DMX Primer
The basics of DMX, universes, channels, and addresses.
If you're new to lighting control, this page help you understand the basics of DMX and how it works. If you already know the basics, you can skip this page.
What DMX is
DMX512 is the standard that lighting consoles use to talk to fixtures. It's a one-way stream of numbers: the console sends values, and the fixtures listen and react. There's no feedback coming back.
Channels and values
The stream is made of channels, and each channel carries a single value from 0 to 255. A channel controls one thing on a fixture: its dimmer, its red level, its pan and so on. A simple dimmer uses one channel, while a moving head might use twenty or more.
Universes
Channels are grouped into universes of 512. One universe is one DMX line, so it can carry up to 512 channels of control. A small rig fits in a single universe, and larger rigs spread across multiple universes.
Addresses
Every fixture has an address, which is the channel where its block of channels begins. A fixture that starts at address 10 and uses four channels listens to channels 10, 11, 12, and 13. Set two fixtures to the same address and they'll do exactly the same thing, so most of the time each fixture gets its own range.
Fixtures and modes
A fixture's mode decides how many channels it uses and what each one does. The same light might have a simple mode with a handful of channels and a full mode with many more. Picking the right mode matters, because it tells the software how to lay out that fixture's channels and what each channel does, from its address onward.
How this maps to nextDMX
In nextDMX, you can patch fixtures to a universe and address, and the app will handle the rest. nextDMX handles which channel does what. The app then sends the finished universes to your rig.
If you want to connect nextDMX to a real rig, you'll need a DMX interface. nextDMX currently only supports Art-Net and sACN over Ethernet. There are many interfaces available and plenty of guides online for how to connect them to your computer and your fixtures. Once you have a working interface, you can set it up in nextDMX's DMX Output settings.