When I assign a DMX channel to a dimmer, the dimmer comes on and stays on. Why can’t I dim it?

This is the most common technical support call we get. (In fact, for weeks at a time it’s the ONLY call we get!)

There is another channel up in your system.  You may not be aware of it or know what it is, but it’s there and it’s a lower DMX channel number than the one you want to assign to the dimmer.  When you press the Set button on the dimmer, it finds the lowest DMX channel that is not off. Your dimmer found one, but it’s not the one you have in mind.

Common causes of this, in order of likelihood:

1. House lights. We have seen many installations where house lights are assigned to a low channel, like DMX channel 1.  And you have your house lights up while you’re assigning channels to your RC4Magic dimmers.
2. Work lights.  Same idea… your work lights are on, and they’re using a low DMX channel.
3. A complex fixture profile sets some channels to something other than zero. In this case, when you clear your console and all channels are “off”, channels controlling moving-light motion axes, for example, might be at 50% to park the light at home position.  You need all channels to be actual zero.  Not home for your moving fixtures.  Not the middle of a scroller gel.

How to find the problem:

The best way is to use a DMX data tester, like a Goddard Design DMXter, or a Fleenor Gizmo.  Connect it right at your RC4Magic DMXio transmitter.  Look at the channel levels.  Find the first one that is not zero.

How to work around the problem:

Use an alternate source of DMX data to configure your RC4Magic dimmers.  It may be an arduous task to figure out how to get your expensive and complex lighting console to actually clear all DMX channels.  Instead, grab a Pocket Console or DMXter and use that.

It doesn’t matter what your data source is when you assign channels to dimmers.  Channel 452 on your DMXter is the same as channel 452 in a universe of your console.  The dimmer remembers your settings forever until you change them, so you can move your transmitter back to your lighting console and it won’t matter at all if other channels are up.  It’s only a problem at the moment you need to press the Set button.

Is this hassle really worth it?!?!

Well… yeah.  : )

Other DMX products provide dipswitches, or rotary controls, or a display and up/down buttons.  Any of these options take up more space than the size of our entire DMX2dim 2-channel dimmer.  You love the size of our little units.  But now you have to figure out how to get one DMX channel on at a time.  Only when you’re setting things up.  Then you’re done.

Now that we’re in the age of Remote Device Management (RDM), settings could be done that way, with no switches on the dimmer at all.  But you’ll need an RDM controller.  Do you have one yet?  Most of our customers do not.  In a few years you will.  We’ll be ready for you when you do.  Have a look at our RC4Magic CS1 Control Surface — it’s a small DMX console with built-in wireless and RDM controller features coming soon.)

RC4Commander is an easy-to-use USB dongle and Mac or Windows program that lets you access features and functions in your RC4Magic devices on your PC screen.  Power up a dimmer, read its settings, change them, send them back.  This also lets you see which DMX channel was up when you pressed the Set button.  That’s kinda handy, don’t you think?  Call us for more information.