Switching in test and measurement enhances automation and efficiency in prototyping next-generation wireless communications: an interview with Bob Stasonis, vice president of Pickering Interfaces Inc. in Chelmsford, Mass.
Question: What is switching in high-performance test systems, and why is that important?
Answer: Switching in high performance test systems is as important it is for any test system. Switching allows for the sharing of test resources, automating test by connecting to test points programmatically, and improving repeatability and accuracy by minimizing human interaction with the DUT (device under test). In the case of high performance test systems, we find that the switching required will be more accurate than a lower performance test system and in some cases, faster to connect instruments to test points.
Question: What is the role of test systems switching in prototyping next-generation wireless communications systems?
Answer: It depends on where in the product development life cycle you are at. Our experience is that switching is used primarily for environmental test systems and HILS (hardware in the loop simulation). In the case of the environmental test, switching is used to monitor the performance of multiple DUTs in a chamber over long periods of time. For HILS applications, switching is used to introduce faults into the test. This could be faults like an open circuit, short to Ground or Power, and even faulty data. The idea is to see how the DUT and it's firmware react to a fault. The example I like to use relates to a Jet fighter. If an altitude sensor for the engine fails, the FADEC (full authority digital electronic controller) for the Jet engine must "limp along" and get the plane back to base. The pilot can't pull up to the side of a cloud and call AAA!
Question: What are the most important design considerations in prototyping next-generation wireless communications for military applications, and how does that compare and contrast to prototyping commercial wireless systems?
Answer: From my perception, there is not a lot of difference between the two, at least from an electronic test standpoint. Both industries are testing for signal integrity and the handling of potentially multiple modulation schemes and protocols - perhaps because of the downward price pressure in commercial applications, this portion of the industry usually will test less and relay on "plug and pray" because they are squeezed on the cost of test. The military cannot be so relaxed about test as they need every system to be operational immediately and for the long run. The difference that we see is usually related to environmental issues. Temperature, vibration, and G forces are far more demanding in military applications.
Question: What are the most important enabling technologies involved with prototyping next-generation wireless communications systems using switching in test systems?
Answer: Clearly, the answer here is related to enabling technologies is in the areas of modular test. The military's demand for rugged, portable test systems, that are directly related to test systems used in design and manufacturing allows for the sharing of test code, speeding the time to deployment. Modular test companies especially in the PXI and PXI Express product families are pushing the envelope in terms of size, bandwidth, and feature sets to meet the military requirements worldwide.
Question: How do you see design issues and enabling technologies related to test systems for prototyping wireless communications systems evolving over the next five to ten years.
Answer: Our product roadmaps are driven by the products to be tested. So design issues are better addressed by cooperation between military branches and the commercial test industry. From there, we can design and implement what is needed to test the next generation defense systems. Our company has a very "Agile" design team. In the past, we have been able to design new switching in a few months to address new requirements.
