Interface definition

• Connector
• Pin assignment
• Electrical characteristics

Interface description may include data format, data rate, cable length, mode of transmission, termination, bus common mode range, connector type, and system configuration.

The connector is defined by it shape, size, amount of pins it holds and the place the pins are mounted in the connector housing. Mostly it is built up of a shell (which contains the pins), the pins, the hood and something to mount it with like screw-locks or latches. The pin assignment describes which pin is connected to which circuit and thus describes the actual function of signal at the pin. The electrical characteristics describe the voltages, currents and shapes of the signals.

There are some standardization organizations responsible for many common interfaces standards:

• TIA/EIA (Telecommunications Industry Association/Electronics Industry Association)
• ITU (International Telecommunications Union)
• CCITT (International Telegraph and Telephone Consultative Committee) - now replaced by the ITU
• MIL-STD (United States Military Standards)
• FED-STD (Federal Telecommunications Standard Committee)