The ESTA foundation recently released the new standard for DMX512-A or better known as ANSI E1.11-2008 Entertainment Technology – USITT DMX512-A, Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories. The standard are available for purchase on The ESTA Foundation’s Publications website.
ANSI E1.11 – 2008 is the most recent updating of the ubiquitous lighting control protocol that started with the USITT DMX512 standard in 1986. It corrects errors and clarifies text in the 2004 edition and adds functionality. An important clarification is the maximum update rate. The maximum rate is 44 Hz if 512 data slots are being sent, but it can be almost 20 times faster if a data packet contains fewer slots. This has been true ever since the original USITT DMX512, but some receiver manufacturers have missed or ignored this detail. The new edition also adds an Alternate START Code for UTF-8 transmission so that languages that can’t be rendered in ASCII can be used for sending diagnostic text messages. The 2004 edition only allows text messages encoded in the American Standard Code for Information Interchange (ASCII), which only supports American English and a few other languages that use the simple Latin alphabet.
The 2004 edition is now obsolete. Anyone designing new DMX512 products is encouraged to use ANSI E1.11 – 2008 rather than the old 2004 edition. However, the 2004 edition will continue to be sold on The ESTA Foundation website as a service to people trying to understand the requirements of a contract or request for quotation that references it.