DMX

DMX, or DMX512 (Digital Multiplex) is a standard for digital communication networks that are commonly used to control stage lighting and effects. It was originally intended as a standardized method for controlling light dimmers, which, prior to DMX512, had employed various incompatible proprietary protocols.  DMX can handle up to 512 unique channels. 

A DMX512 network employs a multi-drop bus topology with nodes strung together in what is commonly called a daisy chain. A network consists of a single DMX512 controller – which is the master of the network — and one or more slave devices. For example, a lighting console is frequently employed as the controller for a network of slave devices such as dimmers, fog machines and intelligent lights. 

An example of a DMX Cable, which is a 5 pin XLR cable, is below:
800px-DMX_Cable

Read more at the DMX entry at Wikipedia >>