PXIcompactPCI

PXICompactPCI is a modular instrumentation standard that combines the CompactPCI backplane with the PCI-based PXI (PCI eXtensions for Instrumentation) specification to support chassis-based measurement and control systems. It leverages the CompactPCI 3U and 6U Eurocard form factors for cards and backplanes and uses the PCI bus as the data path, while PXI adds system timing, triggering, and common resource management to coordinate multiple modules.

The standard is developed and maintained by the PXI System Alliance (PXISA), an ecosystem of vendors working with PICMG and other industry bodies. PXICompactPCI implementations aim to be compatible with PCI-based instrumentation while incorporating PXI features such as a dedicated trigger bus and synchronized timing across modules, enabling coordinated operation of multiple cards in a chassis.

Backplanes in PXICompactPCI provide a PCI bus to each slot, a timing and triggering interface, and the mechanical and electrical interfaces required for modular cards. Card sizes are 3U or 6U, and chassis are designed to house multiple slots for data acquisition, signal conditioning, and instrument control cards. Hot-swapping capabilities are supported in many PXI systems, depending on the chassis and backplane design.

Applications for PXICompactPCI include automated test equipment, data acquisition, industrial control, and scientific instrumentation. The PXI approach emphasizes modularity, reconfigurability, and repeatable timing, enabling scalable test systems and laboratory setups. PXI has evolved with PXI Express, which uses PCI Express while preserving PXI software and system management concepts; classic PXI/CompactPCI implementations remain common in legacy installations and cost-conscious environments.