Art-Net 4 is an award-winning data distribution protocol that allows DMX512 (hereafter DMX) and RDM lighting data to be transported over an Ethernet network. It uses a simple UDP based packet structure designed to provide efficient and low overhead data flow. Art-Net is owned and copyright by Artistic Licence Holdings Ltd. Artistic Licence has published the specification and made it available for anyone to use on a royalty-free basis. However,
DMX was designed to control up to 512 channels (a universe) of lighting values over a single cable. It worked well for many years but eventually outgrew its 512-channel limit, and lighting desks supporting several DMX universes began to appear. Soon, even this was not enough as the development of channel hungry fixtures progressed, and designers needed more channels than DMX could offer.
Art-Net was created by Artistic Licence to overcome the channel restriction of DMX while still utilizing its structure. It allows multiple DMX universes to be transported over a single Cat5 cable using ethernet technology.
In the early days, DMX signals from a lighting desk were converted to Art-Net using a separate interface product. The signals were then transported over an ethernet network and converted back to DMX before entering each fixture. However, manufacturers quickly saw the benefits of Art-Net and started to support the protocol in their new lighting controllers. As a result, native support for Art-Net in consoles, dimmers and moving lights is now quite common, so increasingly the DMX512 universe is a virtual concept.
Art-Net 4 was released in September 2016. It is the most powerful and flexible version to date and, in recognition of this fact, gained a PLASA Award for Innovation.
Art-Net 4 overcomes the multi-homing problem, by incorporating a new method of handling gateways that support multiple DMX ports. The scheme allows a gateway (or any Art-Net product) to support over 1000 DMX ports, all on a single IP address. It has been added in such a way that it is 100% backwards compatible with previous releases of Art-Net.
Art-Net 4 also offers a unique new feature that facilitates the management of the gateway data source. This allows users to choose Art-Net as the discovery, management and RDM tool while using sACN for the live control data. While many users are happy to work completely within the Art-Net realm, some installations and specifiers require or prefer the use of sACN, the accredited ANSI E1.31 standard. However, unlike Art-Net, sACN does not support network management or RDM, which could leave users disadvantaged. Art-Net 4 solves this problem, offering an elegant solution that enables the protocols to be used in a complementary manner.
Developers will also appreciate a new software feature that enables all DMX ports to be assigned a fully independent universe.
Finally, in a nod to the future, Art-Net 4 already has built-in support for VLC (Visible Light Communication) – a technology that is likely to have a huge impact in the coming years.
The protocol specification is available for download from the Artistic Licence web site.