What if you need to do more than dim a resistive incandescent light in your DMX control chain? What if you need to provide an on/off function? Just like the K8039 dimmer, if you are switching a device that doesn"t have a standard DMX control input, you"re pretty much out of luck... unless you have this handy little relay board! Here"s how it works: First we plug this relay board into the DMX control daisy-chain (or directly to a controller if that"s all you"re controlling). Next, set the dip switches to the desired DMX address. There can be up to 512 addresses in a single DMX chain, so you"ve got plenty of room to add more devices later! Finally, map that address in your controller, and you"re now "talking" to the relay switch with the controller, and can enable the on/off function of the relay. It"s that simple! The switch is actually a bus-controlled power driver. The on-board relay will be activated when the DMX value of the set channel equals 140 or more, and will shut off when the value is 120 or less. LED indication is provided on the board for power supply and DMX error detection. In addition, "Safe DMX Data Stream" mode is used to reduce interference. If the DMX signal is lost (i.e. somebody trips on the cable!) the "Relay Hold" function will continue to latch the relay. DMX input is via a standard XLR connector. Relay switching capacity is 8A. The board runs on any 12VDC unregulated power supply or source. Available as a do-it-yourself kit or factory assembled & tested for immediate use. Board measures 4.1" x 2.4" x 1.2" From Velleman.