VME, VPX, and VXI Controllers and Processors Information
VME, VPX and VXI Controllers and Processors Information
VME, VPX and VXI controllers and processors manage data transfers between devices in VME, VPX, and VXI systems. They control the status of interrupts, interrupt requests (IRQ), registers, and triggers, as well as network instruments for testing and analysis. There are several types of VME, VPX and VXI controllers and processors. PC controllers or remote controllers use a personal computer (PC) to control and manage VME, VPX, and VXI systems. Embedded controllers are packaged to fit in a VME, VPX, or VXI chassis, permitting access to system devices and resources without the need for an external command module. Real-time controllers are also embedded, but a use a real-time operating system instead of a general-purpose operating system such Microsoft® Windows® (Microsoft Corporation).
Selecting VME, VPX and VXI Controllers and Processors
Selecting VME, VPX and VXI controllers and processors requires an analysis of available technologies. The original VME bus (VMEbus) uses Eurocards, rugged circuit boards that provide a 96-pin plug instead of an edge connector for durability. VME64 is an expanded version of the VMEbus that provides 64-bit data transfers and addressing. VME64 extended (VME64x) is an improved version of the original VMEbus that features a 160-pin connector family, 3.3-V power supply pins, bandwidths up to 160 Mbps, injector/ejector locking handles and hot swap capability. VME160 transfers data at 160 Mbps. VME320 transfers data at a rate of 320 Mbps. VPX (a.k.a. VITA 46) is an ANSI standard based on the VMEbus with support for switched fabric using a high speed connector. VXI combines VMEbus specifications with features from the general-purpose interface bus (GPIB) to meet the needs of instrumentation applications. Other technologies for VME, VPX and VXI controllers and processors may also be available.
There are several form factors for VME, VPX and VXI controllers and processors. A computer board's form factor describes its shape and physical layout. It also determines the types of cases that can be used to contain the board, and the type of power supplies that can be used. The original VMEbus specification recognizes two types of cards: 3U and 6U. 3U cards, also known as single height boards, are 100 mm x 160 mm with one 96 pin DIN connector (J1 connector) on the rear that plugs into the backplane. 6U cards, also known as double height boards, are 233 mm x 160 mm with a second 96 pin DIN connector (J2 connector). For VXI systems, cards are lettered from A to D. Size A cards are 100 mm (3U) x 160 mm. Size B cards are 233 mm (6U) x 160 mm. Size C cards are 233 mm (6U) x 340 mm. Size D cards are 360 mm (9U) x 340 mm. VXI cards with a height of 360 mm (9U) and a length of 400 mm are also available.
VME, VPX, and VXI controllers and processors differ in terms of general specifications, processor type, operating system support, and ports and interfaces. General specifications include hard drive capacity, main memory, and additional storage media. Some products are hot swappable, feature CE Marking, or conform to requirements from the U.S. Federal Communications Commission (FCC). Others include watchdog timers, mouse connectors, keyboard connectors, or video support. Support for proprietary and open-source operating systems is commonly available. Many VME, VPX and VXI controllers and processors are used with Ethernet, GPIB, and universal serial bus (USB) products. VME, VPX and VXI controllers and processors with parallel ports and serial interfaces such as RS232, RS422 and RS485 are also available.