CompactPCI is a modular 3U (or 6U) Eurocard based passive backplane system used for high integrity control and communication systems. The system architecture offers a 32 or 64 bit data bus for very high performance systems. CompactPCi is maintained by the PICMG (PCI Industrial Computers Manufacturers Group) Consortium along with a number of ruggedized bus and inter-board module standards. CompactPCI cards are designed for fast and easy change over within standard racks – they can also include hot-swap functionality. The combination of metal front panels and positive retention makes them suitable for high shock and vibration applications in defense and industrial equipment as well as high availability communication systems.