Db9 signals (rs- 422), Straight-through cables (dce), Null-modem cables (dte) – Comtrol RocketPort Plus 422 Universal PCI User Manual
Page 10: Db9 signals (rs-422)
10 - Connecting RS-422 Serial Devices
RocketPort uPCI Plus 422 User Guide: 2000370 Rev. B
Connecting RS-422 Serial Devices
DB9 Signals (RS-
422)
This subsection provides DB9 signal information. Refer to the
manufacturer’s installation documentation if you need help
with the connector pinouts or cabling for the serial device.
Note: DTE and DCE mode are controlled with the DIP switch on the RocketPort
uPCI Plus 422. See
Card and Interface Installation
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 DB9 Male Connector
Pins
DCE Mode
DTE Mode
1
Not used
Not used
2
RxD-
TxD-
3
TxD+
RxD+
4-6
Not used
Not used
7
RxD+
TxD+
8
TxD-
RxD-
9
Chassis Ground Chassis Ground
Pin 1
Pin 5
Pin 6
Pin 9
Male
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