DMX512 is the most common version of this protocol and was first developed in 1986.

Basic Features

DMX sends a signal from a control device (typically a lighting console or computer) to one or more DMX-compatible lighting fixtures.

A single DMX line can control 512 different “channels”. Each channel can control a different parameter of a fixture (e.g., brightness, color, strobe effect, etc.).

Operating Principle

The DMX system operates between a “master” device and one or more “slave” devices. The master device, usually a DMX console or software, generates all control signals.

The master device sends a value between 0-255 for each channel. These values are used by the fixture for various functions (e.g., the brightness of an LED or the position of a motor).

DMX uses the RS-485 serial connection standard. Communication cable connections use three-pin XLR-3, XLR-5 sockets, or screw terminal blocks.

RDM and DMX

Often mentioned alongside DMX is the RDM (Remote Device Management) protocol, which is a two-way version of DMX. That is, with RDM, fixtures can send feedback to the control device.

Applications

• Stage and theater lighting
• Architectural lighting projects
• Concerts and events
• Club and bar lighting
• TV studios

DMX offers users full and dynamic control, but the system’s setup and usage can be a bit complicated. Especially in large systems with many fixtures and channels, DMX addressing and management require considerable attention and expertise.