Rs-422 Signal Wiring; Table 5.31:Rs-422 Db9 Pin Assignment - Advantech PCI-COMM Series User Manual

5.2.2 RS-422 Signal Wiring

The RS-422 interface wiring is based on one-to-one principles. The trans-
mit lines on one side connect to the receive lines on the other side, and
vice versa. With RS-422, you can transmit and receive data simulta-
neously (full duplex). The connections are as follows:
Table 5.31: RS-422 DB9 Pin Assignment
DTE(Male DB-9)
Pin
1
2
3
4
5
6
7
8
9
Terminator Resistors Setup
The signals DSR, DTR and DCD are shorted internally on the PCI-1601/
1602/1611/1612/1622 cards when operating in RS-422 mode.
A user can solder in termination resistors if necessary for impedance
matching. The card has two mounting spaces for termination resistors,
but no resistors are installed at the factory. Each pair of signal lines has a
separate resistor (RxD+/-, TxD+/-).
PCI-COMMUNICATION User Manual 94
Signal
TxD-
TxD+
RxD+
RxD-
GND
RTS-
RTS+
CTS+
CTS-
Terminal DTE
Pin Signal
1 RxD-
2 RxD+
3 TxD+
4 TxD-
5 GND
6 CTS-
7 CTS+
8 RTS+
9 RTS-