DMX Cables - 5pin XLR... only 3 wires?!?

[Zach Love]

Anyone know about DMX cables? (The 5pin XLR cables used for controlling lights.)

I use a Datavideo switcher (HS-2000) that uses those cables for the headsets / tally.

We ordered a few Hosa 5 pin XLR cables from B&H, but they only have 3 wires in them. (See attached photo.)

Obviously they don't work with the switcher as the switcher needs 5 wires for the headsets / tally. At a shoot with long cable runs I borrowed a DMX cable on a multi cam shoot from an AV / lighting tech & everything worked perfectly.

This seems like they're bad cables. Unless, does DMX use a 5 pin connector, but only 3 wires? It doesn't seem to make sense that you'd have empty pins with no wires connected to them.

[Zach Love]

Just following up in case anyone else stumbles across this post.

So the official spec of DMX cables is that they only use pins 1-3 & that pins 4 & 5 don't do anything. So some manufactures use 3 wire cable to save on costs (or make more profit). Higher quality cables use 5 wire cable (or two sets of pairs & a shielding) mostly in case pins 4 & 5 get used for something down the line.

It seems like the reasoning for using 5 pin connectors when DMX only needs 3 of them, is that the designers didn't want lighting cables to get confused with audio cables. That being said, there are people that use 3 pin XLR cables, the same ones used for audio, as their DMX cables, because you only need 3 wires for the functions of DMX.

So now, for my office, we just need to find some DMX cables that have 5 wires & something soldered to all of the pins. Once we find that, we'll have some extra cables for headsets & tally lights.

[Shaun Roemich]

Good catch, Zach.

I had been looking at a similar setup with the Datavideo comm system last year and was looking at DMX cables as a possibility.

Then I "got wise" and said if I want comms, I'll just buy ClearCom or Telex and quit playing with toys. Especially after wasting 3 days emailing back and forth with Datavideo support about their 12v capabilities over the multi-cable...

[Daniel Epstein]

Not too surprising. Similar to many connectors with more than 2 wires used. 4 pin power XLR only uses 2 out of 4 pins. As you mentioned..One of the reasons they use extra pins is to prevent you from plugging into a cord that is plugged into something other than DMX. If they used a 3 pin XLR you might plug into the audio board and cause problems you weren't expecting.

[Paul Cox]

Hi there , You can use any XLR Microphone cable as a dmx cable providng the dmx device only has the standard 3 pin connection obviously , but my point is you do not need the extra 2 pins or wires, I run a light show with 36 fixtures all dmx chained to gather with microphone cables, some of the lights are 8 channel lights and I have never had a hiccup, hope that helps

Paul

[Shaun Roemich]

Paul, you missed the point. The Datavideo intercom system the OP was hoping to extend is a 5-wire XLR system with the same XLR ends as a DMX but requires 5 wires.