of this magnitude is perhaps the device under test itself. By combining powerful, flexible software with modular instrumentation hardware, engineers can create customized instruments that meet their application needs. The proprietary, fixed functionality inherent in traditional instruments is no longer a limiting factor in providing robust test solutions. Using virtual instrumentation, test engineers can define the exact characteristics for their automated acquisition, analysis and reporting without worrying about the incompatibilities that may exist among different

pieces of hardware and software from different vendors. This significant productivity gain is possible because of the tight coupling between software and hardware. Whether engineers

are acquiring a single channel over a short period of time or thousands of channels over many days, virtual instrumentation uses the same platform of hardware and software to ac-

Figure 2: LabView graphical development software uses the latest Windows, Mac OS, Linux and other OSes to do multithreading.

complish both tasks. Hence, virtual instrumentation tools accelerate product development by providing a set of common tools for efficiently reusing test code throughout the process. Engineers can detect errors much earlier by taking measurements during each stage of development. This leads to more efficiency and higher quality from design to manufacturing. The advantages of virtual instrumentation are being realized in thousands of automated test applications today. Being able to re-create a complete rack of instruments in less space with less programming is an advantage. With the introduction of the NI 200MSps mixed-signal suite, along with the integration of Express technology, engineers can easily perform a large number of measurements and test functions at reduced cost.

Virtual instrumentation has embraced the PC and PC-based technologies to deliver performance advances in test applications. Thousands of companies have successfully deployed virtual instrumentation into their design labs and manufacturing floors. Virtual instrumentation and automation solutions easily adapt to changing needs in a continuously shifting marketplace. The reach of virtual instrumentation has already begun to expand into areas such as system design, embedded systems and control. In the next few years, we will encounter essential elements of virtual instrumentation such as powerful and flexible software, modular hardware and PC-based technologies, shorter development time, and increased performance in test, product development and manufacturing.