While RDM is a relatively new protocol for most people, it\u2019s history now stretches back more than twenty years\u2026<\/p>\n\n\n\n
The High End Systems connection<\/strong> A key component of the HES Talkback protocol was the mechanism for discovering all the fixtures connected to the data link. The Discovery protocol had actually been in existence at HES since the release of Cyberlight back in 1994. The discovery protocol was developed by Status Cue Engineer, Shawn Dube, as part of a method for performing firmware updates in the fixtures. Based on a binary search algorithm, a popular Computer Science exercise, it\u2019s application across a DMX512 datalink was quite novel at the time.<\/p>\n\n\n\n DMX512\/2000<\/strong> After a contentious early draft of the document was released in the \nFall of 1999, Scott began attending the CPWG and DMX512 Task Group \nmeetings in January 2000. One of the issues with this draft was that it\n prohibited bidirectional communication on the primary pair of the \nDMX512 data link, something HES had been doing for years already and a \ncore requirement in the HES Talkback protocol. While bidirectionality \nwas never mentioned in the USITT version, it did specify RS485 which is \ninherently a bidirectional link. When this subject was broached during \nthe meetings that weekend saying the reaction to bidirectional \ncommunication over DMX512 was not well received would be a massive \nunderstatement. Saying the response was greeted with pitchforks and \nbats would be a bit more accurate. While the tar and feathers were \navoided, the group slowly warmed to the concept as it was informally \ndiscussed over the next 2 years.<\/p>\n\n\n\n The Start of Something New<\/strong> A New Standard is Born<\/strong> In 2010, a new revision of RDM was released adding a few improvements\n and making a number of corrections in the document discovered since \nit\u2019s initial release.<\/p>\n","protected":false},"excerpt":{"rendered":" While RDM is a relatively new protocol for most people, it\u2019s history now stretches back more than twenty years\u2026 The High End Systems connection Much of the early development work of what became RDM goes to the credit of work done at High End Systems (HES). Back in 1999, the predecessor to RDM was created<\/p>\n
\nMuch of the early development work of what became RDM goes to the credit\n of work done at High End Systems (HES). Back in 1999, the predecessor \nto RDM was created at High End Systems by Scott Blair while developing \nfirmware for automated lighting fixtures. Scott has a long running \ninterest in lighting communication protocols and after developing a few \nother bidirectional protocols that ran over DMX512 for management of \nonboard preset data in the fixtures, he turned his attention to \ndeveloping the HES Talkback protocol. At the time Scott was the lead \ndeveloper of the EC-2 outdoor fixture for HES. This project finally \nafforded Scott the time to explore his interests developing a protocol \nthat would allow for the full remote configuration and monitoring of the\n fixtures across the primary pairs of the DMX512 datalink.<\/p>\n\n\n\n
\nThat was the working name at the time for the massive effort in ESTA \nthat began in the late 90\u2019s in updating the USITT DMX512 standard \noriginally developed in 1986 which the entire entertainment lighting \nindustry is built on. The original USITT DMX512 standard was elegant in\n it\u2019s brevity of 5 pages. Being a communication protocol standard of \nonly 5 pages though, it left many details unaddressed and contained much\n ambiguity. The DMX512\/2000 project (which eventually became ANSI \nE1.11-2004) seeked to reduce the ambiguity by stretching that 5 page \ndocument into a hefty 70 pages, all while maintaining full backwards \ncompatibility.<\/p>\n\n\n\n
\nAll those that were originally the most opposed to bidirectional \ncommunication over DMX512 became the biggest advocates of formally \ncreating a new protocol. With the support from then HES CTO Mike Wood, \nthe intellecual property for HES Talkback was put on the table for ESTA \nto use. In July 2001, the CPWG voted to officially begin work on the \nRDM project and the first RDM Task Group meeting was held in November \n2001 following LDI. Using the HES Talkback protocol as the basis the \ngroup quickly began expanding the capabilities and preparing the first \ndraft. <\/p>\n\n\n\n
\nBy the time the group completed the 3rd Public Review cycle, the work \nwas done and the new standard was released in 2006 as ANSI E1.20. RDM \nbecame the first new standardized lighting protocol released in our \nindustry since DMX512 was released more than 20 years earlier. While \nRDM has come a long way from it\u2019s beginnings as HES Talkback, the core \ncomponents and guiding principals remain unchanged. <\/p>\n\n\n\n