RS422 interface and RS485 interface

RS422 connection specific reference website

RS485 interface

• RS485 devices half-duplex device, RS485 transceiver associated signal pin comprises a control pin, 485A, 485B, wherein the high and low control pin determines the current in the receive mode or transmit mode.
• RS485 devices connected multipoint and point to point connection supports, the need to ensure 485A interconnected between devices on the terminal, 485B are connected to each other. Diagram below, to the left, point-to-multipoint connection right is:
  

RS422 interface

• RS422 device is a full-duplex device, equivalent to two-way RS485. RS422 transceiver has two control pins, each of 4 signal pins (TX +, TX-, RX +, RX-), wherein the pin TX + 485A equivalent to the RS485, RS485 pin 485B of the TX- equivalent. If the RS422 interface identified as A, B, Y, X four names, the RX + RS422 corresponding to Y, Z is the corresponding to the RX- RS422.
• Two control pins RS422 transceiver required to work with the working mode of operation of RS422.
• RS422 device also supports point-to-point and multipoint connections, wiring and RS485 interface to connect different. Diagram below, to the left, point-to-multipoint connection right is:
  

Both Contact

• RS422 RS485 transceiver may be used as a network, but can not turn RS485 transceiver for RS422 network.
• Need to control RS422 RS485 transceiver for using two control pins are at the same level, to ensure the transceiver operates in the half duplex mode. Short circuit diagram is as follows: