Depends on what the existing infrastructure is. You can but a centralized art net node and run DMX cable out of that to the fixtures or you can go the distributed route with a network switch and nodes spread out near your lighting positions. In my church we have a Chauvet Net-X connected via art net to our console and then DMX (ran over cat5) to our lighting positions. Works great for us.
First plan to use Cat5 for the permanent cable runs, this allows for expansion of the system down the road. Depending on your console the best answer is to start with a network connection out of the console so you can get multiple universe's on one cable. You run this to a rack where you start setting up a distribution point. From the distribution point you can use a network switch, go with a pro grade with POE. Run from the distribution point to locations near your lighting positions and don't forget stage level. Here is where you switch from network to DMX with nodes. Since you want multiple universes this is the easiest way to get them spread out. Once you switch to DMX you still may need opto-splitters if any run will get near the 32 load limit. For anyone else if you can't jump past two universes still put in the CAT5 because you can have opto-splitters at the first distribution point and then later when you need more channels you can switch the dumb output jack for a single port node which fits in the same single gang box. That is why the switch wants to have POE.
If you distribute a DMX signal, it should either be over cable specifically designed to carry RS485, (i.e. 120 Ohm nominal impedance), or it should be shielded CAT cable (CAT5 is OK, but you can always 'hedge your bet' and go with CAT6A to further 'future-proof' the installation). The CAT cable nominal impedance is very close to the EIA RS485 spec and is generally approved for DMX. The only difficulty is physically terminating the CAT type cable into the back of the XLR connectors - it can be a bit fragile so handling it carefully as you stuff it in the back-box is important.or just running a ton of dmx cable?
If you distribute a DMX signal, it should either be over cable specifically designed to carry RS485, (i.e. 120 Ohm nominal impedance), or it should be shielded CAT cable (CAT5 is OK, but you can always 'hedge your bet' and go with CAT6A to further 'future-proof' the installation). The CAT cable nominal impedance is very close to the EIA RS485 spec and is generally approved for DMX. The only difficulty is physically terminating the CAT type cable into the back of the XLR connectors - it can be a bit fragile so handling it carefully as you stuff it in the back-box is important.
If budget is an issue, also to be considered is the use of DMX buffered receptacles like those made by Doug Fleenor Designs or Goddard Designs. These are essentially a 'private' DMX buss that connect all the receptacles together that the end-user does not connect directly to, so each outlet can have up to 31 devices attached. The nice thing about this is if the student screws-up and shorts the DMX line, the whole system doesn't fail, just the one line they have connected to. You will need to provide a separate pair of wires to power the buffered outlets. They run off of 24 VDC, so depending upon how many buffered receptacle plates and how long the run is from the power supply, you can calculate the optimal size wire to deliver the power without excessive voltage sag (IxR loss in the wire). The advantage to this system is that you run a single pair of data and power cables out to a series of up to 31 receptacles. This can save substantially with respect to having to home-run each DMX or Data cable from each receptacle back to a DMX opto-splitter or a Data Switch (if network based). If you are installing this in conduit (highly recommended to protect the cabling) then the conduit can be significantly smaller (about 1/2" to 3/4" EMT), whereas if you have twenty outlets that each must be home-run the conduit size can increase significantly. The Goddard Designs device will pass RDM, too (not sure about the DFD device).
You can make a hybrid system, too: run a network line and DC power out to a data-to-DMX Node at an electric batten or catwalk, then install a dozen or more buffered DMX receptacles along the batten or catwalk. This lets you assign the universe separately to each electric batten and catwalk. (This could also be done by using a high quality DMX opto-splitter that has a network input.)
The trade-off as to how many 512 channel universes you may need at a given location should be considered. More and more lighting devices chew-up 30-100 DMX channels, so 512 channels may not go as far as it used-to, particularly if you are using the devices in 16 bit mode. This is why installing cable that home-runs all the way back to a switch location becomes necessary for more complex locations. More wire = larger and/or more conduits. Conduit is worth every penny when it comes to efficiently pulling cables through a building and protecting cabling from damage in the rough-and-tumble world of stage production. When you leave cables exposed for stuff to snag upon - stuff will snag upon it -- guaranteed.
I don't know. I was told this by an etc rep. Maybe they were wrong but usually a very reliable source. Perhaps one of the etc folks who post here will answer your question.
@BillConnerFASTC there might be some context or caveats missing from that limit from the ETC rep.
For DMX, the limit is 32 unit loads which may be much more than 32 devices depending on the device and the cabling, as has been discussed many many times before. An ETC node is fully compliant in that regard and fully supports splitters or any other DMX device with no practical limit on the total quantity downstream of the gateway.
Where things get complex is with RDM merging. There are limits to the number of RDM devices that can respond via the gateway since the gateway has to queue up the RDM responses from all the downstream devices and serialize them for the upstream controller. The internal buffer is finite, as is the patience of any controller waiting to receive the RDM data from all the devices.
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