diagnosing problems in computer communications, typically over a serial port. The breakout box sits between two pieces of equipment and usually has some LEDs to display the status of the different signals in the serial cable. It will also often have DIP switches to let the user connect or disconnect different signals in the cable. It will usually have connector pins that let the user short pins together using electrical jumpers or gain access to individual signal lines with an oscilloscope or other test equipment. RS-232 breakout box: Typically, RS-232 breakout boxes offer complete control of the RS-232 interface, test, re-wire, and open signal lines. These devices are pocket-sized for circuit testing, monitoring, and patching. They usually provide ten interface signal powered LEDs to permanently monitor TD, RD, RTS, CTS, DSR, CD, TC, RC, DTR (E) TC signals, as well as enabling the breakout of individual circuits or reconfiguration or patching any or all of the 24 active switch positions. Personal computer sound cards. A DA15 connector on the outside of the board is often broken out into DIN connectors for MIDI. Some professional audio applications use rackmount breakout boxes. A patch panel can also function as a breakout box, in the case of multi-channel DB25 (or other) connectors used for multi-track recording. Docking stations for notebook computers. These draw the signal for multiple connectors from the pins of one connector. Electronic control units (ECUs) in automotive engines have proprietary connectors that are densely packed, environmentally sealed, and difficult to gain access to without causing damage. The manufacturer sometimes provides a breakout box to allow service engineers to test the unit. References External links Telephony Input/output Electrical signal connectors Audiovisual connectors Computer connectors Electrical connectors