Art-Net vs sACN — which protocol to pick
The dualETH-PixelControl speaks both Art-Net and sACN/E1.31. Each port is independently configured for one or the other. This article explains what each protocol is, how the device addresses universes in each, and which to pick for your setup.
What they are
Both are ways of carrying DMX-512 over Ethernet — they let a console talk to a node like the dualETH over a regular network cable instead of a long XLR run.
Art-Net is the older protocol, originally developed by Artistic Licence. It's open, very widely supported, and uses UDP broadcast or unicast on port 6454. Almost every console, software lighting tool, and node in the world supports Art-Net 3 or Art-Net 4.
sACN (also known as E1.31) is the ESTA-standardised lighting-over-IP protocol. It uses UDP multicast on port 5568, with each universe getting its own multicast group. This makes it much friendlier on busy networks — switches can prune multicast traffic so a node only sees the universes it's subscribed to.
How universes are addressed
This is where the two protocols differ most.
Art-Net uses a three-part address: Net (0–127) + Sub-Net (0–15) + Universe (0–15). That gives 32,768 unique universes. The dualETH defaults to Net 0, Sub-Net 0, with universes 0–3 on Port A and universes 4–7 on Port B.
sACN uses a flat 16-bit universe number from 1 to 63,999. The dualETH defaults to universes 1–4 on Port A and 5–8 on Port B.
These two numbering schemes are independent — Port A's "Art-Net universe 0" and "sACN universe 1" both go to the same physical DMX output, but the universe number you'd dial into your console is different depending on which protocol the port is set to.
Merge behaviour
When two sources send to the same universe at the same time, the dualETH merges them. Each port has a configurable merge mode:
| Mode | Behaviour |
|---|---|
| HTP (highest takes precedence) | Per-channel: whichever source has the higher value wins. The default. |
| LTP (latest takes precedence) | Whichever source most recently sent a value for that channel wins. |
The merge engine tracks two sources per port. If a third source starts sending, the merge is held to the first two until one of them goes quiet for ~3 seconds.
Practical recommendation
For most installations, start with Art-Net. It's the path of least resistance — your console already supports it, every other node on the market supports it, and the broadcast model means you don't have to think about multicast routing or IGMP snooping on your switch.
Switch to sACN if:
- You're running 8+ nodes on the same network and the broadcast traffic is starting to congest things.
- Your installation is in a venue with managed switches and an IT department that already runs IGMP snooping.
- Your console or media server only outputs sACN.
- You need the protocol to play nicely with non-lighting traffic on the same network.
You can mix protocols on a single device — Port A on Art-Net and Port B on sACN is fine, useful when migrating an installation from one protocol to the other.
What the LEDs show
Both protocols look identical from the LEDs' perspective. The TX LED for the relevant port flashes blue per packet received and pulses pink when there's no traffic, regardless of whether the incoming packets are Art-Net or sACN. If you need to confirm which protocol is actually arriving at a port, check the Per-port Status line on the dashboard — it shows the protocol name explicitly.