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I'm running some permanent wires for DMX control in the small theatre in our facility, and we have a box of this cable left over from a different job.

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I've read a lot about how you shouldn't mix wires with DMX because improper impedance's can mess with your signal.

Is this cable suitable for DMX control?

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DMX needs a cable with 110 Ohms impedance, and it should be twisted. I was not able to see the impedance of your proposed cable in the datasheet, but I doubt that it is 110 Ohms.

Another thing is that this cable has only 2 conductors, that means the shield/screen has to be used as the GND connector. This is not good in terms of electromagnetic compatibility.

So it all depends on the performance criteria that you need: I would expect the DMX bus to work with this cable, but as there are a lot of signal reflections because of the improper impedance, I would definitely not recommend using this in a professional setup.

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  • \$\begingroup\$ That looks to be 600 ohm audio cable, and not STP either. \$\endgroup\$ – Sparky256 May 28 '18 at 6:20
  • \$\begingroup\$ Is it the twists in the cable that give it the proper impedance? Could you compensate for the impedance using a resistor at one end? \$\endgroup\$ – ShemSeger May 28 '18 at 15:33
  • \$\begingroup\$ No, the impedance of the cable is defined by the capacitance and inductance of the wires. Its a property of the cable and cannot be compensated with a resistor at the end. Sorry... \$\endgroup\$ – Stefan Wyss May 28 '18 at 15:37

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