expanseElectronics

What is an Art-Net node?#

Last updated · 3 min read

An Art-Net node is a small box that sits between a computer network and your lighting fixtures. Your console or lighting software sends lighting data over an ordinary Ethernet network; the node turns that data back into DMX-512 — the signal fixtures actually understand — and sends it down an XLR cable to the rig. The same box is often called a DMX-over-Ethernet gateway, an sACN node, or just a node.

Why not just run DMX cable?#

DMX-512 is reliable, but it has limits that start to bite as a rig grows:

  • One cable carries one universe — 512 channels. A few moving lights or an LED batten can use that up quickly.
  • Long runs are a problem. Every universe needs its own run of DMX cable from the desk to the fixtures, and splitting or merging signals needs extra hardware.
  • Data only flows one way on a basic DMX line.

Putting the data on Ethernet fixes most of that. A single network cable can carry many universes, network cabling and switches are cheap and everywhere, and you can put a node wherever the fixtures are — at the top of a truss, in a lighting box, behind the set — instead of running a separate DMX line back to the desk for each universe.

What the node actually does#

  1. Your console or software outputs Art-Net or sACN (two protocols for carrying DMX over a network — see Art-Net vs sACN).
  2. Each packet is labelled with a universe number.
  3. The node listens for the universes it has been told to output, and drives each one out of a physical DMX port.

Many nodes also work in reverse: a port set to DMX in reads a DMX line (from an older desk, say) and publishes it onto the network.

How many ports and universes do I need?#

Count the DMX channels your fixtures use, divide by 512, and round up — that's the number of universes. Then think about where the fixtures are: each physical DMX line coming out of a node is one port, so fixtures in three different places usually means three ports, even if they'd fit in fewer universes.

If you have… Look at
One or two DMX lines, or LED pixel tape a 2-port node such as dualETH — it can also drive WS2812 pixels directly
Up to four independent DMX lines, or a mix of in and out a 4-port node such as quadETH
Several nodes to look after a management box such as masterETH, which finds every node on the network and shows them in one place

The comparison page has the full side-by-side specs.

Do I need a special network?#

For a small rig, no. A node works on an ordinary Ethernet switch, and a single node can even be tested with one cable straight from a laptop. As the number of nodes and universes grows, the network starts to matter more — see Lighting network basics for switches, IP addressing and multicast.

Next steps#