Rtu-To-Modem Connections; Rtu-To-Modem Asynchronous Connection - Motorola IRRInet-M DC Owner's Manual

RTU-to-Modem Connections

Only R&TTE approved modems should be used to connect the RTU to the
PSTN.

RTU-to-Modem Asynchronous Connection

For a 9-pin connection, use the FLN6458B cable kit to connect one of the IRRInet-M RTU
RS232 ports asynchronously to a modem. (The RTU serves as DTE.) The kit includes a cable
with RJ45 modular jacks on both ends and an RJ45 to 9-pin male D-Type adapter (see Figure
20 for RS232 and Figure 21 for RS232E). The possible RTU configurations are detailed below:
Port No. STS Definition
1 RS232 External Dialup Modem
1 RS232 External Modem
1. Before transmitting, the RTU sends an RTS=on signal to the modem,
2. The RTU will not receive unless it receives a DCD=on signal from the
3. When using a modem in auto-answer mode (connected to a computer
When the connector is facing upwards, the left-hand pin is Pin No. 1, and
the right-hand pin is Pin No. 8.
30
and will not transmit unless it receives a feedback CTS=on signal from
the modem.
modem.
port) for remote service, the RTU does not support the RTS/CTS
protocol, as the port is designed to operate with a local computer as
well as with a modem.
Appendix A: Cables and Adapters