Specifications

Chapter 5 Pin Assigment & Wiring 73
RS-422 signal wiring
The RS-422 interface wiring is based on one-to-one principles. The
transmit 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
simultaneously (full duplex). The connections are as follows:
DTE (Male DB-9) Terminal DTE
Pin Signal Signal
1 TxD- RxD-
2 TxD+ RxD+
3 RxD+ TxD+
4 RxD- TxD-
5 GND GND
6 RTS- CTS-
7 RTS+ CTS+
8 CTS+ RTS+
9 CTS- RTS-
Terminator Resistors setup
The signals DSR, DTR and DCD are shorted internally on the PCI-
1601/1602/1612 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+/-).