What is a Universe?
Let’s go meta.
What if there wasn’t just one universe? What if there was a multiverse? What if in this universe I taught theatre, but in another universe I was a professional swimmer? I swam when I was a kid. As the teacher, I have no concept of my swimmer self. I can’t see him. I can’t touch him. And I certainly can’t speak for him. But both of us are named Drew. But what if there was someone looking over both universes, able to see both versions of me and talk to us individually?!
Lighting networks can have multiple DMX universes and can talk to fixtures in both individually. And I guess the multiverse analogy really doesn’t stand up after this point. Or at any point. So we can’t talk about Max Tegmark’s four levels of the multiverse or Brian Green’s nine types. Bummer. But in lighting, we have these things called universes. And you can have multiple of them. So … I guess I had to go there. Sorry.
Think of it more like this. Pretend we have two different universities. At one university, the U of A, the student with ID number 7 is Philip McFakerson. At another university, the U of B, the student with ID number 7, the same ID number, is Riley Ruse. If you’re working with both universities, you need a way to differentiate Philip from Riley.
Why would you need that in lighting? Well DMX only allows for 512 addresses. That’s how many 1s and 0s that can be transferred together in a packet of information. So then what happens when you need more than 512 addresses (which is really quite common when using several moving lights)? Well, then we move to a new universe of DMX, a new set of 512 addresses.
But the light board needs a way to address each universe differently. Just like we need a way to refer to the students from the U of A and the U of B individually. So … the second universe doesn’t use addresses 1 through 512, it uses address 513 through 1024; a second set of 512 addresses.
So how does this work practically?
In universe 1, address 7 is referred to as address 7.
In universe 2, address 7 is referred to as address 519. (512 + 7). The fixture is still addressed as address 7, but the light board calls it 519.
Confusing? Yeah! But don’t worry, the light board actually has ways to help make it easier for you.