I'm trying to connect a 3Com Router 3012 to the Internet using a GPRS connection through a Nokia 30. The 3Com router is connected to the Nokia 30 via an RS-232 connection.
We're able to successfully connect to the Internet using the Nokia 30 via GPRS. However, when we bring down the RS-232 link to the Nokia 30, the Nokia 30 keeps the DCD pin of the RS-232 link in the ON state. When this happens, we cannot reconnect to the Internet anymore as the router thinks that there is an incoming call and already tries to negotiate a PPP connection, which it should not be doing as the Nokia 30 hasn't connected to the other end yet.
We found out that the DCD was kept by the Nokia 30 by using an RS-232 breakout box. Shutting down the serial port of the router, which causes the DTR pin to go down, doesn't work. Sending an ATH command to the Nokia 30 from the router doesn't bring the DCD pin to the OFF state.
Is there an AT command that I could send to the Nokia 30 that would bring down the DCD pin to the OFF state? Below is some information on the Nokia 30 that we're using:
By the way, the Nokia 30 is set to &C1 - DCD in normal operation. Also, the router cannot be configured to ignore the DCD state.
I hope somebody out there could help me out with my problem.