https://www.electroschematics.com/an-introduction-to-the-digital-multiplex-protocol/
The Digital Multiplex (DMX) protocol is everywhere in lighting, so if you’re fiddling with lighting, it’s not going to be long before you start to have questions about the versatile lighting control protocol, which allows you to have the ultimate control over your lighting requirements. Presented below is a primer to explain the simplified function of a DMX signal control system.
What is DMX?
DMX was developed by the United States Institute for Theatre Technology (USITT) in 1986 mainly for controlling lighting equipment and accessories in entertainment applications. DMX set the bar for lighting manufacturers to build fixtures that would all be compatible with each other for controlling everything from a single source, thus giving improved freedom and flexibility, especially when it came to creating lighting shows. DMX is, in fact, a very popular protocol in which a DMX controller communicates to DMX luminaries. Nowadays, it is widely used in architectural scene-setting applications as well.
DMX requires different components to work. DMX control is usually achieved with a DMX controller/console, and the “addressable” lighting fixtures are usually interlinked with each other (daisy-chained) using DMX cables, usually three- or five-pin XLR. The DMX controller sends DMX values, which is an 8-bit value (between 0 and 255) corresponding to a 0% to 100% intensity. In DMX512, strings of 512 values are send 40 times per second, and the location of a DMX value is referred to as the “address.” By addressing the DMX device, it knows which DMX value to use.
Introduction
The Digital Multiplex (DMX) protocol (not the rapper : ), also known as DMX512 or DMX512-A, is an industry-standard method of achieving lighting control, both manually (using a control panel) and for lighting automation (using a PC). It finds uses in nightclubs, restaurants and theatres.
Lighting controllers generate serial signals in a format called DMX512 (I’ll use the term DMX for ease of reading throughout this blog post), and the lighting controller output is connected to a light fitting. Each DMX-capable light fitting has a DMX input, and a DMX output. It is a master-slave system where the lighting controller acts as the master, and the light fitting acts as a slave to the controller but as a master to the next light fitting that is attached.
