Introduction to DMX 512A
DMX512A is a Communications Protocol that was developed in 1998 to allow the Multiplexing of 512 control channels on a pair of shieled wires, using RS485 serial transmission. A group of 512 channels is called a Universe.
Initially DMX512A was developed for Dimmers where one DMX 512A channel controlled one Dimmer Channel and the conventional lights that were plugged into it. Initially a DMX512A channel has 8 control bits, which provide 254 voltage increments that the dimmer converts into a 0 to 100% brightness control.
The disadvantage of 8 bit control resolution is that many LED fixtures have visible Steps of brightness at lower output levels. To overcome this, manufacturers use 16 bits of resolution, which uses two consecutive control channels.
Early LED Fixtures had separate Red, Green and Blue light emitters, with one channel of DMX512A used for each colour. Later design LED Fixtures added extra coloured emitters which are mounted on the same package, usually referred as an All-In-One LED. Each colour needs a separate control channel, with newer design using 16 bit resolution or two control channels to provide more accurate resolution of colours.
CAUTION – LED Fixtures have to be supplied with a stable power supply. Connecting an LED Fixture to a Dimmer Circuit will result in damage to the LED Fixture Electronics.
Some installations use Power Switching Systems that detect the prescence of a DMX512 signal from the Control Desk or Computer and switch on the power to the LED power sockets i the lighting rig. They may also switch off the power after a preset time, after the DMX control signal is switched off.
Types of LED Fixtures
All LED Fixtures have basic Parts
Outer Casing Usually aluminium but can be plastic. This usually has Power inlets and power outlets, DMX inputs and Outputs on it.
Mounting Yoke to allow the fixture to sit on the stage or be rigged, usually to a lighting bar.
Power Supply – Usually Universal 110v ac to 240v ac 50 to 60 hertz input, to be converted with a Switch Mode Power Supply to provide the supply voltages for the internal parts.
Display Board – has seven segment LED displays with push buttons, or LCD display which may be a touch screen, that allows you to set the DMX Address and Fixture Mode.
Control Circuit Board – Receives DMX512 signal, processes it in a microcontroller depending on the Mode and Address that has been set in the Menu, then controls the amount of output from the LED Driver Circuits to vary the Intensity of the LED Emitters.
LED PAR Light
These lighting fixtures have evolved from the early low wattage single colour 10mm LED emitters
To the 1W power Tri RGB and Quad RGBW for drama or RGBA for music all-in-1 LED emitters.
To the higher power 20W typical 4in1 or 5in1 or 6in1 (RGBWAUV) being among the more common versions.
LED WALL WASHER
LED Wall Washers have multiple rows of all – in – one LED emitters. They were designed for architectural lights, but can be used as LED Sidelights when rigged vertically or used as an overhead colour wash.
LED BARS
LED bars being used as footlights at Dolphin Theatre with offset brackets for low profile.
Understanding LED Fixtures Manuals
Rigging and Patching LED Fixtures
Controlling LED Fixtures
Zero 88 FLX S24 RRP $4,999 & FLX S 48 RRP $6500 ( lower prices available) are fader based desks from Zero88 that use the same ZEROS operating system as most other Zero88 desks. They have 2 pages of faders that are Channel or Playback faders.
The internal 7″ touch screen can display Groups to give the operator the equivalent of the third row of Group faders on the legacy desks.
The FLX S48 has a DVI-D output and USB port to allow the use an external 24 inch touch screen monitor such as a Dell P2418HT 24 inch Touch IPS LED Monitor for $449 to provide easy access to the Colour, Beam, Shape, Position, Effect palettes.
They have four encoder wheels for moving lights, the ability to set up a remote tablet or smartphone as a remote screen or riggers remote. They come with one universe and can be expanded to two universes. They do not have built in colour swatch books but can import swatch book equivilant images using the image picker function.They have the Lee Mood Boards installed and can do command line entry for advanced operators.
The FLX S24 is ideal for small schools as one page of 24 channels can be single channel dimmers and the second page of 24 channels can be LED’s or movers.
FLX S https://zero88.com/control/flxs
If a school is updating to LED’s and has several dimmer racks, a FLX S48 is a better choice as the extra faders provides quicker access to lights without having to changes pages all of the time.
For more details and videos go to https://zero88.com/control/flxs
Page created 15 March 2026