DMX over Cat5

[agbobeck]

I know that there are already some articles on this site about this topic but i just wanted to get some confirmation. A production I am designing this summer is using a space with no traditional data runs from the booth to the stage, but it does have 3 RJ45 and Cat5 runs from the booth to the stage. in order to use those as my data run, do I need to have a networked system or can i just us an adapter from 5 pin DMX-512 to rj45?

Thanks Folks,

Aaron Bobeck
Lighting Designer- Wildwood Summer Theatre
[email protected]

 

[Lsly]

I know that there are already some articles on this site about this topic but i just wanted to get some confirmation. A production I am designing this summer is using a space with no traditional data runs from the booth to the stage, but it does have 3 RJ45 and Cat5 runs from the booth to the stage. in order to use those as my data run, do I need to have a networked system or can i just us an adapter from 5 pin DMX-512 to rj45?

Thanks Folks,

Aaron Bobeck
Lighting Designer- Wildwood Summer Theatre
[email protected]

No network necessary, just an opti spliter. You do have to be careful with the adapter, there a few different options and the pin outs don't always match. I have had to build CAT5 cable adapters so that this issues was resolved.

LS

 

[agbobeck]

No network necessary, just an opti spliter. You do have to be careful with the adapter, there a few different options and the pin outs don't always match. I have had to build CAT5 cable adapters so that this issues was resolved.

LS

would you recommend building my own adapter? also the opti splitter would just be for convenience of distributing the dmx signal right? we own a elation optobranch 8 and I would like to not have to replace it with one with a cat5 feed.

 

[Lsly]

would you recommend building my own adapter? also the opti splitter would just be for convenience of distributing the dmx signal right? we own a elation optobranch 8 and I would like to not have to replace it with one with a cat5 feed.

Yes opti would go after the Cat5 adapter, and would provide a boost to the signal. Important if you have long CAT5 runs. But MAY work without one. It would be best to look at a standard for this. Here is what ETC has to say about ithttp://www.etcconnect.com/community/wikis/products/knowledgebase-dmx-over-cat-5.aspx
Building your own would depend on your skill level with soldering and whatnot. You can buy these pre-made, ENTTEC makes a good one.

LS

 

[JD]

Since Cat5 is the same impedance, you can treat it the same way as regular DMX with some important exceptions:

1) It's solid wire, so you don't want it in an application where it is flexed.
2) It is not shielded, so it should be in metal conduit. (That will provide the shield. It may work on it's own, but the signal may be noisy and you will never know how much until it stops working! )

Needless to say, use a single pair for the data (pins 2 & 3), do not group or double up on pairs which may be tempting as there are so many unused! Also, make sure there are no active network components in the line. It has to be just a copper run.

EDIT: ETC gives the layout for two data lines. My own practice when using a single data line it to tie all unused conductors to pin [HASHTAG]#1[/HASHTAG], as that helps provide a little shielding.

 

[Beans45601]

2) It is not shielded, so it should be in metal conduit. (That will provide the shield. It may work on it's own, but the signal may be noisy and you will never know how much until it stops working! )

Or just use shielded cable, which is what I used to run my permanent DMX line from the booth to the stage.

 

[LightingGuy89]

http://www.cpoint-lighting.com/products/product_DMXcompander/index.htm

There was a thread going on about these recently; I've used similar products but never this specific one. Might be a good way to utilize your resources. As somebody else said above though, Cable Length is very important when it comes to this and make sure there aren't any network components (Switch, PoE inserter, etc...) otherwise you could fry your fixtures.

 

[techieman33]

If you can send artnet or sACN from your console you could one of these, they also come in 2, 4, and 8 universe models. I've had the one universe model for about a year and it's been rock solid. I use it with a wireless router and switch to let me use my phone as a focus remote since my console doesn't have that feature, but does put out artnet. I also use it with lumenair to run small shows in the theater, and ballrooms so I don't have to sit at a console, or have someone else do it.

 

[Footer]

Just buy these and be done with it... http://shop.bmisupply.com/ProductDetail/3390030_Cpoint-Rj45-To-Xlr5m-Adapter

Don't worry about the shielding.

 

[gafftaper]

I agree with Footer. The Cpoint adapters are dirt cheap, work great, and your problems are solved. No need to get fancy, just put one on each end and pretend there's a DMX cable in the middle.

 

[jglodeklights]

As long as you know they are direct runs, I also agree. Just use adapters, and put your splitter in place after the adapter on-stage. If you can't tell, it wouldn't necessarily hurt to buy a cheap ENTTEC or similar $99 opto to put before your first adapter. Optos save gear (a company near me didn't wire something in their LED Tape setup correctly and fried three dimmer packs and a console because nothing was isolated and I've seen a surge protected console fried from voltage passed through the DMX line).