DMX Switch (Art-Net, Single Channel)

Driver: dmx_switch

On/off control of equipment driven by single DMX channels over an Art-Net Ethernet-to-DMX gateway (for example an Enttec ODE) — star-ceiling projector power and twinkle inputs, effect toggles, hazers, DMX-controlled relay packs. One GEM device represents one Art-Net node and its DMX universe; each GEM zone is one DMX channel. Turning a zone on writes the zone's on_value (default 255) to its channel; off writes 0.

Which DMX driver?

Use dmx_switch for single-channel on/off functions. Use dmx_rgbw for 4-channel RGBW color fixtures. Both speak Art-Net to the same kind of gateway, but only one GEM device may own a universe — the driver refreshes full-universe frames, and two devices pointed at the same node/universe will fight. Put switches and RGBW fixtures on separate universes if both are needed.

Prerequisites

• An Art-Net DMX gateway (e.g., Enttec ODE) reachable on the LAN from the GEM server.
• The controlled equipment wired into the DMX universe with a known channel per function.
• UDP 6454 reachable outbound from the GEM host to the gateway (the default Art-Net port).

Setup

1. Configure the Art-Net node on the network and confirm it responds at a known IP on its Art-Net UDP port (default 6454).
2. Open the Devices page (System → Devices), choose Add Device, and pick the driver dmx_switch ("DMX Switch (Single Channel)").
3. Set the device's Art-Net Node IP to the gateway's LAN IP. Leave Art-Net UDP Port at 6454 and Art-Net Universe at 0 unless your node is configured differently.
4. For each switched function, create a zone under Zones: bind it to this DMX device, set its Address to the function's DMX channel (1–512), and set the zone's Control to light_switch for a simple on/off toggle.
5. If the equipment expects a specific channel value rather than full-scale, set the zone's on_value attribute (1–255).

Example — star ceiling with twinkle

A fiber-optic star-ceiling engine where channel 511 is projector power and channel 512 enables twinkle:

Zone	Address	Control	Notes
Star Ceiling	511	light_switch	on/off for the projector
Twinkle	512	light_switch	effect toggle

To present both as a single control, set one zone's Control to switch_bank and give it a zone_id attribute listing both zone ids (e.g. [12, 13]) — it renders a switch per listed zone under one control. Alternatively, zone_combiner with a zone_ids attribute stacks each zone's own configured control.

Attributes

Device

Attribute	Required	Default	Description
ip	yes	—	Art-Net gateway LAN IP (the Art-Net Node IP field).
artnet_port	no	6454	Art-Net UDP port on the gateway.
dmx_universe	no	0	Universe number on the Art-Net node (0–32767).
dmx_speed	no	40	DMX refresh rate in Hz (1–44).

Zone

Attribute	Default	Description
on_value	255	Channel value (1–255) written when the zone turns on.
value	—	Runtime — last channel value written (0–255). Written by the driver.
state	—	Runtime — on/off. Written by the driver.

Commands

Command	Args	Description
on	address	Set the zone's channel to its on_value (default 255).
off	address	Set the zone's channel to 0.
set_value	address, value	Write a raw channel value (0–255); state becomes on for any non-zero value.

Troubleshooting

Symptom	Check
Equipment does not react to "on"	Verify the zone address matches the DMX channel; try a specific on_value — some inputs want an exact level, not 255.
No response at all	Verify the Art-Net node IP and universe match the GEM device. Check firewall on the GEM host (UDP 6454 outbound).
Another DMX device stopped working	Two GEM devices are sharing one universe — each refreshes full-universe frames. Move one to its own universe.