Which DMX cable to use?

[steve1981]

I have been asked to rewire the DMX cables in a local bar and was wondering which cable you guys all use and which you would recommend? I know its twin core shielded, but I mean where to buy it from and also considering cost into it.

 

It is for a bar running around 8 or 9 fixtures and will be run in the ceiling.

 

All comments welcome.

 

 

Thanks,

Steve.

[KevinE]

I would use the Blue Room search. This has been covered so many times on BR that we'd be repeating ourselves to elaborate further!

[smalljoshua]

BR WIKI > DMX Cable

 

See the last paragraph.

 

Josh

[steve1981]

I would use the Blue Room search. This has been covered so many times on BR that we'd be repeating ourselves to elaborate further!

 

I've had a look around the site, but can't find anything? Can you show me where please?

[smalljoshua]

At risk of repeating myself.

 

The last paragraph of the page I linked to above states.

 

The DMX512-A standard states that Cat 5 cabling is also an acceptable option when used in a permanent installation.

 

Josh

[steve1981]

At risk of repeating myself.

 

The last paragraph of the page I linked to above states.

 

The DMX512-A standard states that Cat 5 cabling is also an acceptable option when used in a permanent installation.

 

Josh

 

Im sorry to make you repeat yourself Josh, but I understand now that cat 5 cable can be used, I was just looking for other peoples opinion and to see what they used. Ideally I was after some URLs of what people use. But one thing on cat 5, so do I just buy cat 5 (4 twisted pairs) and use three of them and cut the tohers off? Is that what companies use for installs?

 

Steve.

[smalljoshua]

Just use 1 of the twisted pairs, if you buy FTP/STP cable i.e. the cable has a screen. You can use the screen as Pin 1.

 

If you buy UTP i.e. the stuff without a screen, just connect pins 2 and 3 to one of the twisted pairs only. It has been discussed on here more than once and I believe the general consensus is that either methods will work just fine.

 

A little bit of advice though, when terminating, terminate in boxes not on flying leads as the Cat5 Cable is solid core ans wont really stand up to being put on a flying lead. Also, make sure you remember which of the twisted pairs you use. It may also help to mark the Boxes as to which pair you use as in the future, it will help the person who may have to takeover from you.

 

Josh

[steve1981]

Thanks for the advice Josh. I never knew that you could use that cable. Doesn't it really matter then if it has a shield/ground connected? I thought it would have.

 

And when you say terminate, I always just use a plug with 120ohm resister in and plug it into then end fixture. Is this wrong?

 

Would you also recommend ONLY using neutrik plugs? Or not a definate necesity?

 

Steve.

[smalljoshua]

I used the word terminate to describe how each end of the wire is treated.

 

If you decide to use Cat5, you will have to have a wall box at either end of each run of Cat5 with a XLR connector in because Cat5 cable is 1 solid core not many stranded cores inside each of the 8 conductors. This makes it less flexible and more likely to break if you just connect the Cat5 directly to a trailing XLR Plug/Socket plugged into the fixture because there is the ability for the cable to flex from the point where it leaves the wall and where it goes into the connector.

 

I only use Neutrik connectors simply because they are better than any of the copies out there.

 

As I briefly mentioned above, you will need a wall box with XLR connectors on at each end of every cable run. You will need to then run a short patch lead from each wall plate to the fixture(s) looping each one back to the wall plate and onto the next wall plate.

 

You are correct in thinking that to terminate the whole DMX chain, you use a 120ohm resistor.

 

Josh

[niclights]

Personally I'd forget all that. While the cable might be a bit cheaper it is negated by having to make boxes/patch leads etc.

 

I recommend Tourflex Datasafe. It's pretty much standard in touring and you can connect direct to XLR's without messing with boxes etc. Neutrik is not essential at all. They are certainly durable, but for install it won't matter.

[steve1981]

I used the word terminate to describe how each end of the wire is treated.

 

If you decide to use Cat5, you will have to have a wall box at either end of each run of Cat5 with a XLR connector in because Cat5 cable is 1 solid core not many stranded cores inside each of the 8 conductors. This makes it less flexible and more likely to break if you just connect the Cat5 directly to a trailing XLR Plug/Socket plugged into the fixture because there is the ability for the cable to flex from the point where it leaves the wall and where it goes into the connector.

 

I only use Neutrik connectors simply because they are better than any of the copies out there.

 

As I briefly mentioned above, you will need a wall box with XLR connectors on at each end of every cable run. You will need to then run a short patch lead from each wall plate to the fixture(s) looping each one back to the wall plate and onto the next wall plate.

 

You are correct in thinking that to terminate the whole DMX chain, you use a 120ohm resistor.

 

Josh

 

So this way themoney that I will be saving on cat 5 cabe will be spent on XLR wall sockets and the extra plug at each output? If it is a fixed installation, c't I just wire the cat5 cable into the XLR plugs that go into the light? They're not going to be unplugged all of the time like a mobile or theatre rig.

 

Steve.

 

A concurrent post has been automatically merged from this point on.

 

Has anyone got any website where I can purchase the cable from?

[bruce]

c't I just wire the cat5 cable into the XLR plugs that go into the light? They're not going to be unplugged all of the time like a mobile or theatre rig.

 

You can do that. Or you can do it properly.

 

CAT5 installation cable is solid core. Not intended for flying leads.

[steve1981]

c't I just wire the cat5 cable into the XLR plugs that go into the light? They're not going to be unplugged all of the time like a mobile or theatre rig.

 

You can do that. Or you can do it properly.

 

CAT5 installation cable is solid core. Not intended for flying leads.

 

But it is on a permenantly installed light. What would you recommend?

[Modge]

Would you also recommend ONLY using neutrik plugs? Or not a definate necesity?

If you buy neutrik you know you're buying good (and very expensive connectors). When I've wanted to make my self adapters \ terminators I've stuck to neutrik. If however I was trying to fit out a bar where a) They're unlikely to be unplugged and reconnected that often and b) You're buying enough of them that it'll cost a lot but not so many that you'll get the best price breaks. Then I'd be tempted to try something cheaper. Do be aware though that some of the cheapies (oftern as not unbranded) are less pleasent to solder and under heavy use (though less so in an install) will fall to bits after a while.

 

Cable wise I've seen this: http://www.vdctrading.com/products.asp?SubSectionID=5 used (and terminated quite a lot of it my self one way and another) quite a bit and it seems good.

[smalljoshua]

How are the lights laid out?

 

If they are all bunched together with the controller at the other end of the room, run Cat5 from the controller to the 1st fixture with a wall box at each end. Then run DMX cables using stranded core cable between each fixture.

 

Run Cat5 between every major point where there are lights. If there is more than 1 light in 1 place. Put a DMX in plate at one end of the set and a DMX out at the other then daisy chain from there.

 

That way, you minimise the number of Cat5 cables you have to run and terminate and you still have done the job properly.

 

Josh

 

A concurrent post has been automatically merged from this point on.

 

Cable wise I've seen this: http://www.vdctrading.com/products.asp?SubSectionID=5 used (and terminated quite a lot of it my self one way and another) quite a bit and it seems good.

I have used that stuff and while it is good, it is expensive.

 

Having just received a drum of DMX-P-01 found on this page from Belcom, I can vouch for it's quality and most importantly, how easy it is to solder. It is a stranded core cable and can be connected directly to the fixtures.

 

Another product in the range is DMX-01 This is similar to DMX-P-01 but not as hard wearing, this shouldn't be a problem for your purposes and is still stranded saving you the money on Wall boxes.

 

Josh