Comtrol RocketPort Plus 422 Universal PCI - Manual (Page 11)

RocketPort uPCI Plus 422 User Guide: 2000370 Rev. B Connecting RS-422 Serial Devices - 11
Connecting RS-422 Serial Devices
DB9 Loopback Plugs RocketPort uPCI Plus 422 are shipped with a a single loopback plug. You can use
loopback plugs with application software (for example, Test Terminal) to test
serial ports.
Wire the following pins together to build additional plugs or replace a missing
loopback plug.
• Pins 2 to 8
• Pins 3 to 7
Note: DTE and DCE mode are controlled with the DIP
switch on the RocketPort uPCI Plus 422. See Card
and Interface Installation on Page 7 for information.
The factory default is set to DTE.
Straight-Through
Cables (DCE) Use the following figure if you need to build an RS-422 straight-through cable for
DCE devices.
Null-Modem Cables
(DTE) Use the following figure if you need to build an RS-422 null-modem cable for DTE
devices.
Note: RS-422 signals are not standardized and each serial manufacturer uses
different pinouts. Refer to the serial device documentation to determine the
pinouts for the signals above.
RS-422 (Back View)
Pin 5 Pin 1
Pin 9 Pin 6
Loopback
TxD+
TxD-
RxD+
Signal
3
8
7
Pins
RxD-
RocketPort Sony DB9 Connector DCE Mode
2
3
8
7
Pins
2
TxD+
TxD-
RxD+
Signal
RxD-
TxD+
TxD-
RxD+
Signal
7
2
3
Pins
RxD+
RxD-
Signal
TxD+
TxD- RxD- 8
DTE Serial Device RocketPort DTE Mode