Trends in automated test
Bob Stasonis, Director Marketing Pickering Interfaces discusses trends in automated test and finds modular platforms desirable
1. Discuss the trends in automated test?
From my perspective, automated test today is highly modular in nature. While there are some areas of test that require large stand-alone instrumentation (Millimeter Wave Technology applications come to mind), that barrier for modular test is dropping. For example, when PXI first started, a few MHz was the best you could expect to measure – now 50 GHz is achievable.
Modular platforms are desirable for many reasons – small footprint, common chassis for many instrument types, tightly coupled triggering schemes, and cost. While there are still some automated applications that are essentially “do it yourself”, they are getting few and far between.
The test industry of course has to deal with increased RF Bandwidth, complex waveform capture and generation, as well as increased functionality of each UUT (Unit Under Test). But the industry also has to deal with the reduced individual value of each UUT tested. By that I mean, how much can we afford to test? For one example, look at the cellphone industry – their cost of test is probably half of what it was 5 years ago, yet the complexity had gone up exponentially. If one were to look at the test strategy of a smart phone, I would believe that the most complex testing is in the lab and NPI (New Product Introduction). In volume production, it can be as simple as “Does the device turn on? Then ship it!”
- What are the challenges of automated test industry? For the most part, the challenges in automated test are the same as in the past – the balancing act between budgets, test times, specifications, accuracy, and first pass yield. What is changing depends on the application – bandwidth, complex modulation schemes, and high speed serial busses do present problems for the test engineer. But generally speaking, as I mentioned in an earlier answer, a bigger issue may be that many products have such a low build cost that there is very little rework budgeted for. If it fails, bin it. Or do we test at all because we can’t afford the added expense? The trend in low cost electronics is to get the manufacturing process right as soon as possible and minimize potential failures.
- Discuss the modular platform for automated test? There are several modular platforms for automated test. At present PXI is king. VXI, which has been around since the late 1980’s is now primarily for legacy applications. While there are a few new modules introduced by VXI manufacturers, they are not addressing the newer manufacturing challenges.In addition to PXI, a newer modular platform called AXIe is starting to get attention. AXIe has the same PCIe fabric and programming as PXI, but with multiple configurations for minimal rack space as well as substantial PCB Real estate and greater power densities compared to PXI for large, complex applications. So far, most AXIe applications I have seen are related to Semiconductor test - also there are very few AXIe products at this time. But there are more than ten companies who are members and in terms of percentage, AXIe is showing the greatest growth in the Test market. So I would not be surprised to see more AXIe in the future.
- Why PXI is the appropriate platform? The PXI Platform is ideal for so many applications for many reasons. The first is market recognition – ask any test engineer about modular test and chances are they will say “PXI”. Second is choice – there are literally thousands of PXI Modules available from over 50 companies. Finally, there is the “play nice” strategy of PXI Manufacturers. As it is still a Hybrid world – In other words, there are still instruments and power supplies that will not fit efficiently in a PXI chassis – PXI software drivers work well in a test system environment that supports PXI, PXIe, LXI, GPIB, and even PCI modules.
5. New capabilities of PXI test system. PXI has evolved to meet the speed and complexity of so many applications. The latest generation of PXIe features us to 8 GB/s data rates per module for very complex waveform generation and acquisition. Members of the PXI Systems Alliance have expanded the bandwidth of PXI instruments to measure up to 50 GHz. The fact that PXI Express chassis support legacy non PXIe modules in hybrid slots means that no instrument or switching is obsolete. PXI is able to support legacy applications as well as new ones, often in the same chassis.
- Your PXI Test solutions. Since 1998, Pickering Interfaces had been very focused on signal switching and sensor emulation. We have been involved in PXI almost since the beginning or PXI. In the past 18 years, we have designed and built a catalog of over 1,000 PXI Modules. We offer a breadth of choices ranging from DC to fiber optic switching, including the highest density matrices on the market, the highest switching voltage (1,000 V) available in PXI, Microwave switching up to 65 GHZ, and the broadest range of modules for simulating resistive sensors, RTD probes, and strain gauges. With a 3 year warranty and offices and agents around the world, we have the products and the support to serve our customer’s needs.