hi !

thank you for the informative responses to my query.

actually, the problem of not getting an 'OK' response has been solved. The fault was in the circuitary i was using. It was due to the optocoupler that was being used to provide an isolation. Once it was removed i could dial the required no.

However the 2nd problem still remains.........

89C52 is able to communicate with modem at the baud rate of 57.6k baud. But for any baud rate higher than this the program fails. i.e i am not able to dial the no.

However, whenever i connect 89C52 to COM port at 115.2k baud , the commands which i am sending get displayed on the hyperterminal.


I am using the crystal of 22.1184MHz frequency with SMOD bit set.

should i write an interrupt driven program or polling would do ?

please help !

regards,

kunal.