I-O Display Systems Basic I/O Product manual Installation, RS-422, RS-485, 2-4Vol.2

	Installation 2
RS-422:
Advantages:	Easier to implement in software since host driver need not be controlled.
	Can be either Multidrop or Repeat.
	No turn-around delay required.
Disadvantages:	Requires five conductor wire instead of three.
RS-485:
Advantages:	Needs only 3 wire conductor.
Disadvantages:	Host 485 driver control must be implemented requiring tricky serial port
	manipulations.
	Can only be Multidrop.
	Usually requires turn around delay implementation.

2-4(Vol.2)