Ethernet-based lighting control protocol transmitting DMX512 data over IP networks, supporting up to 63,999 universes of 512 channels each.
Technical Details
sACN transmits DMX512 data in UDP packets over multicast addresses in the range 239.255.0.1 to 239.255.251.255. Each universe occupies a specific multicast address, with universe 1 corresponding to the address 239.255.0.1. The packet size is a maximum of 638 bytes, consisting of a 126-byte header and up to 512 DMX channels. The protocol supports priority levels from 0-200, with higher values taking precedence. Integrated universe discovery allows for automatic detection of available universes on the network.
History & Development
sACN was developed in 2006 by the Entertainment Services and Technology Association (ESTA) as a cost-effective alternative to proprietary Ethernet DMX solutions. The first implementation occurred in 2008 in ETC's Eos series consoles. In 2009, E1.31-2009 was adopted as the official standard, followed by the expanded version E1.31-2018 with improved discovery functionality. Today, virtually all modern lighting consoles and LED controllers natively support sACN.
Practical Application in Film
In film productions, sACN enables the centralized control of distributed LED panels and RGB fixtures over a single network. In "Blade Runner 2049" (2017), the lighting team distributed sACN signals via a fiber optic backbone to hundreds of Skypanel units for cityscape lighting. Modern Virtual Production Stages, such as those used for "The Mandalorian," utilize sACN to synchronize LED walls with practical lighting. The workflow typically includes a central sACN-enabled dimmer/controller, network switches, and sACN-to-DMX nodes for conventional fixtures.
Comparison & Alternatives
sACN primarily competes with Art-Net (developed by Artistic Licence), with sACN being considered the official standard and offering better multicast performance. Art-Net uses broadcast packets and is limited to 32,768 universes. MA-Net (grandMA) and other proprietary protocols offer advanced features but restrict device compatibility. For small setups with fewer than 10 universes, traditional DMX512 over XLR remains more cost-effective, while sACN demonstrates its strengths in more complex installations with over 512 channels.