The Electronics Industry Association (EIA) has developed standards for data communication. EIA standards where originally marked with the prefix "RS". "RS" means that it is a recommended standard, but the standards are now generally indicated as "EIA" standards. RS422 was developed for greater distances and higher baud rates than RS232. It also enables a bus like structure with up to ten receivers, but it is not a true multi point network there every node could work as transmitter or receiver.

RS422 is a differential voltage loop interface (balanced differential signal); differential data transmission reduces the effects of ground shifts and induced noise signals.

logical "1" (Mark) is represented by a negative voltage of -3.6V to -6V,
logical "0" (Space) is represented by a positive voltage of +3.6V to +6V,
RS422 can be connected to up to ten receivers,
the data rate is up to 10 Mbps,
cable length could be up to 1.3 km (4000 feet),
the connector is a 37 pin D-Sub connector.

Cat5 cable (shielded twisted pair (STP) or unshielded twisted pair (UTP)) generally exceeds the recommendations for RS-422 and RS-485 systems.