CPCI

CompactPCI (CPCI) is an industrial and embedded computing standard that uses the PCI bus as its electrical backbone. Defined by the PCI Industrial Computer Manufacturers Group (PICMG), CPCI aims to provide modular, rugged, and scalable hardware for telecom, industrial automation, aerospace, and defense applications.

The physical form factors are based on the Eurocard standard, with 3U and 6U cards that plug into a backplane. The backplane carries the PCI data and control signals, power, and system-management lines, enabling high-density, modular systems. Traditional CompactPCI backplanes typically support a 32-bit PCI bus at standard speeds, commonly 33 or 66 MHz, with later extensions introducing higher bandwidth options and, in some variants, 64-bit data paths.

CompactPCI boards are designed for hot-swapping in many implementations, allowing maintenance or upgrades without powering down the entire system. The standard emphasizes mechanical interoperability and electrical compatibility, while leaving enclosure design, cooling, and system-specific features to individual vendors.

Applications for CompactPCI include telecom switching equipment, industrial controllers, process automation, test and measurement gear, and military or aerospace systems. As computing needs evolved, the ecosystem expanded to include CompactPCI Serial (CPCI-S), which emphasizes high-speed serial interfaces and PCI Express, Ethernet, and other modern I/O while retaining the compact Eurocard form factor for certain use cases.

The CPCI ecosystem is maintained by PICMG, which publishes specifications and compliance requirements for CPCI and its derivatives, supporting interoperability across vendors and products.