CompactPCI (PICMG 2.0) is a well-established parallel bus standard for building cost-effective modular industrial computers. It is supported by a large group of suppliers covering a wide range of products: from components to complete systems. CompactPCI is based on the Eurocard form factors 3U and 6U, and supports 19" mechanics. It is reliable, robust and maintenance-friendly. A passive backplane with PCI up to 64Bit/66MHz connects a system slot (CPU) to up to 7 peripheral slots (devices) – or more with bridges.

Additions to the core specification guarantee that the more demanding industrial requirements like hot swap, multi-computing, rear I/O of mezzanine cards or conduction cooling can be solved in a standard way.

Nowadays parallel PCI bus technology is complemented by fast serial point-to-point connections. Interfaces like SATA/SAS, USB, Ethernet or PCI Express coexist in a modern computer. These serial interfaces are all available directly at the chipset. Thus, the structure of a computer slowly changes from a bus-based system to a system with a star topology.

Within a CompactPCI system the serial point-to-point connections are realized in a proprietary way via user-defined pins on the J2 connector. Unfortunately, this leads to a growing incompatibility of assemblies from different manufacturers. Therefore, two new PICMG standards – CompactPCI PlusIO (PICMG 2.30) and CompactPCI Serial (PICMG CPCI-S.0) – define the common integration of serial high-speed signals into a modular 19” environment.