Replacing the DMM instrument in legacy ATE applications

A common problem facing all owners of automatic test equipment (ATE) is the obsolescence of instrumentation. That is, as the ATE progresses through its life cycle, the instrumentation within eventually becomes obsolete and is no longer maintainable. In many cases, this original instrumentation is "kept alive" for 20 years or longer. However, we must face the reality that the ATE instrumentation will eventually need to be upgraded with a functionally equivalent version that is currently available in today\´s marketplace. This "functional equivalence" between the old and new digital multi meters (DMM\´s) and potential approaches to dealing with these differences is the primary subject of this paper.