DMX512 Protocol
DMX512 — The Standard for Stage Lighting
DMX512 (Digital Multiplex with 512 channels) is the foundational protocol for stage, film, and architectural lighting. Every lighting professional needs to understand it.
Technical Specifications
| Parameter | Value |
|---|---|
| Standard | ANSI E1.11 |
| Physical layer | RS-485 differential pair |
| Connector | 5-pin XLR (3-pin XLR common in entertainment) |
| Baud rate | 250 kbps |
| Channels per universe | 512 (1-512) |
| Max cable length | ~300m (1000ft) |
| Topology | Daisy chain (max 32 devices per segment) |
| Refresh rate | ~44 Hz (full universe) |
How DMX512 Works
[Controller/Console] → [DMX Universe] → [Fixture 1] → [Fixture 2] → [Fixture 3]
512 channels Addr 1-10 Addr 11-20 Addr 21-30Each fixture listens for its assigned channels. A moving head might take 16 channels (pan, tilt, dimmer, color wheel, etc.), while a simple PAR takes 3 (RGB).
DMX for Pixel LEDs
To control individual pixels with DMX, you use a DMX decoder that converts DMX channels to pixel LED data. Each RGB pixel consumes 3 channels.
- SP201E — Cheap DMX-to-SPI decoder (~$10)
- PixLite / Falcon — Dedicated pixel controllers that accept DMX over Ethernet