Test & Measurement Industry Update: Instrumentation Gets Smarter and Faster

NASA Tech Briefs, Aug 2005

As an electronics-based industry, test and measurement continues to evolve as more powerful computers and more sophisticated computing platforms become available. Whether it is a relatively simple handheld meter, or a custom turnkey system, test instruments - as any electronics-based product - are unavoidably tied to the path of the computer processor.

Test equipment computing platforms are many - PXI, PCI, GPIB, USB, Ethernet, and LXI - each with its own advantages for specific applications and budgets. LXI (LAN Extension for Instruments), for example, is viewed by many as the next evolution of Ethernet, and offers scalability, ease of use, and a Web-enabled interface.

"There is a lot of use of standalone test boxes being done over a network, and I don't see any replacement for that," explained Dr. Michael Lauterbach, director of product management for LeCroy. 'You might as well ask what is going to replace the World Wide Web. Ethernet control will be with us for a long time."

Another advantage of LXI is speed. Rather than simply connecting an instrument to a PC, the higher speeds of Ethernet allow the instrument to create a virtual network and interface with each other at higher data rates, according to Linda Rae, senior vice president and general manager of Keithley Instruments. "We're working on a roadmap for LXI-enabled instrumentation. We have plans in the future for that to be a standard interface or platform for all of our products," she said.

Scott Sampl, vice president of the Electronic Products and Solutions Group at Agilent Technologies, agrees that Ethernet will evolve quickly into LXI, but that many users will choose to combine it with other platforms. "In the short term, people will still have test systems that are mixed. Long-term, most of the systems designed today will probably be LXI or Ethernet. Ethernet is such a well-known computer standard that if you put in place a long-term strategy, Ethernet is pretty secure."

Digalog Systems also focuses their test systems on combined platforms, based on a particular application. "We look at what a customer currently is using for their test, what they want to test, and why they want to test," said Ed Shonkwiler, vice president of sales for Digalog. "We often combine technologies - we'll use a PC-based platform with some PCI cards and include a PXI chassis, and have that interfaced via a connector system."

Not all vendors have hopped on the Ethernet/LXI bandwagon. "Ethernet is not and has never been a platform of choice in instrumentation," said Loofie Gutterman, president of Geotest-Marvin Test Systems. "Ethernet is just now emerging as a platform. The purpose behind LXI, which is a great idea, is to come up with a standard for instrument control. Ethernet has a much better throughput and is easy to implement."

Tim Dehne, senior vice president of research and development for National Instruments (NI), agrees that while Ethernet will be used for instrumentation, it has not been the platform of choice. "We see the world as segmenting out and not having a single platform of choice. It's a hybrid world and each platform plays a role."

While IOtech successfully implemented Ethernet about five years ago, LXI and Ethernet do not solve all instrumentation problems, according to Tom DeSantis, IOtech's president. "I don't see Ethernet owning the world of instrumentation in the long run. I see it sharing some of it with USB, based on the type of product. We see that there are almost two camps. There are customers who need to coordinate and mix different types of instruments into a system, and there are engineers who just have a scope on their desk. We see that market inclined to use USB," he said.

"In the case of LXI," DeSantis continued, "we think there's a very nice opportunity for hundreds of companies to contribute their part. LXI is starting off with the philosophy of being a true open standard, so it has the chance of being a multi-billion-dollar market."

The platform of choice in test and measurement is just that - a matter of choice based on factors such as cost, application, speed, and ease of use. "Test is an evolution, just like technology in general," said Shonkwiler. "We've seen things move from GPIB standard instruments in the 1970s to today's PXI and PCI. We'll continue to see that evolve, and it's going to be driven by cost and availability of resources," he added.

Transforming Test With Software

In test and measurement, software has become the means by which users connect, customize, and create instruments. And the ubiquitous nature of Microsoft Windows® has also had a dramatic effect on how engineers make measurements.

"Software is really the enabling tool that gives the power to the end user to create their own systems and instruments," said NI's Dehne. National Instruments' LabVIEW graphical programming software enables customers to create "virtual instruments," including FPGA-based instrumentation. Added Dehne, "With a high-level software tool, we can open that up so that all engineers and scientists can create hardware through a software tool."