Technology - who can keep up? New applications are announced daily, and many more already in our cars, PCs, appliances, and home theaters that did not exist a short time ago. Every year, products and systems with more intelligence and convenience are available, usually at a lower cost than previous models. The basic premise of our market driven economy is the need to create new products that people will purchase – essentially, technology drives the economy. And don't we all like new technology!
But just as technology progresses, test technologies and their implementation strategies must change as well. Today's test requirements include factors such as increased simulation of sensors, fault insertion, higher data rates, and increased precision. All of these factors must be accomplished while simultaneously increasing test throughput and lowering costs. While these electronic test strategies have always been a tough challenge for our industry, it seems to be a more daunting prospect to support today’s technology.
Fortunately, the Test and Measurement industry has been developing new solutions to address these needs. In many cases, the solution has been the PXI (PCI eXtensions for Instrumentation) modular instrumentation architecture, which has shown itself to be a remarkably flexible platform. Over the last 17 years, the sixty plus members of the PXI Systems Alliance (PXISA) have continued to innovate and create modules that can address the newest technologies. Unique test and measurement solutions are being developed in PXI that are not available in other test platforms.
Why is PXI Successful?
- Choices in Software – Many programming languages, including Real Time Operating Systems, as well as focused software for applications like HILS (Hardware In the Loop Simulation) make implementing PXI easier.
- Connectivity – The best hardware is useless unless you can connect it to the UUT (Unit Under Test). Fortunately, there are vendors who have created mass interconnects that work well with PXI.
- Vendor Creativity – The small size of 3U was seen as a detriment back in 1997 when the PXI specification was released. It was felt that the small size, especially when compared to VXI, would limit the bandwidth and density that could be achieved. Fortunately, the naysayers were wrong! Switching densities of 4,000 to 8,000 relays in a single matrix, 1,000 volt isolation, and RF instrumentation of up to 26 GHz and greater are just a few examples of what is possible in PXI.
- Ability to work with other test platforms – In many instances, hybrid test systems are the norm. This can be for reasons like—availability of test and measurement equipment, test budgets forcing hardware re-use, and partial re-hosting/upgrades of existing test systems. PXI has been shown to work well in these environments.
- System Integrators – This segment of the test industry has embraced the PXI platform as a solution for many applications. Their ability to make PXI work is a big part of the success.
But enough talk on the “Why” – let’s focus on the “How”
Because we cannot adequately present applications on every PXI advantage above in the limited space we have, we are going to focus on those applications where specialized simulation of a particular portion of a UUT’s operating environment is necessary for test that could be simulated using PXI. Granted, every test system is a simulator as the system replicates the car, PC, or missile the UUT will ultimately end up being part of. But new applications require new simulation techniques, which is what we want to showcase here.
Below you will find links to several application case studies where PXI was an important part of the required electronic test strategy and in some cases made the efforts easier. Some of these applications are unique enough that our readers may not normally think they would require advanced testing techniques, much less any simulation. But in each case, PXI was a major portion of the electronic test strategy.
- Automotive ECU Fault Insertion - In this case, PXI provides an open platform for HILS requirements. Combining this with the large range of hardware available from Pickering Interfaces and many other vendors, enables the most flexible and cost-effective alternatives to proprietary systems. The modularity and openness of PXI enabled the integrator to design a highly scalable solution with plenty of potential for evolution. Read entire story here >>
- Satellite Payload Testing - In this case, when specifying hardware for this simulation requirement, a decision was made by the customer not to base it on heritage tools and strategies. Instead, it was decided to take a fresh look at what was available and what was possible, with the goal of choosing an optimally engineered solution within a defined budget.
The decision was made to base the hardware primarily upon the PXI standard, with Pickering Interfaces as one of the main suppliers. The reasoning behind this decision came down to one statement from the customer: “The solution fitted our requirement, as opposed to our requirement having to fit the solution”. Ultimately, PXI had the right products at the right price. Read entire story here >>
- Diesel Engine Temperature Simulation - In this case, with various measurement and stimulus modules already available in PXI and a requirement to support RTOS software, PXI was seen as the natural choice of platform for new product design here. The solution developed was a 3U PXI module (model 40-262) that supports either six channels of RTD simulation (in one slot) or 18 channels (in two slots). Read the entire story here >>
- Find additional application studies using PXI here >>
From the applications listed above, it’s clear that PXI products can simulate the signals necessary for a variety of applications, including Consumer, Transportation, and Aerospace. PXI can achieve the densities required to make the system manageable on the test floor, accurate enough to meet customer demands and support specialized environments like RTOS. And, of course, these three examples are simply from Pickering Interfaces’ perspective. Many other test and measurement applications, including others for simulation are being developed by other PXISA members and System Integrators. The key premise you can take from this article is that PXI can very likely address your test requirements – real or simulated.
Pickering offers over 1,000 PXI modules
- DC power supplies
- Digital I/O
- Signal conditioning (amplifiers and attenuators)
- Signal generation
We also offer our eBIRST Switching System Test Tools - tools to help lower the cost of switching system ownership. As well as our Switch Path Manager signal routing software which simplifies signal routing through switching systems and speeds up the development of switching system software. No other switching vendor offers this level of support for their products.
Have questions about PXI or any of our switching products? Please feel free to contact one of our switching experts today.
About the authors
Shaun Fuller is the East Asian Business Development Manager for Pickering Interfaces. Shaun is based at the company headquarters in Clacton-on-Sea, England. Over the last 25 years, he has held engineering & product management positions within the company. E-mail: firstname.lastname@example.org
Bob Stasonis is the Americas/Asia Sales & Marketing Director for Pickering Interfaces. Bob is based in the US Northeast headquarters in Chelmsford, MA. Bob has written numerous papers and articles on the subject of Electronics Test. Over the last 35 years, Bob has held Technical, Sales, and Marketing positions with Pickering Interfaces, Teradyne, GenRad, and Schlumberger. Bob is on the Board of Directors and past President of the PXI Systems Alliance, a Board Member of the LXI Consortium, and a former VP for the American Society of Test Engineers. E-mail: email@example.com