CHAPTER 7
RS422/RS485 CABKUBG UBFIRNATUIB

7.1 RS422 Cabling Information for DB25

The communication interface follows the EIA RS422 standard.  The signal assignments for a standard DB25 connector are shown below:

Pin
 Description
1
Chassis Ground
2
Transmit Data+(TxD+)
3
Receive Data+(RxD+)
4
Request to Send+(RTS+)
5
Clear to Send+(CTS+)
6
 Receive Data-(RxD-)
7
 Signal Ground(SG)
8
  Request to Send-(RTS-)
22
Clear to Send-(CTS-)
20
Transmit Data-(TxD-)

To connect the RS422 to other DATA TERMINAL EQUIPMENT (DTE) devices, the developers recommend using a DTE to DTE connection as shown below.

HOST
 REMOTE
     Ground
     Ground
     Signal Ground
     Signal Ground
     Transmit Data(+)
     Receive Data(+)
     Receive Data(+)
     Transmit Data(+)
     Transmit Data(-)
     Receive Data(-)
     Request to Send(+)
     Transmit Data(-)
     Request to Send(-)
     Clear to Send(+)
    Clear to Send(+)
     Request to Send(+)
    Request to Send(-)
     Clear to Send(-)
    Clear to Send(-)
     Request to Send(-)


7.2 RS422 Cabling Information for DB9

The communication interface follows the EIA RS422 standard. The signal assignments for a standard DB9 connector are shown below:

7.3 RS485 Cabling Information for DB25

The RS485 signal assignment is shown as follows:

The RS485 communication is based on cable sharing method, which is connected as following:

7.4 RS485 Cabling Information for DB9

The RS485 signal assignment is shown as follows.

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