LewLight Entertainment Technology

Some thoughts and ideas for Art-Net, part 3

December 28, 2013

It's about time I wrap this up - and I've saved my favourite gripe for last..

Let's talk IP

One of the basic concepts of IP networks is that each device has got a unique address, an "IP address". Without IP addresses, switches and routers in the network wouldn't know in which direction to pass on messages - in fact, devices wouldn't even be able to tell whether messages were intended for them or not. This is why your typical office environment is equipped with a DHCP server that assigns IP addresses automatically to any device you connect to the network.

In a show environment network you will want every device to have a fixed IP address though, so not to have to wait for the DHCP server to assign addresses on power-up and/or risk a device changing its address. The catch then of course is that in order to manually assign an IP address to a device it needs to have a configuration panel of some sort. For some devices that isn't an option, so to solve the problem Art-Net comes with an auto-configuration scheme which dictates that devices should default to a 2.x.y.z IP address along with a scheme for how to assign the x.y.z numbers in a clever manner.

So that's why I need to be on a 2.x.y.z subnet?

Yes - but only if you are working with devices of the kind mentioned above. If you're in the office, running an offline version of your show control system and a visualizer, then there is no need at all. In fact, if you're in an office environment then the last thing you may want to do is add a fixed 2.x.y.z IP address to your computer(s) to "comply with Art-Net".

All Art-Net messages work perfectly fine on any IP subnet. Any computer software that requires your computer to be configured to a 2.x.y.z subnet in order to transmit or receive Art-Net has been poorly designed and should be mended - and particularly those that insist on sending Art-Net data to the 2.x.y.z network on a machine that doesn't even have an IP address on that network. These should burn in a very hot and particularly unpleasant place.

If despite all this you believe you have good reasons for adding fixed Art-Net IP addresses to your computers and/or consoles in addition to your existing DHCP IP addresses then make sure you are armed with some very solid knowledge of IP networking.


History  

Full opening of the CITP protocol
March 13, 2016

The pitfalls of CAD
November 06, 2015

It's Chinese
August 08, 2014

PixelBeetle 1.1 update
June 25, 2014

Introducing PixelBeetle!
March 08, 2014

Some thoughts and ideas for Art-Net, part 3
December 28, 2013

Some thoughts and ideas for Art-Net, part 2
November 02, 2013

Some thoughts and ideas for Art-Net, part 1
November 01, 2013

Well hello there!
October 26, 2013