Most lighting control boards put out an output of information, that is called DMX-512. The reason for that acronym is that it is digitally multiplexed information or (protocal) and can control up to 512 items such as channels of dimming, color scrollers, strobes and functions of moving light instruments. Because the information is sent down one set of twisted wires in a serial fashion, the receiving device (
dimmer) must know which set of digital information out of the 512 that the lighting controller is to control.
Example, you want the 3rd
fader on a controller to operate the first
dimmer output on a four pack
dimmer. You have the choice of setting the 3rd
fader to control any of the 512 outputs. That is addressed in the control board in what is refered to as "
softpatch". The
dimmer channel that the control board sends out with that 3rd
fader info now must be addressed in the
dimmer pack.
Many of the lesser expensive
dimmer control boards may not have
softpatch and if that is the case then the 3rd
fader would be outputed as
DMX 3. The
dimmer pack is then addressed to start at
dmx 3 and the first
channel on the
dimmer pack is then controlled by
fader 3.
Dimmer packs are usually addressed for the starting
dmx number and then the remaining dimmers in the pack will follow sequentially in order. The
address is usually set
in one of two ways. The most convenient is to have a
LCD display and some up and down buttons. by pressing the buttons, you can
advance or decrease the
dmx starting number. A less convenient and generally more popular method is a set of DIP switches. This is a series of 9 or more small switches that either slide or rocker to either on or off position. The value of each
switch follows a
binary math
system. The first
switch to the left has a value of "1" each sequencially following
switch doubles the value of the previous one. such as 1 then 2 then 4 and so on until the 9th
switch has a value of 256. You set the
address by adding the value of all the switches that are in the on position. This isn't quite true
binary as
binary counts from right to left and most all of these
address switches count up from left to right, but through popular acceptance and the commercial numbering that was already a part of DIP switches, everybody except the very fussy pureists accept it. By the way the term
DIP switch comes from the fact that the
switch assembly mounts the same as integrated circuits that have a dual inline
profile, or package. In other words DIP. One caution about
DIP switch addressing. Some manufactures use all the switches off to be
address "one", if this is the case, the
address switches will need to be set to one number less than the
address you desire.
Some manufactures use the all off position for special purposes and some use the all off and the 1 value only
address as
address "1". If there are more than 9 switches, then the remaining switches are specific to a manufacture, as to what they do. Many of the lesser expensive packs use the tenth
switch to determine if the pack is
DMX addressed or an internal program. Some use it to deternine if the pack is slave to another pack. some of the
scroller manufactures use it to control the fan speed and others use it to determine the maximum speed of changing colors.
Everything that I have written is assuming
DMX control. Before
DMX, their were many different addressing systems and one of those is still used on some of the lower end American company items. It is generally refered to as
Microplex and was developed out of two or three earlier systems. While there are at least a dozen folks that will follow and disagree with me,
DMX 512 and
Microplex are about the only systems used today. There are a couple of systems that use Net nodes and or two way communicating systems, but these are still based on
DMX, only a different way of communicating that info.