DMX Glossary

Protocols and terminology

Term	Description	For more information:
DMX	A digital serial control protocol for entertainment lighting. Officially called DMX512-A, it was developed by the USITT and has become the standard protocol for entertainment lighting control using the RS485 physical layer.	DMX512
eDMX	A shorthand term for DMX-over-Ethernet protocols, see Art-Net, and sACN below.
Art-Net	A DMX-over-Ethernet protocol developed by Artistic Licence and widely used in the entertainment industry to distribute multiple universes of DMX data. Current supported version is v4 (transmitting only. v3 for other functionality).
sACN	Streaming ACN (Advanced Control Network), a DMX-over-Ethernet protocol developed by ESTA to distribute multiple universes of DMX data.	ESTA
Universe	A common term given to a single DMX data link or port. A DMX universe carries 512 channels of control data each with 8 bit resolution. A single dimmer will use one channel while more complex fixtures will use multiple channels as required.
DMX Address	The term used to determine which of the 512 control channels of a DMX universe a fixture should look at to take its own control data. This "start address" must be set on the fixture or dimmer rack itself as well as patching the control system.
Start Address	The start address is the first channel that the fixture will take control data from
Footprint	The footprint is how many channels the fixture needs to function. For instance, an RGB (red, green, blue) fixture has a footprint of 3, whereas an RGBWA (red, green, blue, white, amber) fixture has a footprint of 5.