batchmaker.de - Lighting Control and Routing Applications
ArtNet by Artistic Licence
So what is it ? It's a protocol like AOL. Yes AOL is in technical terms a protocol, too. Like the better known http, ftp, telnet and so on. Protocols are rules someone has to follow if they want heir stuff working with other machines. Easy said.
So this company Artistic Licence is building metal boxes which have a ethernet plug on the one side and USITT DMX512 plugs at the other side.
USITT DMX512 is well known in the entertainment industry cause it's the industry standard for controlling dimmers and automated lighting fixtures (moving lights). The electrical standard of DMX512 is RS485 which is as superset of RS422 which almost the same as RS232, well known as serial port on a PC.
Ethernet is the electrical standard that transports data based on TCP/IP, well known as a standard in todays internet. Based on TCP/IP there are several protocols 'running' like http, ftp, aol, and so on. One more is ArtNet which uses UDP packets.
So far so uninteresting.
The point is that this protocol standard is published (on their website) and so open for anyone to use who wants to control light. This is in the first place no big deal cause anyone can publish as many protocols as they like.
The big deal is that major vendors of lighting gear (control desks, dimmers, e.g.) support ArtNet. The inquiry is to see if a product has an ethernet plug and ongoing if this ethernet plug understands ArtNet.
This inquiry is yes for some products of ADB, MA Lighting, High End, Avolites, Doug Fleenor and others. And now for the Mac, too.
As long you do not code it's quite easy cause you just wire the ethernet between ArtNet safe products and it works. You even can place networking gear in the middle that does not know about protocols (routers, switches, bridges, hubs and perhaps fences) to route this data across the internet to another place.
In the use your desk is the source of data which is distributed across some ethernet in the house where to the output devices.
So where's the big deal against DMX512 ? ArtNet can carry up to 256 DMX Universes on the ethernet, not just one like a DMX512 cable.
Your desk, outputting usually one to eight universes all blows them out on one port. Saving you a lot of cables. Also, if you move the desk you may plug it into a different ethernet wall box and it works. With DMX512 cables you'd have to lay several cables to the new physical position. If you have wireless networking gear you'd even not need to lay one ethernet cable...
But how do the dimmers get the right signal. They're still dimmers with twelve channels and a DMX plug and a DMX starting address ?
Well, with ArtNet it's the same like with DMX. You lay this bus around the house, usually today it's already there, inject the data from the desk and extract it with some kind of listener. These listener are called ArtNet nodes. A node takes it input from ethernet and gives out DMX512 which you wire to your dimmer rack, moving lights and so on. These listeners can be mounted directly in the wall, physically fixed, or can be boxed that you can put them one the front truss and one the back truss.
In an enviornment where you have 40 moving lights in the front truss and 80 moving lights in the back truss you'd have to lay at least two DMX lines to the front and four to the back. Summed up six cables from the desk. With ArtNet you just lay a ethernet to the front truss and place a node there. Nodes are available with any combination of input (yes DMX input if you don't have ethernet in the desk) and outputs. So on the front truss a two out node is needed and on the back truss a four out node is needed.
These nodes get adresses like DMX gear gets addresses. In ArtNet (what is distributing universes) there are sixteen subnets which each have sixteen universes which ends in the mentioned 256 DMX universes carried by ArtNet.
Subnetting is just a different way to name the individual DMX universe ! Cause usually you'll not need more than sixteen DMX universes at an area in the house. So in the above sample you could say that the fronttruss is subnet one using universe 1 and 2 and the backtruss is subnet two using universe 1,2,3 and 4. The other way would be using one subnet and universe 1,2,3,4,5 and six. (In this approach you have to know where the universes are going).
Lastly in studio complex with different control rooms and studios its easiest to say each studio gets its own subnet and in the control rooms the desk is switched to the needed subnet - which in fact then is one studio. So the universe numbering within a studio can be uniform in all studios; e.g. Left wall universe one, right wall universe two and so on.
Still no big deal ? Right. But ... the nodes have switches for the universe and the subnet like a DMX512 device has. So if you need a different DMX universe on the plugs just turn the switch and there you are. That's the big deal. You can reuse these nodes as you need ! The nodes even can be configured remotely - which means that you do not have to crawl up the truss to change the subnet or universe. And, still the big deal, your DMX devices can be shifted away to diffrent channels even if their DMX address on their cable remains the same. Cause you reconfigure the node... Which in fact then also makes a repatch in the desk neccassery - but that's a lot easier then to crawl the truss.
That's it for the basics. With some paper and some expirience you're able to lay out a whole theme park with different control rooms as long as you distribute your data right.
Now Artistic Licence has an app for Windows called "Art Net View" to reconfiguere the nodes. So in this theme park it's possible to claim control over the whole park or studio complex during the night to control it from one place (say, that the outdoor lighting is on the individual studios dimmers, in the daytime controlled by the studios' control room) and during the night from another place (the studios' control room is empty and off, the night guard is the only one) to turn off outdoor lights at 22.00hrs. This could be even done from an automated central desk using some macro functionality to control the networking reconfiguration.
Now it's the end. This was an extensive example on how one can use the ArtNet to ensure proper work of theirs equipment... I know how to implement things like that, perhaps you too, but gracefully the majority of users needs to hire experts like us to make it work. And the will be using Windows for it...
At least here my interests split cause I am using Macs. The artist species in general likes this machines because they are friendly and easy to use. I know this and that's the way my ArtNet/Mac stuff will be. There will be two kinds of apps. First the useless (in the way of aboves sample) which you can download to monitor your ArtNet and do some tiny things. Second the commercial apps which wrap all of the above into a Mac application.
What I will not support in the near future is replacing the control desk with a Mac. As usual the first idea with something new isn't the best one.
Even if it is possible to save the desk, cause the Mac (or any PC) that can reconfigure, also can send the data itself it is a pain to control lights with the keyboard and a mouse.
The computer machine is fine for
- monitoring usage hours of bulbs
- censoring data like moving lights not reaching positions which would offend somebody
- ranging values of lamps to be at least 20% and maximum 50%
- supporting upcoming things like RDM or ACN
But these machines are not made to be a lighting control desk. Furthermore none of the three big OSes (Mac, Linux, Win) ensures you real real time capabilities.
More information about the ArtNet Protocol itself and some more extended programming info can be found in the ArtNet discussion forum at www.artisticlicence.com