What is a test instrument? For many decades, this was a relatively straightforward question to answer in terms of size, appearance, and functionality. However, the definition and types of instruments are going through a rapid evolution these days—so much so that vendors are increasingly providing tutorial resources to help explain the new types of instrumentation and their role in the testing process. Unsurprisingly, this evolution in instrumentation follows the dramatic change in business and technical requirements for test and measurement throughout the design flow and across a multitude of global industries.
The transformation in the instrumentation landscape also represents substantial investments that have been made over the past decade to dramatically improve instrumentation for design and test. On the benchtop, efforts have been put into keeping up with extreme sample rates and frequencies and emerging wireless standards. In automated test, unprecedented R&D investments have gone into defining an entirely new class of optimized instrumentation known as modular instruments.
Modular Instruments Step Up
The impact of modular instrumentation, such as PXI, on test engineers and their companies is revolutionary in terms of lowering test times, improving accuracy, increasing flexibility, and enabling major reductions in size and cost. And the benefits aren’t limited to one particular application or industry. There’s a wide range of applications for which PXI modular instrumentation is proving to be a viable and preferred solution.
As a result, I’ve been asked many times what’s enabling PXI modular instrumentation to make such a significant impact in automated test beyond the compact size and smaller footprint. The short answer is software and Moore’s Law. Similar to the latest tablet PCs, smart phones, smart vehicles, and other intelligent devices, software has become the key ingredient to enabling these devices to leverage Moore’s Law to the fullest.
In reality, software abstracts the complexity of these devices and makes all underlining components such as wireless ICs, touchscreen interfaces, and the latest embedded processors work together as a unified system. Often a consumer’s interaction with these devices is only through software.
The same is true for PXI modular instrumentation in automated test: software is the instrument. Engineers can use system-level software to take full advantage of an entirely new breed of high-performance yet flexible PXI modular instruments, while making it function as a system. Multicore computing, FPGA embedded processing, and timing and synchronization are three essential technologies harnessed by the software-defined nature of PXI modular instrumentation.
For instance, using a PXI-based modular instrumentation system with NI LabVIEW, a test engineer can quickly design a high-performance test system that utilizes the latest multicore processors and user-programmable FPGAs. This same system can synchronize all of the measurements with intuitive software-defined timing and synchronization across the backplane at industry-leading levels of timing accuracy. The resulting productivity and performance are unsurpassed in comparison to the other methods commonly used in industry today.
Software Behind The Wheel
So how is software driving this improvement in productivity and performance in PXI modular instrumentation for automated test? First, it involves leveraging the latest commercial off-the-shelf (COTS) technologies driven by Moore’s Law in a compact, modular instrumentation form factor. Second, it entails using software that’s optimized for measurement and control applications to unlock the core benefits of COTS technologies without requiring expert knowledge in all of the advanced capabilities.
One example is the inherent enabling of multicore performance in software within the parallel data flow of test application software, such as NI LabVIEW. This contrasts sharply with the low-level C-based approach to using multicore processing, which adds significant development time and software maintenance costs for advanced multithreaded programming.
Another example is the ability to program Xilinx FPGA targets on PXI reconfigurable I/O modules using a graphical software development tool as opposed to learning low-level hardware description languages (HDLs). This allows for rapid development of proof-of-concepts and deployable solutions with fewer software and hardware development personnel. It also drives a much lower total cost of ownership from a development, deployment, and operational perspective.
Finally, graphical data flow software languages for measurement and automation, such as NI LabVIEW, provide hardware-timed loops and advanced timing capabilities based on deterministic hardware timing versus typical OS-based (operating system) software timing. This level of timing and synchronization ability would otherwise require significant software and hardware customization within traditional systems.
However, using software-defined PXI modular instruments with NI LabVIEW, these advanced details can easily be abstracted. Test engineers then can avoid getting bogged down in the complexity of their tools and instead focus on delivering a working system faster and at a lower overall cost.
In essence, these are some of the many reasons why PXI modular instrumentation is making such an impact for test engineers and today’s leading electronics companies. Given the influence of Moore’s Law and the explosion of new components being driven by the Internet generation of smart devices, it’s clear to see how software-defined modular instruments will continue to have a greater influence on test systems through the design cycle and across many industries.
Moving forward, the growing complexity of hardware designs and devices under test will place even more emphasis on the role of software in next-generation instrumentation. It is quite likely that software-defined, system-level abstraction of technologies in future automated test systems will become a requirement as opposed to a competitive advantage today. Hence, it’s easy to see why software has truly become the heart of today’s highest-performance PXI modular instrumentation.