DMX 512 protocol
DMX 512 protocol
The DMX 512 protocol is the abbreviation of digital multiplex.
The DMX512 protocol was first developed by usitt (American Society of Theater Technology) as a way to control dimmers from a console with a standard digital interface.
Simple, reliable, and flexible, it is a new field in science with all kinds of fantastic techniques based on rules.
Chinese name DMX 512 protocol Foreign name digital multiplex
DMX 512 is an international high-speed data output protocol, which adopts rs485 hardware circuit, which is different from general rs485 communication.
DMX is based on RS422/RS485 serial transmission, the data transmission rate is 250Kbps, the maximum loop control is 512 channels, and the allowable effective transmission distance is 250m.
1. Using one-way communication
2. DMX 512 communication needs to transmit a low-level data of 88us as the start frame header of a packet of data.
The receiver has a gap detection circuit, and needs to find the start frame header of the data, and there is no communication check.
3. The fixed baud rate of DMX 512 communication is 250kbps.
Due to the open communication protocol, high efficiency and reliability, it is widely used in the traditional stage industry.
Compatible with DMX 512 communication interface is the default choice in high-power LED lighting control systems.
DMX512 adopts eia-485 standard.
Transmitter: Logic "1" is represented by the voltage difference between the two lines + (2~6)v; Logic "0" is represented by the voltage difference between the two lines -(2~6)v; Receiver: a is 200mv higher than b The above is considered to be a logical "1"; if a is more than 200mv lower than b, it is considered to be a logical "0".
The transmission rate of DMX 512 is fixed at 250kbps, the time of each data bit is 4us, and each byte is eleven bits, which is 44us 1 second=1000 milliseconds 1 millisecond=1000 microseconds
Therefore, the data transmission time of 512 bytes is 44*512=22.528ms The data frame header is usually 88us, the data frame header is followed by an idle frame, the idle frame time length is 8us-1ms, before the 512-byte data packet There is also a byte representing the codename or custom of the device
DMX 512 XLR Cable
DMX 512 rs485 communication cable
DMX 512 communication interface cable