Comtrol Cable - Manual (Page 17)

Building Cables for RocketPort Products [Documentation number: 2000430 Rev B] 17
RJ45 Null-Modem Cables
RJ45 Null-Modem
Cables You need a null-modem cable to connect to DTE devices. For example, you can
connect one end of a null-modem cable to COM2 on one computer and the other
end of the null-modem cable to COM2 on another computer.
RS-232 Null-Modem
Cable The following RocketPort models support RJ45 null-modem cables on RS-232
ports:
• RocketPort PCI
• RocketPort Universal PCI
• RocketPort Plus Universal PCI
The following image displays the pinouts for an RS-232 null-modem cable.
Important: RJ45 pinouts are not standardized. Each peripheral manufacturer
uses different pinouts. Please refer to the document for the
peripheral device to determine the pinouts for the signals above.
Note: You can also attach a null-modem adapter to one end of a straight-through
cable to create a null-modem cable.
RJ45 Straight-
Through Cables Straight-through cables connect modems to other DCE devices. For example, you
can connect one end of a straight-through cable to COM2 on one computer and the
other end of the straight-through cable to a modem.
RS-232 Straight-
Through Cable The following RocketPort models support RJ45 straight-through cables on RS-232
ports:
• RocketPort PCI
• RocketPort Universal PCI
• RocketPort Plus Universal PCI
The following image displays the pinouts for an RS-232 straight-through cable.
Note: If your RJ45 wiring differs from the one shown above, adjust the RJ45
pinouts accordingly.
Ro
cketP
o
r
t
TxD
RxD
RTS
CTS
DSR
GND
DCD
DTR
Signal
RxD
TxD
CTS
RTS
DTR
GND
DCD
DSR
Signal
DB9
2
3
8
7
4
5
1
6
Pins
DB25
3
2
4
7
8
6
Pins
RJ45
4
5
1
8
7
3
6
2
Pins
20
5
Customer DTE
Roc
k
etP
o
r
t
DB9
1
2
3
4
5
8
6
7
Pins
DCD
RxD
TxD
DTR
GND
CTS
DSR
RTS
Signal
DCD
RxD
TxD
DTR
GND
CTS
DSR
RTS
Signal
RI 9
RJ45
6
5
4
2
3
8
7
1
Pins
N/A
DB25
8
3
2
20
7
5
6
4
Pins
Customer DCE
22 RI