Archive for the ‘DMX’ Category

DMX – Whats that?

Friday, June 12th, 2009

DMX512-A is an EIA-485 based communications protocol that is most commonly used to control stage lighting and effects and LED lighting control.

Developed by the Engineering Commission of USITT, the standard started in 1986, with subsequent revisions in 1990 leading to USITT DMX512/1990. In 1998 ESTA began a revision process to develop the standard as an ANSI standard, including a Public Review process. The revised standard, known officially as “Entertainment Technology — USITT DMX512–A — Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories”, was approved by ANSI in November 2004. This current standard is also known as “E1.11, USITT DMX512–A”, or just “DMX512-A”, and is maintained by ESTA.

DMX512 was originally intended as a ‘lowest common denominator’ protocol for use between interfaces supporting proprietary protocols. However, it soon became the primary method for linking not only controllers and dimmers, but also more advanced fixtures and special effects devices such as fog machines and moving lights. DMX512 is unidirectional and does not include automatic error checking and correction, so it is not safe to use for applications involving life safety, such as controlling pyrotechnics or laser lighting display where audience or performer safety is involved. MIDI is sometimes used for this task.