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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => Lighting FUD Forum Archive => Topic started by: Tony Mah on April 20, 2004, 02:28:57 am

Title: How to make a 5 pin DMX cable?
Post by: Tony Mah on April 20, 2004, 02:28:57 am
Do I use star-quad cabling?

Tony
Title: Re: How to make a 5 pin DMX cable?
Post by: TJ (Tom) Cornish on April 20, 2004, 11:55:39 am
You haven't said a lot about your application.  Do you know if your equipment requires both pairs?  Do you need 3 pin or 5 pin jacks?  How far are you running?  Is this installation or portable?

DMX technically is supposed to run over two-pair shielded cable with an impedance of 110ohms.  If you are doing an install or have a long run, it's worth your time to do it right and find cable with these properties.  You can find many such cables by doing a google search "bulk DMX cable".

If you just have a couple of dimmers and a portable system, regular mic cable will probably work fine as long as it is terminated correctly and you have the right adaptors.  People have had some success even running it down the audio snake, although this could potentially cause audio interference.
Title: Re: How to make a 5 pin DMX cable?
Post by: Alex_C on April 20, 2004, 04:33:10 pm
Pin 1: Ground - connect this to the shielding on the cable but *not* to the case of the DMX plug itself.
Pin 2: Cold
Pin 3: Hot
Pin 4/5: Not Used (Normally)

There isn't a lot of equipment that requires the second pair.

As TJ already stated, it's worth getting "the right stuff" for longer runs. I have to admit that I have a selection of 5->3 pin adaptors so DMX can be run down short audio lines in emergencies.

If you do need that second pair, the wiring is dependent on the application. Avolites Pearl 200X, for example, uses pins 4/5 for a second DMX universe on the same connector - which then needs splitting out. I find CAT.5 STP cable (shielded Ethernet cable) is good for DMX.

Alex