Connecting Devices to the iNS
10
Figure 2-2, Figure 2-3, and Figure 2-4 show cable diagrams for three common configurations.
The cable shown in Figure 2-3 may be used to connect modems to the iNS/3000. Modems
should be configured to switch their carrier detect signal (CD) on and off in response to
making and breaking telephone connections. This insures that the iNS/3000 terminates user
sessions when they disconnect. The cable shown in Figure 2-2 can be used to connect a DB-9
terminal (or standard PC COM) port directly to the iNS/3000. The DB-9 to DB-9 terminal
cable diagrammed in Figure 2-4 is a standard NULL modem connector, readily available in
retail outlets. DB-9 to DB-9 modem cables (not diagrammed) require no special pinouts and
use a straight-through cable. A 3-wire cable is shown in Figure 2-5.
DB-9 Pin
Number
DB-25 Pin
Number/Signal
1 DCD
9 RI
8 CTS
7 RTS
6 DSR
5 GND
4 DTR
3 TX
2 RX
8 DCD
22 RI
4 RTS
5 CTS
20 DTR
7 GND
6 DSR
3 RX
2 TX
Figure 2-2: DB-9 to DB-25 Terminal Cable