What is DMX?

Date：2023-03-25

What is DMX?

DMX, also known as Digital Multiplex, is a protocol used to control devices such as lights or fog machines in performance settings.
It is the standard digital communication protocol that is used to remotely control intelligent lighting fixtures. 
DMX512 (Digital Multiplex with 512 pieces of information). Originally intended as a way to standardize communication among lighting dimmers  .

Where use?

Choice for stage lighting, upscale venues, and complex lighting effects. Afterwards  business owners realize can complete control the lighting from one location,then decorate bars and restaurants consider DMX as the most convenient and practical option for lighting. At nightclubs, festivals shows,theater shows etc.entertainment lighting ,also many  complex architectural lighting scenarios and interior lighting. 

Why is 512 Channel?

Sometimes DMX is referred to as DMX 512. This refers to the 512 channels a single DMX installation can control.Each channel is chosen to control different lights, such as color, rotation, and strobe. A channel is made of 255 steps assigned to control elements in each light. The DMX controller sends a value between 0 to 255. This value corresponds to the lighting intensity&brightness from 0 to 100%.This value is also known as the address, and every receiver (fixture) must be given an address.
  All the fixtures need to be write an address with address writer,so it knows what color it is supposed to be, for individual control of fixtures they need to have different addresses, there is no reason not to use the same address if you want the fixtures to do the same things. Each fixture takes up a space in the universe, if a fixture uses 4 channels and is addressed to one the next available address a fixture could use is 5.

What is Fixture Master/Slave, dmx universe. DMX controller.

Fixture master /Slave: Any object that takes DMX input. Receives a full DMX packet, picks out and listens data relevant to itself   Most Fixtures have an output channel that is simply a copy of the input.
Universe: A DMX universe is a set of channels,a Universe consists of a set of fixtures all strung together reading the same data. A Universe contains 512 bytes of information, so the amount of fixtures in a universe will depend on how many bytes of data are needed to address each fixture.
Controller: Creates and sends DMX data to one or more Universes. Usually, this a large board with many knobs and sliders, however, a simple PC can be used as a DMX controller.

DMX XLR-3, DMX XLR-5

Pin	XLR-3	XLR-5
1	GND	GND
2	Data 1 -	Data 1 -
3	Data 1 +	Data 1 +
4	N/A	Data 2 -
5	N/A	Data 2 +

Why need 120Ω resistor?

(The DMX standard recommends a maximum run of a thousand feet),called 300m.It is also wise to fit a 120Ω termination resistor between the two data lines at the extreme end of the chain of DMX devices to prevent signal reflection.An unterminated DMX line can cause flickering in your whole Universe, so be sure the line is terminated.

How to operate DMX?

DMX is a lighting control protocol which allows users to have ultimate control over their lighting needs.

There are all sorts of lighting fixtures that operate with DMX. After you have your entire fixtures daisy chained, or interlinked with each other, you must address them. Addressing fixtures will give them a start DMX channel which means that’s where the signal will be sent for that individual fixture. Each fixture will require an amount of channels to work, so depending on the amount of channels a fixture has, you will then address the rest of the fixtures on the next available channel after giving the previous fixture room to operate.

For example, an RGBW LED fixture will take up 4 DMX channels. If it addressed to channel 001, it will then take up channels 001, 002, and 003,004. The next free channel after that would be 005. You can also put 2 equal fixtures on the same address and they will both perform as one. You can use this technique to build your DMX line, or universe. An Example of a DMX RGBW Flood Light 150W work with 230V 50m RGBW PWM LED Strip via DMX control Customer want whole building change color together,sync the color means,he wants to use flood light and led strip,as linear light wall washer RGBW DMX is high cost,so we come up solution with using 230V LED strip RGBW 50m/roll,save his cost,and the effect is due,so we suggest an entire system for their mock demo to his customer.

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