Lighting Ethernet

[Nick512]

The biggest issue with having an Ethernet switch built into fixtures is that if one fixture loses power, then all the other fixtures further down the chain will lose their data signal.

 

Really Wouldn't a simple rechargeable battery in the fixture allow this switch to run for hours even if it lost power? or POE?

 

I don't think that Ethernet distribution directly to each fixture will be used widely used anytime soon, there's just no compelling reason for doing it.

 

I disagree, I think it would be a huge advantage. There are too many reasons to name why I would want it.. here are a few off the top of my head.

 

1. Your installing 200 Heads around a football stadium all 3m apart all the way around the roof line... with an ethernet link system you start at one end a you only need 200 x 3m ether-con cables.. a really neat job of data easy to trouble shoot.. tell each light its universe and address and your done. Think of the amount of Standard DMX Cables and buffers/ repeaters you would need to make this work and how hard it would be to find a fault in the cabling...

 

2. A Tour with a Heavy truss.. you often run out of space on a universe.. it is so much simpler to get local crew to go in and out of all the lights on the truss in a chain without having half on one chain and half on the other.. this would save time.

 

3. want to add some lights to an audience truss way out in the house you but you have a full universe of lights and only and 1&Spare DMX Line there.. means you should have to add 2 more DMX lines.. the sets already in which means hours of climbing but with ethernet you can just address to a spare universe.. and off you go...

 

I can go on and on..

 

I'm not sure if there is a theoretical limit to the number of daisy-chained switches, but each switch does add a short delay of a few microseconds - and these add up!

 

I think your right.. there will be a limit and there will be some delay added but... I am using the PRG Series 400 Power Data System at the moment.. which is ethernet based.. it links rack modules together using this daisy chain system.. I have 64 linked together in this way, these 64 then split out to another 128 Break out boxes which again have another 3 port switch inside where its converted back to DMX.. Its running 36 full universes Constantly and I do not experience any noticeable delay.. Even though the majority of my trunk runs are over 600 feet long..

[martinw]

1. Your installing 200 Heads around a football stadium all 3m apart all the way around the roof line... with an ethernet link system you start at one end a you only need 200 x 3m ether-con cables.. a really neat job of data easy to trouble shoot.. tell each light its universe and address and your done. Think of the amount of Standard DMX Cables and buffers/ repeaters you would need to make this work and how hard it would be to find a fault in the cabling...

Thats an amusing example. For the last fixture in the chain to get data, you'd be relying on 199 other devices to actively repeat and route the signal, good luck with that!

 

I'm not sure if there is a theoretical limit to the number of daisy-chained switches, but each switch does add a short delay of a few microseconds - and these add up!

For an unmanaged layer 2 switch, 20uS seems to be pretty typical for 100M Ethernet, going to 10uS for 1G. These figures are for 64byte packets though, so with streaming ACN and Artnet the latency will be greater.

 

I am using the PRG Series 400 Power Data System at the moment.. which is ethernet based..

Is this available in Europe yet or only in North America?

 

Martin