Architecture for Control Networks (ACN) is a suite of network protocols for theatrical control being developed by Entertainment Services and Technology Association (ESTA). The first official release is formally referred to as ANSI E1.17 - 2006 - Entertainment Technology - Architecture for Control Networks.
It was designed as a replacement for DMX as the control protocol for lighting systems and can be used for controlling more complex devices like video playback servers (media servers) and audio mixers. The protocol is designed to be layered on top of UDP/IP and therefore will run over standard, inexpensive Ethernet and 802.11 (Wi-Fi) network links.
ACN relies on UDP in order to pass its messages. Where reliability is required, the Session Data Transport sub protocol allows semi-reliability of only the latest value for a particular "channel".
Art-Net is a proprietary protocol for transmitting the lighting control protocol DMX512-A (with RDM) over the User Datagram Protocol of the TCP/IP suite. The protocol was developed by Wayne Howell and his company, Artistic Licence Engineering (UK) Ltd, and is open for implementation with attribution but without charge , and make available a Software Development Kit. It is typically implemented as lighting-control nodes in embedded controllers, driven from a lighting desk or similar software operating as a server. Art-Net compatible products are made available by dozens of companies.
Art-Net is a simple implementation of DMX512-A protocol over UDP, in which packets containing lighting settings are transmitted over IP packets, typically on a private local area network such as Ethernet. Facilities exist to transmit or receive lighting data (eg, fader levels for individual lights or positions of movable lights), as well as management functions such as detecting the nodes available or updating their control parameters, or transmit timecode. More sophisticated functions include subscription, so that for example, nodes A and B can subscribe to node C; C will unicast information to A and B.