Hi, I am using 8051 to control teh GSM module. Both are working fine with the terminal commands. But when I send the same command from the controlle rto modem, modem is not responding. i iwant the information from teh modem. so first I send the command and then I activated the serial interrupt to recive the data from the modem. Some where I am missing it out. Can somebody help me in thsi regard.thank you
"I send the same command from the controller to modem, modem is not responding."
There are many possibilities:
1. The controller never actually sent anything; 2. The controller sent something, but it was incorrect in some way; 3. The controller did send the correct command, but the modem never received it; 4. The controller sent the command, the modem received it, but didn't respond; 5. The controller sent the command, the modem received it, sent a valid response, but it never reached the controller; 6. The controller sent the command, the modem received it, sent a valid response, it reached the controller, but your software didn't correctly handle it.
You need to determine precisely what is & isn't happening.
Begin at number 1 above, and work your way through...
Note that, for most of it, it is irrelevant whether a modem or any other RS232 device is used - so test it with hypoterminal first...
Learn to debug - see: www.8052.com/.../read.phtml
There are very many things that can stop serial comms from working:
Software - including configurations of baud rate, parity, control signals, etc; Electronic hardware - including the RS232 transceiver; Other hardware - cables, etc.
You need to ensure that they are all correct & working!