DMX Checklist

Troubleshooting your DMX set-up.

If a DMX problem arises, the solution is sometimes a simple overlooked item. Please look over the general checklist below before submitting a Field Service Support Request.

Are you using the proper Cabling/Wiring?

To ensure proper signal strength, 120-OHM shielded twisted-pair or Cat-5 to Cat-6 UTP cables are required. A big mistake often made is the use of improper cables which are not made from twisted pairs.

Are you using the proper Topology?

Daisy-chain is the proper method of connecting DMX fixtures (which includes dimmers and fixtures). With each fixture having an input and output, consider the signal as going straight-through from fixture-to- fixture. With the use of a DMX splitter, you can branch the daisy-chain, otherwise there will be electrical reflections and issues within the set-up.

Use proper DMX splitters when needed.

If you need to go in multiple directions, use a quality DMX splitter. Without the use of a DMX splitter your signal will be weak to any branches on your topology. Remember to properly terminate your run.

Limit the number of devices on your DMX run.

The DMX standard for a single DMX run is 32 fixtures. The use of more than 32 fixtures will require a DMX splitter to increase your run capacity. Even with the use of low-load fixtures it’s safer to stay with in the DMX standard of 32 fixtures per run if you are not using DMX splitters.

Limit the length of your wiring.

Our recommendation for wiring distance is an approximate length of 800 feet to the last fixture per run. The use of a DMX splitter will be required for longer runs.

Properly Terminate the last fixture on your DMX run.

Every DMX run should be properly terminated with a single 120-OHM resistor.  A DMX signal that reaches the end of the lighting run that isn’t terminated can bounce the signal back causing interference and result to flickering lights and loss of control. If adding the terminator makes the DMX fail, then it is most likely a cable or connector issue.

Unplugging and adding fixtures back to the run.

Unplug fixtures and individually add them back to the run until the problem is identified. Check for a bad ground or ground-loop caused by a single fixture.

Use a DMX Tester.

Use a DMX tester to analyze the signal at the far end of every DMX run. We recommend DMXcat for RDM addressing, monitoring, and testing.

Check your cables and connectors.

Check all DMX cables for cracks or breaks, including any solder joints. Also check connectors and terminators for cracks or a loose fit.

Check sources of electrical noise.

Keep unshielded cables clear from electrical motors or equipment that can create electrical noise or interrupt the DMX signal.

Is there a bad fixture?

Check your fixtures. It is possible for a damaged fixture to introduce noise or a bad signal into the DMX run. Try temporarily removing a fixture out of your DMX chain to see if problems disappear.


After checking all the possible solutions above, If you still need additional troubleshooting support with your Insight Lighting product, please fill-out our Field Service Request form.



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Insight Lighting Cable Guide

Remote Device Management (RDM) is an enhancement of DMX that allows bi-directional control and feedback from lighting fixtures and devices. Combined you get a robust and reliable system for lighting control. Contact us for ordering information.

Connectorized Cable Guide

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Digital Multiplex (DMX) allows bi-directional control and feedback from lighting fixtures and devices. It is a robust and reliable system for lighting control. However, without the proper cables and connectors, problems can arise such as random flashing of lights, erratic operation and delays in responding to commands. The following is a cable guide of our cables, connectors and terminators for proper and seamless connections with our lighting system. Contact us for ordering information.