Systech Corporation RCS/3000, Hardware Manual

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Installing the Hardware 9
6 DSR I Signals module that remote device is attached and
powered on
7 RTS O Flow control, to enable remote device to send data
8 CTS I Flow control, to enable RCS/3000 to send data on TX
9 RI I Ring Indicator
Table 3-1 EIA-232 DB-9 Pinouts
Table 3-2, Table 3-3, and Table 3-4 show cable diagrams for three common configurations.
The cable shown in Table 3-3may be used to connect modems to the RCS/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 RCS/3000 terminates user
sessions when they disconnect. The cable shown in Table 3-4can be used to connect a DB-9
terminal (or standard PC COM) port directly to the RCS/3000. The DB-9 to DB-9 terminal
cable diagrammed 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 Table 3-5 .
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
Table 3-2: DB-9 to DB-25 Terminal Cable