Definition of breakout box in The Network Encyclopedia.
Breakout boxes are specific examples of a more general category of network testing equipment called “status monitors.” Status monitors are available for testing a variety of serial interfaces, including RS-232, RS-449, V.35, and X.21. They generally come with a variety of connectors and are quick and easy to use for isolating problems with serial transmission connections in networking, telecommunications, and industrial settings.
Breakout Box RS-232
Testing RS-232 wiring and connectors.