EIA485(RS485)
DMX512 is designed around the industry standard EIA485 interface. EIA485 belongs to the "electrical" end of the interface, voltage, and current.
The system is based on the downward symmetrical transmission of shielded conductor twisted pairs. This winding structure ensures that the interference generated will act equally on both signals, thus ensuring consistent digital phasing. The wires used should be suitable data wires made up of one or two twisted pairs, foils and woven screens. Symmetric audio conductors cannot do this.
Normally, as with any segment, there should be two terminals at each end of the wire. The lighting console is usually on one end as a terminal, and the other end should only have a 120惟 resistor.
The EIA485 specification only supports "daisy chains" or serial networks consisting of up to 32 "unit loads" per segment. Manufacturers claim that each segment can be up to 1000m. However, it should be particularly pointed out that the role of repeaters should take into account about 700m or 800m, which can prevent environmental anomalies.
