What is an Address?
Alright. This concept can be a little confusing, but try and track with me.
An address is an ID for a light, the ID that a light board uses to address a fixture.
Each dimmer would have its own ID, or address.
A moving light would have an ID, or address.
A rotating gobo would have an ID, or address.
Everything needs to be ID-ed, addressed.
So, if a dimmer is ID-ed to address number 11, turning address 11 to 100% on the light board will make the dimmer pump out full voltage.
In a moving light, an address might reference how far the light should tilt.
In a rotating gobo, the address might tell the accessory how fast it should spin.
An address could refer to many different parameters, it all depends on the fixture; who says, “Here is my address! Control me!”
Now. What if two items have the same ID or address? The light board doesn’t care, so they’ll both respond because they both have the same ID. This could be a problem when you want to control lights individually. Or, this could be advantageous when you want a number of lights to do the exact same thing, if you want them to respond identically. Benificial or annoying, know that fixtures with the exact same address will all respond to the same address.
Finally, some fixtures don’t have just one address, unlike a dimmer which only does one thing. Some fixtures need multiple addresses to function properly.
For example, a color changing LED might want to control its output of Red, Green, and Blue lights individually. On this fixture, its address is then actually what we call a “starting address”, or the first address it needs. It will then utilize the next two addresses as well, three in all, Red, Green, Blue. A starting address of 21 would mean that Red is controlled by 21, Green by 22, and Blue by 23.
This is really important because if you addressed your next LED light at 22, the addresses used are going to overlap. Your new fixture will use 22, 23, and 24. So when we turn up address 23, it will control the Green value of the first light, and the Red value of the second.
Therefore, it’s very important to know the footprint of your fixtures. Some need 1 address, others need 2, 3, 5, 7, 9, or even 20.
In our LED example, the footprint is 3 addresses. So the next fixture should really have a starting address of 24 to avoid any overlap.
If you’re unsure how your equipment works, consult your fixture’s user manual. The ETC EOS light board will keep you from overlapping as well as map out all the parameters, which is really convenient, but it’s annoying to find out you made a mistake after you’ve addressed and hung all your lights.