DMX which is short for DIGITAL MULTIPLEX, is the type of signal that is sent between a lighting board and a lighting fixture. It's the main form of communication between the two pieces of equipment. It allows the light board to tell the lighting fixture what to do.
DMX is divided into Channels. There can be a maximum of 512 channels sent through one cable. These 512 channels are commonly known as a universe.
Lighting fixtures use different amounts of dmx channels based on the complexity of the fixture. 1 channel may control the pan of a mirror or yoke, the 2nd channel may control the tilt, the 3rd may control the gobo (picture) and the 4th may control the color. More complex fixtures will use more channels for more options.
In order to have control over a lighting fixture individually, an address must be specified for each fixture. This allows the light board to communicate with a specific lighting fixture. This is achieved by setting the starting address of the fixture. For example if we were to set up 4 lights and control them by a lighting board that assigns dmx channels in increments of 16, we would start with channel number 1, so the first light we would set to channel number 1. The second light would be addressed to channel number 17. The 3rd light would be addressed to channel 33 and the 4th fixture would be addressed to channel 49.
