showstack / protocols / dmx512
DMX512
Also called DMX, DMX512-A, USITT DMX512.
The unidirectional serial protocol that has controlled stage lighting since 1986. 512 slots of 8-bit data per universe, sent continuously over a differential pair, with no error checking and no acknowledgement.
Stewarded by ESTA (Entertainment Services and Technology Association).
Control
Small, urgent, must arrive
Small messages that either repeat constantly or fire once. Bandwidth is almost never the problem.
What kills it. Latency and loss on the messages that fire once. A repeating level survives a dropped packet; a GO does not.
Addressing
One universe = 1 start code plus up to 512 slots of 8-bit data, refreshed up to about 44 times per second.
What goes wrong
DMX is RS-485 and wants 120 ohm impedance cable with a terminator at the far end. Microphone cable works until the run is long or the rig is noisy, and then it fails in a way that looks like a fixture fault.
There is no error detection. A corrupted slot is simply acted on. Flicker that follows no logic is usually a data integrity problem, not a fixture.
Star topology is not part of the standard. Daisy chain, or use a real opto-splitter. Passive Y-splits are the source of an enormous amount of unexplained behaviour.
Start code 0x00 is dimmer data. Other start codes exist (0xCC is RDM), and a device that ignores start codes will act on RDM traffic as if it were levels.
What speaks DMX512 (54)
54 products — 28 hardware, 26 softwareshow all
| Product | Direction | Notes |
|---|---|---|
| ArKaos MediaMaster ArKaos |
in | Direct DMX in via an interface. |
| ArtNet Monitor (PixiLab) PixiLab |
in | Displays per-channel DMX values received via Art-Net. |
| The ArtNetominator Lightjams Inc. |
in | Displays current DMX channel values and channel history as carried inside Art-Net packets. |
| ArtNetView Haute Technique |
in | Displays DMX universe values (including in hex) as carried inside Art-Net. |
| Avolites Titan Avolites |
out | Physical DMX512 on console XLR outputs; on a PC, via a T1/T2/T3 interface. DMX In is a separate trigger source on supported consoles. |
| ChamSys MagicQ ChamSys |
out | Direct DMX via a MagicDMX interface, a MagicQ wing/interface, or console XLR outputs. MagicDMX is one universe, out or in. |
| Chataigne Ben Kuper |
bidirectional | |
| Daslight Daslight (Nicolaudie) |
out | DMX via the bundled interface. |
| DMX-Workshop Singularity (UK) Ltd |
bidirectional | |
| DMXcat City Theatrical, Inc. |
bidirectional | Measures break time, mark-after-break, inter-slot timing, refresh rate, and real-time channel levels. |
| DMXControl 3 DMXControl Projects e.V. |
out | DMX out via supported USB interfaces. |
| Eos Electronic Theatre Controls (ETC) |
out | Local DMX ports on consoles, or an ETC Gadget/Gadget II USB to DMX-RDM converter on a PC or Mac. Up to four Gadgets per computer. |
| ETCDmxTool ETC Labs |
bidirectional | Captures DMX data and can output/control DMX levels via ETC Whip/Gadget hardware. |
| Home Assistant Open Home Foundation |
out | Through integrations, and not a substitute for a lighting control system. |
| Isadora TroikaTronix (Mark Coniglio) |
out | Video can be pixel-mapped to RGB DMX values and sent out via USB-DMX devices. The lighting page says DMX input and output but only output is described in any detail. |
| Lightkey Lightkey |
out | DMX out via USB interfaces. |
| MadMapper garageCube |
bidirectional | |
| Medialon Control System Medialon (Barco) |
bidirectional | DMX via interfaces. |
| Millumin Anomes (Philippe Chaurand) |
out | Direct USB-DMX output; docs list Enttec DMX USB Pro and Pro Mk2, DMXking ultraDMX Micro and ShowJockey interfaces. |
| OLA (Open Lighting Architecture) Open Lighting Project |
bidirectional | Through more than twenty supported USB DMX widgets. |
| ONYX Obsidian Control Systems |
out needs licence |
Direct DMX needs Obsidian USB hardware (NX-DMX, NX-Touch, NX-K, NX-P) or an NX console. Onyx USB output appears from the NOVA tier upwards, not in ONYX FREE. |
| QLC+ QLC+ project |
bidirectional | Via the DMX USB plugin and supported USB widgets. |
| RDM Controller JESE |
bidirectional | DMX output and monitoring alongside RDM. |
| Show Cue System (SCS) Show Cue Systems |
out | DMX output via interface. |
| TouchDesigner Derivative |
bidirectional | |
| vvvv vvvv group |
bidirectional | Through interfaces. |
| Avolites Arena Avolites |
out | Direct outputs. |
| Avolites Diamond 9 Avolites |
bidirectional | Direct DMX out of the rear XLRs. |
| Avolites Tiger Touch III Avolites |
out | Direct DMX from the rear XLR5 outputs. |
| ChamSys MagicQ MQ80 ChamSys |
out | Direct DMX outputs. |
| ChamSys MagicQ MQ500M Stadium ChamSys |
bidirectional | Direct DMX from the rear XLR5 ports. |
| Christie Pandoras Box Christie |
bidirectional | DMX via interfaces. |
| City Theatrical Multiverse Transmitter City Theatrical |
bidirectional | Wired input and output. |
| ELC dmXLAN node8 ELC Lighting |
bidirectional | Eight ports. |
| ENTTEC DIN Ethergate MK2 ENTTEC |
bidirectional | Two universes. |
| ENTTEC DMX USB Pro ENTTEC |
bidirectional | One 512-channel universe; the linked input and output ports are used in one direction at a time. |
| ENTTEC ODE Mk3 ENTTEC |
bidirectional | USITT DMX512-A on two 5-pin XLR ports, each settable as input or output. |
| ETC Eos Apex 10 ETC |
out | Direct outputs. |
| ETC Ion Xe 20 ETC |
out | Local DMX out via the rear ports. |
| ETC Response Mk2 DMX/RDM Gateway ETC |
bidirectional | DMX out and in on the physical ports. |
| ETC Sensor3 Dimmer Rack ETC |
in | DMX input as a backup or primary path. |
| ETC ThruPower Rack ETC |
in | Control. |
| grandMA2 full-size MA Lighting |
bidirectional | Direct DMX from the rear XLR5 ports. |
| grandMA3 full-size MA Lighting |
out | Six DMX512-A outputs on 5-pin XLR female. |
| grandMA3 full-size MA Lighting |
in | One DMX512-A input on 5-pin XLR male. |
| MA Lighting grandMA3 light MA Lighting |
out | Direct outputs. |
| Hog 4 High End Systems |
out | Eight Neutrik XLR-5 outputs, 8,192 output channels onboard. |
| LumenRadio CRMX Nova TX2 LumenRadio |
bidirectional | DMX in on the XLR, DMX out wirelessly to CRMX receivers. |
| Luminex LumiNode 12 Luminex Network Intelligence |
bidirectional | DMX out and in on the XLR ports. |
| Medialon Showmaster Pro Medialon (Barco) |
bidirectional | Through interfaces. |
| Obsidian Control Systems NX4 Obsidian Control Systems |
out | Four DMX ports on the console itself. |
| Pathway Connectivity Pathport OCTO Pathway Connectivity |
bidirectional | Eight ports. |
| Wireless Solution W-DMX BlackBox F-2 G6 Wireless Solution |
bidirectional | DMX in or out on the XLR ports depending on mode. |
| Zero 88 FLX S48 Zero 88 |
out | Two DMX outputs on the rear. |
Open source implementations
- OLA (Open Lighting Architecture) — C++, LGPL-2.1-or-later
- DMXSerial (Arduino) — C++, BSD-3-Clause
Typical use
- Console to dimmer, moving light, LED fixture, hazer, or scenic effect
- Last-metre delivery from an ethernet gateway to fixtures on a bar
- Triggering non-lighting devices that accept a DMX channel as a go signal
The words for it
Glossary entries that name DMX512, with the false friends that catch people out.
Daisy chain串接Wiring devices in a straight line, in and out, rather than back to a central point. DMX and RS-485 in general…DMX addressDMX 位址A numbered control slot from 1 to 512 within one DMX universe. A fixture's start address is the first slot it…Universe一條 DMX 線路 (universe)One complete DMX512 stream of 512 channels. Everything about rig capacity is counted in universes: a console …Patch配接（patch）The mapping between a control channel and the thing it drives. On a lighting desk it is which DMX address a f…Unit load單位負載The standard reference load an RS-485 bus segment is rated against — one unit load is roughly a 12 kΩ receive…
Sources
- ANSI E1.11 — USITT DMX512-A, Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories — ESTA Technical Standards Program primary
Understand the mechanism
Something wrong, or missing?
Known gaps on this entry: default_ports. If you can source one of them, that is a ten minute pull request.
Edit this entry on GitHub — one file, editable in your browser, and your handle goes on it permanently.
Work at ESTA (Entertainment Services and Technology Association)? Confirm or correct this entry — it is free, it stays free, and nothing about it is for sale.