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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 Engineering Ltd. Artistic Licence has published the specification and made it available for anyone to use on a royalty-free basis, subject to the conditions outlined here.

History

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.

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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 I

The first version of Art-Net, now called Art-Net I, was written in 1998 and released soon after. Art-Net I used broadcast data for all transactions including the streaming level data. The reason for the use of broadcast was simply to remove the need for any network configuration on the part of the user.

Art-Net I was implemented on 10BaseT networks and used for a relatively small quantity of universes – perhaps 10 (the effective limit was approximately 40 universes). This very modest level of bandwidth use worked well with a broadcast topology.

However, with the wide scale adoption of RGB LED devices, the demand for channels grew and the broadcast topology became problematic. Broadcast data floods the entire network and appears at every node whether it needs it or not. Too much broadcast data overloads switches and nodes alike.

Art-Net II

In order to address this problem, Art-Net II was released in 2006. At power on, the Art-Net II output of a console is identical to Art-Net I – all broadcast. However, with Art-Net II, the console uses a simple algorithm to learn which nodes are consuming which universes. It then switches to unicasting to the nodes. The reduction in network loading achieved with Art-Net II is massive, allowing Art-Net II networks to scale up to the bandwidth of the network. Art-Net II has an effective limit of 256 universes.

Art-Net 3

The need for ever more channels, driven by the expansion of pixel based systems, continues unabated. This led to the release of Art-Net 3 in 2011. Art-Net 3 increased the number of universes that can be addressed from 8-bit to 15-bit (meaning that a total of 32,768 universes can be addressed). Art-Net 3 added a concept called Binding, which allows product designers to develop gateways with more than four ports. However, each logical block of four ports must have a unique IP address, which can be difficult to implement on some hardware platforms (the use of multiple IP addresses is called multi-homing).

Art-Net 4

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 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.

Art-Net 4 also has built-in support for VLC (Visible Light Communication).

Art-Net FAQs

Why Art-Net?

Using ethernet for transmitting lighting data has many benefits. The following lists a few:

  1. Ethernet (10BaseT/100BaseT) can carry up to 40/400 times as much data as a DMX512 cable.
  2. The computer industry is huge – using ethernet for lighting control provides access to a wide range of low cost products such as switches and radio links.
  3. Ethernet uses low cost cable that is readily understood by building contractors. This allows all of the lighting cable to be installed and certified before the lighting contractors start their installation.
  4. Many existing buildings are already wired for ethernet. This allows existing building cable to be used for retrofit or temporary lighting projects.
  5. Products for moving data around physical barriers, such as cityscape projects or crossing rivers, are readily available. These include a range of technologies such as wifi radio links, laser links and telephony systems such as leased line, ADSL, ISDN, VPN and so forth.
  6. All ethernet wiring is ‘star’ format. This increases system reliability compared to the ‘ring’ or ‘loop-through’ wiring used with DMX512.

There are a few drawbacks:

  1. The maximum cable distance is approximately 100m compared to 300m for DMX512. However the lower cost of ethernet switches compared to DMX512 splitters makes this a minor problem.
  2. All ethernet wiring is ‘star’ format. Generally this requires more cable. However, as ethernet can carry much more data that DMX512, there is still a net saving.

So is Art-Net the same as Ethernet?

No, Art-Net is the communication protocol that ‘sits’ on top of ethernet. An analogy is the way that DMX512 ‘sits’ on top of the RS485 standard.

What does Art-Net offer me that DMX512 does not?

In addition to all of the benefits listed above:

  1. It allows remote patching of all of the DMX512 inputs and outputs. This is a big benefit for installations with multi-purpose rooms.
  2. It allows DMX512 data to be merged in either LTP or HTP format. This can be used to include, for example, a house lights controller into a system.
  3. Features such as remote control of the lighting console are easy to implement.
  4. It supports the RDM standard, allowing the controller to retrieve information from the moving lights and dimmers. This also includes the ability to automatically patch all of the lamps.
  5. A lighting console’s video screen monitors can be transmitted over Art-Net to allow remote monitoring in, for example, the dimmer room.
  6. Free tools, such as DMX-Workshop, are available to monitor data at any point on the network from a central location.
  7. Perhaps most importantly, Art-Net is a royalty-free protocol that is supported by over 220 manufacturers worldwide.

Will ethernet replace DMX512?

No – definitely not. The real point of Art-Net is that it allows ethernet and DMX512 to work together, so you get the benefit of both worlds. For example, the ‘star’ wiring of ethernet would be a major annoyance for cabling moving lamps on a truss. The best solution is to take ethernet from the console to the truss and then convert to DMX512.

Can I use Art-Net with other systems?

Art-Net 4 is unique in that it allows use to choose 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 E1.31-2016 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.

Some systems like ETCNet and KiNet use ethernet but the language is different to Art-Net. The manufacturers have not published the technical information, so these protocols remain proprietary standalone technology.