Rs-422 Signal Wiring; Table 5.20: Terminal Without Handshake - Advantech PCI-1602UP User Manual

For DTE to DCE connections, use a straight through cable (i.e., you don't have to reverse
lines 2 and 3, lines 4 and 5, and lines 6 and 20 since, in general, the DCE RS-232 interfaces
are reversed themselves).

Table 5.20: Terminal without Handshake

Pin
2
3
4
5
7
6
20
8
Therefore, if you are not using CTS, RTS, DSR,DTR and DCD signals, short pins 4 and 5
together, and please short pins 6, 8,and 20 together.
5.2.2

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:
Table 5.21: RS-422 DB9 Pin Assignment
DTE (Male DB-9)
Pin
1
2
3
4
5
6
7
8
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+/-).
DB-25 Male
Signal
TxD
RxD
RTS
CTS
GND
DSR
DTR
DCD
Signal
TxD-
TxD+
RxD+
RxD-
GND
RTS-
RTS+
CTS+
Terminal, PC (DTE)
Pin
3
2
7
Terminal DTE
Pin
1
2
3
4
5
6
7
8
51 PCI/ PCI Express-Communication User Manual
Signal
RxD
TxD
GND
Signal
RxD-
RxD+
TxD+
TxD-
GND
CTS-
CTS+
CTS+