Commercial Item Description
A-A-55094
Connectors, Electrical, IEEE 488 Compatible, Rectangular, Miniature, Polarized Shell, Plug, 24 Position, Discrete Wire Cable Terminating, Bail Locking
Cable-End IEEE-488 Locking Bail Connector
Military specification A-A-55094 [MIL Spec] defines an IEEE-488 connector which terminates to a cable via discrete wire, separate wires. The GPIB side is secured by a locking bail. Note that many of the standards that required a bail to secure the mating of two connectors have fallen into disuse. When the two connectors need to be secured a jack post or screw post is used and not a metal bail. The connector shown above contains the latch portion and does not have the bail portion, which would be found on the mating connector. The cable side of the connector includes the latch portion [55094] while the equipment side contains the bail section [55140], as in IEEE488 Connector.
Main description of the General Purpose Interface Bus [electrical, mechanical & protocol]
General document requirements for a polarized shell, plug, electrical digital interface bus connector. This connector can be used in applications that require conformance to the IEEE 488 interface standard, and require termination of a discrete wire type cable. Connectors are intended for commercial/industrial applications and shall not be used in military systems needing stringent environmental and electrical requirements.
The term polarized shell refers to the physical shape of the connector. The mating portion of the connector takes the form of 'D' shape, which means the mate will only interface with the connector in one direction.
GPIB Practical Usage; GPIB connectors would be used in Automatic Test Equipment [ATE] gear. The system controllers would use the IEEE488 interface and this GPIB connector to communicate with each other. A controller, such as a computer, would request measurement data captured by a test instrument to be sent and then recorded for processing. The controller could also command a piece of equipment to take a measurement, or start or stop taking measurements. The GPIB connector and its interface are used to remotely control test equipment, so an operator does need to command the gear by using the front panel. Or test equipment might be automatically commanded at preprogrammed times to output signals into another interface [on a different electrical interface].
As memory dropped in price and more equipment began using internal storage; the GPIB interface could also be used to down-load stored measurements from one piece of equipment to another, such as a computer for analysis. This interface standard has been around since the 1980's long before any type of meaningful amount of IC memory was being utilized by lab equipment, or computers for that matter.
