DMX Address

This is a simple guide to setting DMX addresses on your fixtures so that they can communicate between the lighting desk and each other. 

To start with let’s use a simple set up of four PAR 64 LED fixtures that we want to control individually from a standard DMX lighting desk.

Once we have connected all the fixtures to the power available on site, we need to daisy chain the fixtures together using DMX or XLR cabling. By daisy chain we mean that each fixture has an in and out for the DMX signal so that each fixture does not need to be individually connected to the controller.  It is worth bearing in mind that when you have large chains of fixtures it is essential to use a DMX terminator in the “DMX out” on the last fixture in the chain. DMX terminators are generally just a male XLR connector with a 120 Ohm resistor soldered between pins 2 and 3. 

Now we have the fixtures connected to each other and one of the fixtures connected to the controller we can now decide which one of the 512 DMX channels available we want to control our first fixture. This is done using the DMX Dip Switches; they can normally be located near the DMX Input and Output sockets. Generally there will be 10 DIP switches for setting the DMX address, these are set using binary. Each switch has a corresponding value, and the DMX address is calculated by adding together these values.

The numbers on the DIP switches correspond to the following values:

SWITCH VALUE 

1 : 1 

2 : 2 

3 : 4 

4 : 8 

5 : 16 

6 : 32 

7 : 64 

8 : 128 

9 : 256 

10 : N/A

Switch 10 is most commonly used to set which mode the fixture operates in, either DMX or stand alone mode. Obviously for this purpose we want the fixtures on DMX mode so make sure switch 10 is set to the on position on each light. 

The Par 64 fixtures we are using in this example use 4 DMX channels: 

Channel 1: Red output

Channel 2: Green output

Channel 3: Blue output

Channel 4: Master output

So, we want the first fixture to be on channel 1. This means we use switch 1, which has a binary value of 1 and switch 10 to let the fixture know we want it to be in DMX mode. This fixture will now respond on faders 1 - 4 on our lighting desk. 

The next fixture will need to start on channel 5 as the first 4 have been used by the first fixture. To make a binary number of 5 we need switches 3 (value of 4) and 1 (value of 1) set to the on position, again along with switch 10 to set the fixture to DMX mode. The next fixture will need to be on channel 9 as channels 5 – 8 are being used by the second fixture. To do this we need switches 4 and 1 set to the on position (values 8 + 1).

The last fixture will need to be set to channel 13 (switches 1, 3 and 4). These switches have the corresponding values of 1 + 4 + 8 = 13.

This is everything we need to set to allow individual control of each fixture; obviously we can create groups of lights that respond to the same faders on the desk by simply duplicating their DMX settings and channel numbers.