ITT Test Plugs & Test Jacks
Test plugs and test jacks are used in electronics to provide a connection between a device and an external testing circuit. Test plugs and test jacks are used to make quick connections between two wires and devices while testing, debugging, and troubleshooting digital and analog circuits. The main difference between plugs and jacks, is the direction of the connection. In a plug, the connections are one-way for a given port, where in a jack, the connection is two-way. In a jack, the connections can be swapped such as with a serial or Ethernet connection, or made permanent. Plugs and jacks are also available in numerous shapes and sizes. Many plugs and jacks are keyed to prevent mismatching of the connections.