Modular architectures are used to try to make scalable, high‐speed, and/or high‐power applications a reality. VXI 4.0 adds power, speed, and standards‐compatibility capabilities that will enable the next generation of test system integrators to solve some of the major hurdles that have limited modular architectures in the past.
EADS North America Test and Services
VXI technology tutorial includes:
• VXI technology basics
• VXI chassis
VXI or VXIbus is a powerful test instrumentation technology that is based on the VME bus. Indeed the letters VXI stand for VME eXtension for Instrumentation. Its development was born out of the need to be able to produce smaller yet effective solutions for test systems. At the time of its development GPIB controlled equipment was the main way in which automatic test equipment systems were built up to provide functional test solutions. While these were effective they were relatively slow and occupied considerable amounts of space because each item of test equipment was contained in its own case.
Choosing the right platform (or combination of platforms) for your ATE system can save you money and labor—plus improve measurement results. You can assemble an instrumentation system in several different ways. One option is to "rack and stack" standalone boxes and connect them to a computer via the well known General Purpose Interface Bus (GPIB), also called the IEEE-488 bus. This makes it simple to swap out instruments and create new configurations quickly and easily.
Another route is to use instruments on VME eXtensions for Instrumentation (VXI) and PCI eXtensions for Instrumentation (PXI) cards that plug into a backplane. Such a solution seems ideal, with the computer and the instruments it controls all in the same card cage. However, not all instruments are availlable as plug-in cards.
Experience has shown that it's seldom possible to put together a complete system using all bus-based or all standalone instruments. Generally, there will be some of both.
This article reviews each of the platforms in detail, discussing their benefits and limitations. It also gets into the mixing and matching of the buses for an optimal solution.