What is DMX Polarity and Why Do I Care?

Many entry level DMX consoles, such as the Chauvet Obey 40 and 70, have a curious little switch that is labeled “DMX Polarity” on the rear panel where you hook up your lights.

If you’ve accidently pressed this switch, you probably know that it doesn’t help your lighting rig to work correctly…most of the time!

Here’s how it works:

Find yourself in a situation where you need to switch the DMX polarity?

Unless you’ve run into some old Martin lights, this probably means that something is wired wrong.

While the polarity switch will help you when everything is wired wrong, you’re up a creek if only some of the lighting rig you are using is wired wrong.  If it’s a portable set up and you’ve got access to all the cables, you can simply troubleshoot by figuring out where the data stops – that’s your bad cable and you can now fix it.

However, if you don’t have access to both ends of the cable, but need to fix the DMX polarity, it’a time to break out the toolkit.

Here’s a great explanation on how to fix bad DMX polarity by switching pins 2 and 3:

While problems with DMX polarity aren’t as common as other DMX problems, they still can stop your lighting from working when they do occur!  Use this guide, and check out the rest of the posts here on Learn Stage Lighting to keep your lighting rig working in tip-top shape!

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