Simple RS 422 transceiver
The interface RS 422 is a serial communication with differential signals for TX and RX. We have a TX that becomes TX+ and TX-, and a RX that becomes RX+ and RX-. There are two important advantages of a differential serial communication: the first is the high noise immunity, and the other is is the possibility of utilize long wires (up to 1500 m).
RS422 Schematic 
RS422 Transceiver Layout