Hang up voice call when ringing.

I'm trying to place a voice call using a GSM mobile phone (Philips
Fisio 825).
Therefore I'm sending ATDT <number>; and the call gets initiated as
expected.

The only problem is that now I would like to to terminate the call
after a fixed amount of time has elapsed (say 20 seconds) and I just
can't seem to get it right: ATH only work after the callee has
answered the call and even closing the serial com port doesn't help
(phone keeps on ringing).

I know that with data calls I can use ATS7=x to specify the # of
seconds after which the call should be terminated if no connection is
established, but what about voice calls?

Any help would be highly appreciated.

Wilson

You have to drop the DTR hardware signal.

"Wilson" <smokey_the_cat@libero.it> wrote in message
news:2f829caf.0501101359.5c44e579@posting.google.c om...
> The only problem is that now I would like to to terminate the call
> after a fixed amount of time has elapsed (say 20 seconds) and I just
> can't seem to get it right: ATH only work after the callee has
> answered the call and even closing the serial com port doesn't help
> (phone keeps on ringing).