(Formerly "RS-422") An eia serial line standard which specifies 4-wire, full-duplex, differential line, multi-drop communications. The mechanical connections for this interface are specified by eia-449. The maximum cable length is 1200m. Maximum data rates are 10Mbps at 1.2m or 100Kbps at 1200m. EIA-422 cannot implement a truly multi-point communications network (such as with eia-485), although only one driver can be connected to up to ten receivers. The best use of EIA-422 is probably in eia-232 extension cords.

comparing eia-422, 423, 449 to rs-232-c. details on rs-232, 422, 423 and 485.