I have a problem. I have some program, which generate DTMF signal with the determinate parameters. I can`t set the determinate duration of the signal. There is keypad number set, but it should be hand-set. For example "3" "4" "2" . I mean, the signal of this numbers, which were fixed before, arise after the key START pushing. The signal (dual tone) should come out of each number with the definite (variable) duration, and definite (variable) interval between them.