As a lighting technician, sometimes you need to know how healthy your dmx connections are among the fixtures. Sometimes, due to the wires, fixtures themselves or voltage fluctuations, the DMX system is exposed to many problems and errors. So I made this instructable to show you if you are receiving a DMX signal in a determinate point of your system connections. It is no thing special but it is quite hard to find the diagrams and the info to make it.
We only need a few components:
For the Terminator:
- XLR male connector (3 or 5 pin)
1x - 120 ohm resistor
1x - Red (or whatever color you want) LED
For the Terminator & Tester:
- XLR male connector (3 or 5 pin)
2x - 270 ohm resistors (Or whatever between 220 and 280 ohms)
1x -Green LED
1x -Red LED
(Or you can put a single LED if it is a bi-color one)
Tools and materials:
- Soldering iron and solder
- A cutting nipper or a pair of scissors
- A little piece of wire
- A little piece of wire cover
- Small tweezers and a bunch of patience
DMX Terminator
What we need to do is very simple. As shown in the diagram, we will connect the 120 ohm resistor between the XLR pin 3 and the catode of the LED, and the anode to the XLR pin 2. Since in the XLR5 pins are a little bit smaller, be patient to get your best work. Use a little bit of wire to make the LED longer, and when you have finished, cut a little bit of wire cover to isolate the conections. That's all, when you have finished, it's 100% functional and you can go to the last fixture in a DMX line and put the terminator on it. Bye bye fluctuations.
DMX Tester & Terminator
If you want to be a perfect freaky guy and you want to look like a magician to your partners and friends, you need to make your own tester and terminator in a single XLR connector, with a pair of LEDs blinking and saying you are a real professional, a doctor of the DMX lines!
Specially if you choose the 5 pin XLR option, I tell you, you are insane, you are the crazy guy that doesn't care about spending time burning your hands soldering. You need the second diagram!
Put a 270 ohm resistor between the XLR pins 2 and 3. Take the other resistor and connect one side to the pin 2 and the other side to the anode of one LED and the catode of the other one. Then, return the LEDs to the pin 3.
Connecting our new tool to a DMX source we can see if it is working properly. In the terminator device, only you can see the Red LED shining, so it is correct. In the tester and terminator device, you can see both LEDs shining (one fixed and the other blinking a little bit) but if you only see one of them shining, don't worry, check the connections inside, or be sure that you are sending a DMX signal to it. Take a look at the photos, when the tester is connected to a DMX output but with no data being sent, only the green LED is turned on. At the very moment the DMX signal is being sent, both of the LEDs will shine.
I've been trying and using this devices for months and they are pretty good for DMX lines. Sometimes a little device is our best friend! And of course, if we make them ourselves we can learn and save a little money.
Good luck and thanks for reading!