DMX lighting is a type of digital lighting control. DMX stands for Digital Multiplex and is a system that allows multiple fixtures to be affected by a single controller. DMX lighting uses a data signal to precisely control the intensity, colour, and other parameters of LED lights. That makes DMX-controlled lighting versatile. You can create any look you want and be entirely in control of your lighting.
Table of Contents
1. DIFFERENT TYPES OF DMX
DMX512 is the most common DMX protocol. DMX512 uses a data signal to control lights. The data signal is sent over a cable from the DMX controller to the DMX fixtures. The standard cables type used in a DMX network are 3pin or 5 pin cables. Do not use XLR3 or XLR5 cables, because those are audio cables, and not DMX cables.
With DMX512 you can control 512 channels, which each can perform a maximum of 256 functions (0-255). With DMX fixtures, you can create your own DMX-Universe, which you can program to your requirements.
1.2. WIRELESS DMX
Wireless, it is as easy as it sounds. It means without cables/wires. If it is hard to wire every device, it is easier to send a signal through the air. This control method is commonly chosen in situations where the track is already installed, but without DMX512, and you want to use DMX as a control method. Wireless DMX is in those cases the faster and cheaper option. It is also easy to use in for example churches, or other places where new cabling, or cabling at all is not desired, to maintain the appearance of the location. There are risks, for example in locations where a lot of signals are in the air, the DMX signal cannot come through clearly and fixtures might not listen to the signal as well as they would when wired.
1.3. Difference casambi and wireless dmx
While both systems work with a wireless data signal, there is a difference between both systems.
- You need to be in reach of the fixture you want to control
- Sends signal to all devices in the DMX-Universe, but only the one with the channel that corresponds with your data output listens
- W-DMX dims more gradual than Casambi, which is useful for application in theaters and movie theaters
- You only need to be in reach of the first fixture to adjust one, because they ‘talk’ to each other
- All devices listen to a command
2. POSSIBLE APPLICATIONS FOR DMX
The versatility of DMX lighting allows it to be beneficial for a wide range of applications. Among the most common applications are theatres, concerts, clubs, churches and schools. However, you can also use DMX in museums, retail stores, TV studios, and hotels. The possibilities are endless. The main advantage of DMX-controlled lighting is that it offers complete control. You can program LED lights to create any desired effect. You can control the intensity, colour, and other parameters within a split-second.
3. DIFFERENCE BETWEEN CHANNELS AND ADDRESSES
Your DMX-Universe has 512 channels, you can program your fixtures or devices on any of these channels. Each DMX channel controls a single parameter of the fixture. For example, channel 1 controls the colour red, while channel 2 controls the colour green, on fixtures with RGBW or RGBA coloured LEDs. DMX fixtures need multiple channels, which you can control in multiple ways to program the fixture to show the desired result. A DMX controller generally has several sliders(faders) that control the corresponding channel from a fixed starting address, which is the first channel of a fixture.
When you program a fixture on a channel, it becomes the starting address for that fixture. When you want to alter the output of the fixture, for example you do not want it to shine red light anymore, but blue light, you need to know what the starting address for the fixture is, to adjust the right faders.
4. HOW ADDRESSES WORK
> 4.1. Number of addresses needed for a fixture
Every fixure has its own number of channels needed to be able to use every function. When you start programming all of your fixtures, check the amount of channels needed when you add more than 1 fixture to your Universe, because if you address your fixtures immediately after each other, it is possible to adjust the settings on fixture 1 when you want to adjust the settings on fixture 2.
Example: You have 4 fixtures. Fixture 1 has 4 colours, RGBA. Fixture 2 has 4 colours, RGBW. Fixture 3 has 3 colours, AWB. Fixture 4 has 1 colour, W.
When you’re going to calculate which address to program, to be able to use every function, you need to look at the amount of channels.
Fixture 1 needs 4 channels. Programming usually starts on address 1, so you program it on address 1.
Fixture 2 needs 4 channels, but fixture 1 also needed 4. To make every function of fixture 1 work by only altering the designated colour, you cannot program it on a channel it is using, so you need to start after those. Of course, you can program them directly after one another, but the result will not be as nice to see. If you programmed fixture 2 on channel 2, you would alter the green colour on fixture 1, and the red colour on fixture 2 simultaneously. That is why it is commonly chosen to program fixture 2 on address 5. Because it has 4 functions, it gets channel 5-8.
Fixture 3 needs 3 channels, so it gets addressed on channel 9, and needs channel 9-11 for its colours.
Fixture 4 gets channel 12.
If you want to add more fixtures to your DMX-Universe, you need to program it on address 13, to be able to use every function of device 4.
4.2. How to bundle fixtures
To make it easier to control multiple fixtures at the same time, you can program them on the same channel. When you alter the settings for a fixture, all fixtures on the same address listen to your commands. This way you only need the amount of channels the fixture needs once, so for example with 2 fixtures that both need 4 channels, you only need 4 to control both of them, instead of 8.
4.3. how functions work 1-255
Each channel, from 1-512, can adjust a parameter with a data-value between 0 and 255. These are 256 steps. It does this with an 8-bit ‘word’ of 8 digits, made of the numbers 0 and 1. Some parameters you can adjust with a function are the brightnesslevel, colour, rotation or strobe. The higher the value between 0 and 255, the more intense the function becomes. An example, when you want to adjust the brightnesslevel of a fixture, 0 means off, 255 means shine at full capacity.
If the data-values 0-255 are not accurate enough for the fixture, for example, when you rotate a fixture the rotation goes very jerky, some devices also support a 16-bit mode. That mode uses 2 channels. 1 for coarse adjustment and 1 for fine adjustment. With the coarse adjustment you have a value between 0 and 255 and with the fine adjustment another value of 0-255 for the chosen value with the coarse adjustment. This allows you to let a fixture shine a beam of light, or rotate, in a very focused way. You can do this by using 2 channels for a function such as Pan or Tilt. This means that your Universe no longer has 512 channels, but 256, because you use double the amount of channels per function, if you do this for every fixture or device.
> Programming after another
> Programming in bundles
5.1. DIFFERENT KIND OF SPITTERS
There are many names for splitters, but you can call it a splitter, when it isolates the output from each other, and the computer/console, and copies the DMX signal.
Maybe you know them, the Y-shaped cables, which make it easy to extend your universe, without having to lay a new cable. To make your Universe work the best, we highly recommend, do not use these. You send a high frequency signal through the DMX cables. This signal rapidly declines when you use a Y-cord and after a few metres it is gone.
5.3. WHEN ARE SPLITTERS USEFULL?
Disconnected devices On sensitive area’s, where a lot of people walk around or on the DMX cables it is possible one gets disconnected. When that happens and you’ve used a splitter, not all of your devices turn off. When you have not used a splitter, every fixture after the one that gets disconnected loses signal, and the ones before can flicker, because there is no ‘end'(terminator), so the signal goes into nothing and can bounce back.
Multiple lighting positions on a stage When you have multiple lighting positions on a stage it will most likely be easiest to use a splitter. If these positions have some distance in between them, you’ll have to bridge quite a distance. This might be bad for the DMX signal, plus it can be hard to neatly store away the cable(s). The maximum length recommended for a DMX cable is 300 metres.
The daisy chain is longer than 20 devices The recommended amount of devices for one daisy chain is 16 to 20. If you’re exceeding this limit, it is better to use a splitter, so your signal stays strong, and your fixtures work the best.
5.4 WHEN ARE SPLITTERS NOT USEFULL?
If the devices you put into your Universe need a lot of channels, so you can only put a few devices in a chain before the channels run out, you do not need to use a splitter. That is because you require another controller for the remaining devices in your Universe.
Another example is if your Universe is small. If you have, say, 10 lights in a chain, you do not need a splitter necessarily.
6. DMX TERMINATOR
For the same reason you shouldn’t use Y-shaped splitters, you should use terminators on your last device. To prevent unintended brightness levels, flickering and flashing of lights, and unstable operation, because of a ‘shadow signal’ that bounces back through the normally 1-way DMX data cable. You can terminate the signal with a 120 Ohm resistor.
7. DMX SIGNAL REPEATERS
When your DMX signal has a lot of cable to go through before it reaches your last fixtures in your daisy-chain, a dmx signal repeater can be usefull. A signal repeater amplifies the DMX signal, so all of your fixtures receive the same strong signal, and no data is lost at the end. You can compare a DMX signal with a scream. When you scream, the noise you make is loud when it comes out of your mouth, but loses strength the further the sound goes. A DMX signal is strongest when it leaves the controller, but can lose strength when it has to go through a lot of cable.