4 wire RS485 Full Duplex
RS422 is just RS485 network but with four wires. Dedicated 2 wires for Transmit and 2 wire for Receive. This makes RS422 full duplex meaning it can receive and transmit at same time unlike RS485 which is in half duplex mode which can either receive or transmit at any given time. RS422 is a full duplex configuration. RS422 using only 4 wire to communicate in both direction. With four wires, it means that when one side is transmitting, the other side of the communication line will be receiving. Both side can be transmitting at the same time.
Simple point to point setup for bidirectional communication in full duplex mode called RS422. Full Duplex here means from total four wires. Two wires are used for transmit while other two wires are for receive. Transmit has D+ and D- while Receive also has its own D+ and D-. They can transmit and receive at same time.
The transmit D+ and D- has to go to Receive D+ and D- of other side.