Measurement in IEEE 1641 and its application in a CASS TSF Library

A new revision of IEEE Std 1641 has been completed and should be available before the end of the year. This standard, which provides a method of accurately defining signals and tests, has been further developed with many new improvements. The standard provides for libraries of pre-defined signals which may be re-used within a technology or project. There have been many examples of stimulus signals, both as stand-alone signals and in libraries, but fewer examples of measurement models. An exercise has recently been completed to provide a sample measurement library for the CASS system. This has resulted in a library containing many examples of measurement Test Signal Frameworks (TSFs). This paper explains the two main types of measurement that may be described using IEEE 1641 and provides examples of each. This is supported by examples of TSFs for several of the measurement facilities provided in the CASS system. Test Programs for this system are defined using a subset of ATLAS, so the measurement TSFs in the library relate directly to the ATLAS nouns and noun modifiers used by the system. These examples, illustrated with simulations of the measurements described, further clarify the difference between intrinsic and generic measurements in IEEE 1641 and how they relate to real measurement facilities.