EIA-485
<communications, standard> (Formerly "RS-485") An
EIA serial line standard which specifies 2-wire,
half-duplex,
differential line, multi-point communications.
Maximum cable length is 1200m.
Maximum data rates are 10Mbps at 1.2m or 100Kbps at 1200m.
EIA-485 can implement a truly multi-point communications network, and specifies up to 32 drivers and 32 receivers on a single (2-wire) bus.
Differential SCSI uses EIA-485.
Details on RS-232, 422, 423, and 485 (http://www.rs485.com/rs485spec.html).
