Yesterday I posted about DMX-512 dimmer. DMX-512 is a lighting industry standard way of controlling lighting equipment.DMX-512 allows for one controller (like a lighting desk or computer) to control many lights from many manufacturers. DMX-512 fundamentally provides 512 channels of 8-bit resolution (0-255) level control(which constitue a DMX ‘universe’) using serial RS-485 communications at 250 kbps/s data speed. DMX-512. DMX-512 was created in 1986, with subsequent revisions in 1990 leading to USITT DMX512/1990, and updated version“E1.11 – 2008, USITT DMX512-A” was approved by the American National Standards Institute (ANSI) in November 2004
Nowadays when there is a trend that all the communications is converging to use Ethernet, the has been several task forces in converting lighting control to Ethernet. One standard to this direction is ESTA’s BSR E1.17, the “Architecture for Control Networks” protocol (ACN) developed by the live entertainment industry for control of pretty much anything. It is an entirely new protocol.
There are also work going on somewhat simpler approach where you you combine DMX-512 devices and transport the communications over Ethernet where that suits best. For example there are situations where it makes a lot of sense to use computer to send control data to Ethernet network, and at location near the actual lighting equipment convert it to DMX-512 signal. There are several competing protocols for this:Art-Net, Shownet and E1.31 (also called Streaming ACN). There are Art-Net and sACN compatible software, both free & commercial. (FreeStyler, Madrix, Jinx, LoR(E1.31) ……….)
Art-Net is a communications protocol for transmitting the DMX512-A lighting control protocol and Remote Device management (RDM) protocol over the User Datagram Protocol (UDP) of the Internet Protocol suite. It is a trademark of and copyright by Artistic Licence Holdings Ltd., which released the protocol specification into public domain and allows the protocol to be used subject to attribution, but without royalty. Art-Net uses a simple UDP based packet structure designed to provide efficient and low overhead data flow. Art-Net was created by Artistic Licence to overcome the channel restriction of DMX while still utilizing its structure: allows multiple DMX universes to be transported over a single Cat5 cable using ethernet technology. Art-Net I was implemented on 10BaseT network and it uses broadcast. Art-Net II was released in 2006 and it can also use unicast communications. The protocol specification is available for download from the Artistic Licence web site.
E1.31 (also called Streaming ACN) is a protocol for sending DMX512 data over the ACN (E1.17) family of protocols. Streaming ACN (sACN) is a standard protocol developed by ESTA to efficiently transport DMX universes over the network. It is comparable to ArtNET in many aspects. One nice thing is the multicast option allowing very easy configuration. sACN is a popular protocol to control large number of RGB LEDs. E1.31 is expected to become the new standard for transporting DMX over IP, replacing other protocols such as ArtNet and Shownet.
Interesting looking projects related to Art-Net:
ArtNet arduino set v3.1 has implementation of ArtNet receiver and sender working
chris‘s library also implements receiving DMX, working with EtherCard (i.e. the ENC28J60).
Nat‘s library can receive multiple universes and has examples for the NeoPixel library and OctoWS811 libraries. It works with the standard Ethernet library
Interesting looking projects related to sACN: