Automated EMC Testing to Make Your Job Easier

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Overview:
In recent years, there has been a shift in the process of performing electromagnetic interference (EMI) and electromagnetic compatibility (EMC) testing from a manual approach to a software-driven, automated approach. Generally speaking, this automation has provided numerous benefits to both those responsible for performing testing, as well as for those whose product is under test. This discussion will provide an overview of traditional testing methods and the pros and cons of implementing automation and control software. Considerations for software selection will also be discussed. Lastly, predictions on the future direction of EMC test software will be made.

Who Should Attend?
EMC systems and test engineers, test technicians, lab engineers, lab managers

Flynn LawrenceSpeaker: Flynn Lawrence
Flynn Lawrence is an Applications Engineer for AR RF/Microwave Instrumentation.  At AR, Flynn is actively engaged in new application and product development and testing, worldwide sales and customer support, as well as hardware demonstrations and training.  Prior to joining AR, Flynn was an EMC Systems and Test engineer, working in requirements maintenance, test planning and test execution on military space components and systems.

The following are questions presented to the speaker by the attendees during the webinar, along with answers to each.

Do you have any recommendations for automated software for DO-160 and MIL-STD-461 testing?
Answer: AR’s emcware provides automated test routines for both DO-160 and MIL-STD-461. For both standards, emcware covers several versions of each standard (past and present).

Flynn had mentioned that hardware was now coming with more and more automation software within it. Would you say that this is going to be a must-have in the next few years or will it be awhile before it becomes more than simply a nice feature?
Answer: ‘Must-have’ may be a bit strong, but I have certainly seen a trend towards automation software being ‘expected’. Companies and test houses are constantly looking for ways to streamline their testing processes and automation software is almost always the solution that makes the most sense.

How is uncertainty information managed in automated setups? This is regarding the setup and the addition of EUT monitoring devices. How is this automation accounted for?
Answer: Automation software can store and recall correction factors for various pieces of measurement equipment and passive components, but I think that uncertainty is too difficult to account for in software. I suppose that uncertainty could be reported by software based on what is reported by calibration certifications, but I’m not sure how you would actually apply uncertainty to recorded measurements. Do you simply add up the uncertainties of all equipment in the measurement chain? Do you try to compensate for each uncertainty? Compensate for overall uncertainty?

I did my RE measurements for 3 days. Is it possible to do it in one day?
Answer: It’s hard to put a finite number on the magnitude of time savings, but adding automation software into the mix will certainly provide significant time reduction. First, equipment information, including calibration factors, can be pre-loaded and saved into the software prior to testing and automatically applied during testing to eliminate the tedious task of manually entering antenna factors into a receiver. Next, pre-defined test setups can be used instead of manually entering scan parameters into a receiver. Once data is gathered, the automation software can automatically compare the data to a single or multiple limit lines and quickly determine out of spec conditions. Lastly, report generation through the automation software can save an enormous amount of time from having to manage all of the data and write a report manually.

Which part of the ESD measurements can not be automatized?
Answer: ESD test locations are very difficult to automate. In order to do so, some kind of mechanical apparatus would have to be constructed in order to place the ESD gun in the exact location and it would need to be redundant testing of the same type of product. Otherwise, you’d be developing a new location automation routine for every product.

I use spectrum analyzer with floppy with windows 2000
Answer: As an example, AR’s emcware supports HP 85XX and Agilent E740Xa spectrum analyzers. emcware also provides driver templates for the user to develop their own drivers and AR can provide custom drivers.

Most of the equipment run with GPIB. Will this change to Ethernet?
Additionally, but just a comment – I am using TILE (ETS Lindgren) and I am very happy. It is very flexible, but still very useful to automate.

Answer: It is our understanding that labs are moving to Ethernet, for obvious reasons, such as having the ability to control equipment through a LAN. Many of today’s software packages offer this option.

The test lab I go to argues automated testing is too time consuming vs. manual for immunity testing. I see their point, but it appears accuracy is reduced. How would you address this concern?
Answer: I’ve heard this exact same argument at an accredited test facility myself. I think there are a couple factors that could lead to this.

  1. The primary issue is probably the NRE to get the lab prepped for running automated routines. Some software packages are complicated to set up, but also there’s no such thing as non-zero effort. In many cases, labs believe they are just too busy to spend the time tinkering with software. But, again when you compare the efforts automated versus manual, the automated approach wins in almost all cases.
  2. Another issue is equipment. I’ve been in quite a few labs where equipment is juggled back and forth from different test areas and none of it is dedicated to a single test location. Also, some labs are still running off ancient equipment that a lot (or all) software packages don’t (or won’t) support. In these situations, it can be a great advantage to have a software package incorporated throughout the lab so that these different pieces of equipment can be seamlessly integrated into different test areas.
  3. In many cases software helps a great deal to speed up pretest verification, by using the same parameters each time the test is performed. If setup properly the software will take that data and allow the user to observe performance trends that would take considerably more time if performed manually.

What about video monitoring?
Answer: Several camera manufacturers offer this capability. As cameras with anomaly detection become more prevalent, I believe that this capability will certainly be added to automation software packages.

What are the popular software now? Any suggestions?
Answer: AR’s emcware offers over 500 pre-defined automation routines for Radiated Immunity (RI), Conducted Immunity (CI), Radiated Emissions (RE) and Conducted Emissions (CE) with an extensive list of equipment drivers and an Equipment List function to easily maintain and manage all of the equipment in your laboratory. Emcware offers flexibility without complexity and is available for free download at www.arworld.us.