Db9 Signals; Db9 Null-Modem Cables (Rs-232); Db9 Null-Modem Cables (Rs-422 Or Rs-485 Full-Duplex) - Comtrol RocketPort INFINITY User Manual

Connecting Serial Devices

DB9 Signals

DB9 Null-Modem
Cables (RS-232)
DB9 Null-Modem
Cables (RS-422 or
RS-485 Full-Duplex)
12 - Connecting Serial Devices
Refer to the manufacturer's installation documentation if you need help with the
connector pinouts or cabling for the serial device.
Pin RS-232
1 DCD
2 RxD
3 TxD
4 DTR
5 SIG GND
6 DSR
7 RTS
8 CTS
9 RI
Ground must be tied to signal ground.
Use the following figure if you need to build an RS-232 null-modem cable. A null-
modem cable is required for connecting DTE devices.
If you need RTS-CTS/DTR-DSR
hardware flow control, you can use
the pinouts provided in the
following example.
You may want to purchase or build
a straight-through cable and
purchase a null-modem adapter.
For example, a null-modem cable
can be used to connect COM2 of
one PC to COM2 of another PC.
Note: RJ45 connectors are not
standardized. Refer to your
serial device documentation
for signal information.
Use the following figure if you need to build
an RS-422 or RS-485 full-duplex null-modem
cable. A null-modem cable is required for
connecting DTE devices.
Note: RS-422 and RS-45 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.
DB9 Male Connector Signals
Pin 1
Pin 5
Pin 6 Pin 9
RS-422
(Full-Duplex)
Not used
RxD-
TxD-
Not used
SIG GND SIG GND
Not used
TxD+
RxD+
Not used Not Used
RocketPort
DB9
Signal Pins
TxD 3
RxD 2
RTS 7
RI 9
CTS 8
DSR 6
DCD 1
DTR 4
GND 5
RocketPort
Signal
RocketPort INFINITY User Guide: 2000465 Rev. G
RS-485 RS-485
(Half-Duplex)
Not used Not used
RxD- Not used
TxD- TRxD-
Not used Not used
SIG GND
Not used Not used
TxD+ TRxD+
RxD+ Not used
Not Used
DTE Serial Device
DB9 DB25
Pins Pins
2 3
3 2
8 5
9 22
7 4
4 20
1 8
6 6
5 7
DB9
Pins
TxD+ 7
TxD- 3
RxD+ 8
RxD- 2
Signal
RxD
TxD
CTS
RI
RTS
DTR
DCD
DSR
GND
DTE Serial
Device
Signal
RxD+
RxD-
TxD+
TxD-