DMX

From YSTV Documentation Wiki

DMX is a digital lighting control protocol, in which instead of 1 core of cable for each channel used (like on the Lighting Desk), 512 channels of control are transmitted down 3 wires: Data+, Data-, Gnd, with ground usually being the sheild or braid, Data+ & Data- are a twisted pair.

Current supported devices

  • Chamsys MagicDMX dongle
  • Eurolite DPX405 dimmer
  • DMX outboard & Analogue to DMX system

Infrastructure

DMX requires a cable impedance of 120ohms. So you must not use microphone cable! All DMX equipment operates at 120ohms. Equipment is "daisy chained" together, and each device has an input and an output (they must be the correct way round).

YSTV runs 2 universes down a single Cat5e cable, as this is a very close impedance, and it is actually quite common to use Cat5e to run DMX

Connections

These are on 3 or 5 pin XLR. Currently, all YSTV DMX equipment uses 3 pin XLR

DO NOT plug dmx into any sound gear or use audio cables as a substitute, something will get fried.

Pinouts

Cat5e

Dmxcat5.png

Useful Notes

Don't run DMX right next to audio cables of any kind unless completely unavoidable, even if everything is balanced. You will hear the DMX data - The sync pulses manifest as an intermittent tone & noise.