VXIbus: a modern alternative for instrumentation.

VMEbus extensions for instrumentation (VXIbus) is currently in its fourth revision (1.4) and being adopted as an IEEE standard. VXIbus instruments are now available from a variety of manufacturers and are following the pattern established by the familiar IEEE 488.1/.2 interface standard. The difference is that "instruments on a card" with a wide range of performance are available within a common standard. Users can choose from low cost A- and B-size cards, moderate price and performance C-size cards, up to high performance, high cost D-size cards. Instruments can be relatively simple, register-based cards or more complex, message-based cards with local intelligence. The fundamental basis for VXIbus is the VMEbus standard. VXIbus adds additional power supplies, local buses, triggers, and other features to support collections of instruments organized in a 13-slot backplane. This paper briefly introduces VXIbus, highlighting some of its major architectural features. Other papers in this session illustrate a number of considerations that range from application-oriented to instrument development concepts.