Is it possible to run sACN on a network with other traffic?

[Robin Larsson]

As the title says, I´m wondering if its possible to run sACN, or Artnet for that matter, on a network that also has other normal traffic? It should be, right? 

I want to make a system were I can use a laptop or tablet to run Lightjams, control one or more sACN-DMX nodes, and also run control signals to a Speaker management system/DSP that sits in an amprack next to the stage. Preferably via WiFi.

In the future I´m looking at upgrading to a better digital livemixer, with a digital stagebox connected via ethernet cables, then it would be great to be able to run sACN over the same cable at the same time (to much latency in WiFi to run live audio). It would most likely be some mixer manufacturers proprietary protocol then, or possibly Cobranet or similar. I´m not sure that most of those protocols would be able to share a network with other protocols, but perhaps? 

Anyone tried something in that direction? 

It would be really nice to be able to control both sound and light from the same pc/tablet, and without cables :)

[Robin Larsson]

It would also be fantastic to be able to run ILDA signals via the same ethernet connection, if it would be from a future version of Lightjams (a guy can dream?;)) or a different program, perhaps even on a different computer, but using the same cable/wifi link would be great :) Not sure if that works with for example Etherdream or other Ethernet-ILDA solutions,but hopefully :)

[Mathieu]

Hi Robin,

No problem as long as your wifi is good enough! With artnet, make sure to use unicast since the default broadcast mode can destroy the network performance very quickly. sACN uses multicast, so it performs better out of the box.

[Jason Kyle]

Almost!

sACN uses multicast but your network switch must “understand” multicast and pipe it to the right ports. Most people miss this bit and think multicast fixes everything however it can be just as bad as broadcast if the network switch doesn’t support IGMP and have an IGMP querier built in as well. If no IGMP support is present in the switch multicast traffic is “broadcast” out every port anyway.

My recommendation would be to use Art-Net unicast since this works with all network switches. 

Watch out with wifi though, there are so many potential interference sources you can’t control (a sea of smart phones with wifi hot spot enabled) which you probably won’t encounter during testing but will most certainly see during an event. Personally I go for cables wherever possible.

Best Regards, 

Jason Kyle

DMXking.com / JPK Systems Limited

[Robin Larsson]

Thank you Mat and Jason!

Sounds good that it should be possible atleast:) Thank you Jason for your in depth knowledge about the network side of things! I´ll look for a wreless router that supports IGMP. As you say, wireless is prone to interference, but personally I have had very little problems with wifi, but I havent tried it at events with hundreds of smartphones yet so.

Oh, and btw, Jason, I sent you an email about a year ago, asking if you had any plans on a wifi enabled Art-Net interface, you replied quickly, but for some reason I completly forgot to answer your email, I´m sorry for that! May I ask if you have done any further development in that area this last year? 

One thing that I have been thinking about when it comes to using wireless, is a solution where you use a rackmounted or even trussmounted very small computer, preferably in a rugged case, with a built in Art-Net/sACN interface (to get multiple universes) and let that computer run Lightjams, and then control it via wifi, either from just a smartphone or smaller Andriod tablet running TouchOSC, or from a Windows laptop/tablet via remote desktop, using Midi controllers if possible.

In that case the actual DMX signal creation is done at the stage, so even if one would loose contact with the wifi network completly or experience heavy interference, the lightshow would still go on, just without operator input until wifi can be restored.

That is basically the same as it would be to wirelessly control the Xilica XD 8080 DSP that I´m considering, only controlsignals would be sent through wifi, not the actual audio signals. 

That kind of solution would be very good for all the smaller gigs I do where the lightshow is mostly unattended, but where it would still be nice to be able to take some control over it, without having a FOH position with a lot of gear and cables running to the stage.

Now I usually use a small simple dmxcontroller from Stairville for those kinds of gigs, but I want to switch over to only using Lightjams, its soo much better :)

Best regards

Robin Larsson

[Igor Ebner]

I can give some information about digital mixers to you:

Allen & Heath iLive: ACE Network (Audio and Control Network) will transfer just some single channels from surface inputs to the stagebox (as example if you have connected a CD player to the surface directly). All microphone input channels from the stagebox will not be transferred over the network cable to the surface, they will be mixed internaly inside the stagebox itself. So you can still transfer some artnet and remote protocol trough the same network cable.

Allen & Heath GLD (dSnake) and Behringer X32 (AES50 protocol): All Stagebox microphone input channels will be transferred trough the network cable from stagebox to surface, and the outputs back to stagebox with minimal latency. So there is no traffic resource for any other protocol. The network cable needs to be connected from surface to stagebox directly without any hubs/switches.

Im sorry, i dont have any experience with Cobranet.

Workaround: Ethernet Network 100MBit needs just 4 wires. A CAT-5 network cable has 8 wires. You can just build an adapter from 2x Ethernet -> 1x RJ-45 on the surface side, and another adapter from 1x RJ45->2x Ethernet at the stagebox side. Then you can use two independend Ethernet networks at one single cable:
- one for Artnet and DSP Remote control
- and one for the stagebox.

[Robin Larsson]

Igor, Thank you very much for your very detailed answer! I´m sorry it took so long time for me to respond..

I have not decided what mixer I´m going to get next, it will likely be a while before we buy one, right now we are not really doing any livesound shows, only have one planned so far this year so cant justify a new digital mixer now :( 

I looking over our entire digital sound and light structure at the moment, we need new SDP systems for our PA´s, and I want to go digital as far as possible, but that is a bit difficult with all different systems out there now. Even if we can get AES3 out from our Live mixer, our Pioneer DJM-850 mixers only have S/PDIF out, havent seen any DJmixer with AES.. Stupid things like that irritate me :P Also we need a better computer-solution for the lights, before my current laptop with Lightjams breaks down.. 

Thank you for your very smart idea about the Ethernet adapter to run two networks on one cable, brilliant idea!

I´ll have to get me an Arnet/sACN node to start testing that also :)

As always, there are waay to few hours in each day...

[Igor Ebner]

By the way: SPDIF and AES has the same protocol, just SPDIF is an unbalanced signal and AES is a balanced signal. So you can use simple signal converters to adapt them.

[Robin Larsson]

Yeah, I know that they are very similar :) But are they really exactly the same signals? I´ve read somewhere that there are some small differences but that most newer products can handle that. I havent tried, I only have one DSP with AES inputs, and we dont really use that one right now :) 

There are converters, like this one: http://www.hosatech.com/product/339824/CDL-313/_/Digital_Audio_Interface%2C_SPDIF_Coax_to_AESEBU

But it seems like it could work with just an RCA-XLR cable also, I´ll have to try :D

Still its irritating that manufacturers get use the same standards and connectors, why cant all digital pro audio stuff have atleast AES? Alot of people are "scared" of digital audio, and I think that is a big part of why not all digital products have digital connectors, which gives us more A/D and D/A conversions, which make the whole thing worse, and make people more scared ;) Isnt it almost retarded that a digital CD/USB player uses analog cables, to a digital mixer, that then sends analog signals to a digital DSP that then feeds the amps with an analog signal??? Sure it works, but still, 2 sets of completly unnecessary D/A and A/D conversions..

I guess that Pioneer for example dont have digital inputs on the DJM-850 mixer just to make people buy the much more expensive DJM-900 instead, but still, the DJM-800 had digital inputs, but not the upgraded version of it... 

Rant over :P

[Igor Ebner]

Ive never tried it by myself, so i cannot guarantee that this is really compatible. Your doubts are justifiable.

[Robin Larsson]

I´ll try if I get some time over and report back when/if I´ll get it done :)