recommendations for distributing DMX though-out an auditorium

[Jay Ashworth]

Further to the comments of teq, sk8r and others, though we may be veering off course for the OP:

If you're involved in putting in new copper for a facility -- especially if it's a complete rewire, or new work -- *think structured cabling*.

Cat 5A or 6, all locations either home-run or run to an IDF; at least 2 cables per position, and 4 isn't unreasonable in some cases.

Remember the first rule, when speccing:

Copper is cheap. People are expensive.

Put in as much copper as you can possibly afford, consonant with your long-term expansion goals... and remember: damn near *everything* can be run over 568B Cat cable these days.

 

[BillConnerFASTC]

I laid out a simple wired dmx distribution system gor a storefront thatre and sent them to several dealers. Just got this report with identifying names deleted. Conract me off line if you want to contact dealer.

"<sales rep> from <dealer> came down a couple of weeks ago and sold me on wireless DMX— he said our proposal will state that if we ever have a show go down due to wireless failure, <dealer> will pay to install a wired system for us free of charge."

Significant sabings btw.

 

[cbrandt]

Wow, that's a pretty big guarantee. I'd like to be that confident in any gear, wired or not.

I wonder what the final language on that guarantee will actually look like. I hope they put a time limit on it.

 

[BillConnerFASTC]

Wow, that's a pretty big guarantee. I'd like to be that confident in any gear, wired or not.

I wonder what the final language on that guarantee will actually look like. I hope they put a time limit on it.

All shared observations. It is a 30' x 50' all one room storefront performance space - so no obstructions.

 

[JonCarter]

Spectacular or unbelievable "guarantees" are wonderful--as long as the guarantor doesn't go out of business. Will the guarantor be around for the expected life of the facility he's guaranteeing? An outfit that makes spectacular or unbelievable guarantees may well be a newbie in the biz who doesn't know what he's talking about.

 

[BillConnerFASTC]

Major dealer who has been around a long time and is well respected. I can't say they offer this to every project of any size, but they did add gear to one that had some issues.

 

[Mike WSSR]

Bill, why do you suppose they are pushing wireless so hard?

 

[RonHebbard]

Bill, why do you suppose they are pushing wireless so hard?

@Mike WSSR Time and labor saved on installation. Labor and installation costs ALWAYS cost more than materials, especially if / when you're installing rigid or EMT conduit after the fact exposed on finished surfaces as compared to installing conduit in a poured concrete slab during construction. Non union labor is expensive. Union labor is more expensive (but I prefer to believe we do better work). [Retired from IBEW 105, IATSE 129 and 357]
Toodleoo!
Ron Hebbard

 

[RickR]

As @RonHebbard said, plus the theatrical dealer gets those funds rather than an installing electrician, of any variety.

The other major claim is flexibility. "Put your DMX where you want it, when you want there." It allows replacing many jacks that might be used someday with fewer wireless ones, which often means delaying rather than reducing costs.

 

[BillConnerFASTC]

I am just in midst of another very small project - just lighting system for small school - and the "wired" package - relays and dmx distro - was $45,000 + $70,000 pipe and wire and electricians versus $60,000-65,000 if all the theatre dealer after the building was built. Not all projects are the same - neither for suitability of wireless not costs - but generally, to the question why wireless when you can do wired - the answer is cost.

 

[macsound]

Asking an ArtNet question here that I haven't tried personally before and haven't found a solid answer on anywhere else.
Can I have multiple nodes outputting the same DMX universe?
Like one node FOH and one node on stage, each outputting 1-512.
<edited to fix punctuation>

 

[Jay Ashworth]

Asking an ArtNet question here that I haven't tried personally before and haven't found a solid answer on anywhere else.
Can I have multiple nodes outputting the same DMX universe?
Like one node FOH and one node on stage, each outputting 1-512.
<edited to fix punctuation>

I suspect, strongly, that that's going to be implementation dependent on each receiving node. Betting the spec says no explicitly.

[ EDIT: The spec says "yes", explicitly, as you'll see below. Well, maybe. ]

 

[sk8rsdad]

The Art-Net standard supports multiple nodes outputting to the same DMX universe. Any number of nodes can choose to subscribe to receive the same packet. I suspect it's a pretty common occurrence.

https://art-net.org.uk/structure/streaming-packets/discovery-subscription/

 

[Jay Ashworth]

Well, I'll be damned. Nice. When you say "nodes can subscribe to receive the same packet", though, I get confused. I would assume that a receiving node could only be set to receive *by universe*, one for each physical port it has (absent fancy merging tricks).

Are you saying that I can have multiple senders per universe, and nodes can *pick which ones to hear*?

That seems unnecessarily complex.

 

[Jay Ashworth]

The Art-Net standard supports multiple nodes outputting to the same DMX universe. Any number of nodes can choose to subscribe to receive the same packet. I suspect it's a pretty common occurrence.

https://art-net.org.uk/structure/streaming-packets/discovery-subscription/

That page doesn't actually support that assertion, I don't think. It talks about multiple nodes, but with only one controller. The OP is asking about multiple *controllers* sending the same Universe number to 1 or more listening nodes.

 

[sk8rsdad]

Art-Net supports having multiple senders too, but that's not the same thing as having multiple receivers. In the case of multiple senders, a node has to decide what to do about a conflict: ignore, error out, or merge.

https://art-net.org.uk/structure/streaming-packets/merging/

I took the OP's question to mean multiple nodes outputting the same DMX universe, not multiple controllers sending to the same node.

 

[Jay Ashworth]

Ah. No, I'm pretty sure the OP was talking about "multiple lighting desks originating the same numerical universe". If the spec specifies a behavior for merging received such data, that will still solve his problem.

I personally assume "multiple nodes converting and outputting the same universe" is the basic use of Artnet.

 

[macsound]

I actually was wondering about multiple notes outputting the same universe of DMX, so I'm in good shape.
Thanks!

 

[BillConnerFASTC]

Can I have multiple nodes outputting the same DMX universe?

the OP was talking about "multiple lighting desks originating the same numerical universe

It does not compute.

 

[Jay Ashworth]

Sure it does.

The first is "multiple Artnet/sACN nodes extracting data off an IP network and converting it to DMX *on a single physical cable".

The second is "multiple light boards *creating* Artnet/sACN data for a single numbered DMX universe, and injecting that onto *the same* IP network, such that the nodes see "universe 1" data coming from more than one IP address, possibly with conflicting levels".

Totally different, and distinguishable things... you just have to be careful with your nouns.

I'd thought from his phrasing that the IP meant the latter, which is much more complicated than the former; turns out I was worng.