72 Appendix A Technical specifications
NN46110-316 03.01
Figure 18 Modem cable (9-pin D-sub plug to RS-232-C modem plug)
The following table provides the multiple DB9 and DB25 serial interface cable
pinouts.
Modem cable specifications
If you need to connect a modem to a VPN Router 1750, you must obtain an
appropriate modem cable. The modem cable must have a 9-pin D-sub plug that
connects to the VPN Router 1750 serial port and a 25-pin D-sub plug that
connects to the RS-232-C modem port. “Modem cable (9-pin D-sub plug to
RS-232-C modem plug)” on page 73 shows the cable ends.
Table 19 Multiple DB9 and DB25 connector pinouts
Serial port
DB9 connector
Serial port
DB25 connector
Serial port
DB25 connector
Serial port
DB9 connector
Pinout Signal Pinout Signal Pinout Signal Pinout Signal
2RXD3TXD>2RXD3TXD
3TXD2RXD>3TXD2RXD
4DTR20DSR>6DTR6DSR
5 Ground 7 Ground > 7 Ground 5 Ground
6DSR6DTR>20DSR4DTR
7RTS4RTS>5CTS8CTS
8CTS5CTS>4RTS7RTS
Pin 1Pin 5
Pin 6Pin 9
10 ft
(3.05 m)
9-position D-sub receptacle with screw locks
(ground shield connected to backshell)
CAB0056A
Pin 13
Pin 1
Pin 25
Pin 14
25-position D-sub plug with screw locks
(ground shield connected to backshell)