Modem Tone Detection

[Ryo_Ohki2]

I've been trying to figure out how to use a modem to detect a key pad tone when pressed. I've seen a lot of posts about how to dial out, check if the line is ready, etc, but nothing really on detecting if a tone is pressed on the keypad. Examples would be greatly appreciated.

I guess the other thing would be is how would I detect the phone is ringing using a modem, and make it pick it up.

Note even though I'm not new to LabView, but I never used it before on controlling a modem so please keep it simple in explaining it to me.. Thanks.

[Rolf Kalbermatter]

I've been trying to figure out how to use a modem to detect a key pad tone when pressed.  I've seen a lot of posts about how to dial out, check if the line is ready, etc, but nothing really on detecting if a tone is pressed on the keypad.  Examples would be greatly appreciated.

I guess the other thing would be is how would I detect the phone is ringing using a modem, and make it pick it up.

Note even though I'm not new to LabView, but I never used it before on controlling a modem so please keep it simple in explaining it to me..  Thanks.

4881[/snapback]

Modems usually don't really have any tone detection built in. They don't need that as the tone detection is done by the exchange system from the network provider and that system routes the connection based on this information to the other side (in this case also a modem). Once the modem picks up the line the dialing from the remote side has already been finished.

NI had an example for a touch tone detector using their DAQ cards and a LabVIEW program.

As for detectiong the ring signal, that is an option you have to enable in the modem by sending it some command. Another command will enable auto pickup by the modem on the ring signal and you can usually set the numbert of ring tones the modem should wait before automatically picking up the line. What command to use you can find in the documentation for your modem. The modem actually will activate the RI line on the serial port and using VISA you can regularly poll that signal to see if the ring signal has been detected too.

When set to auto pickup, the modem will attempt to establish a connection with the remote side (if that is also a modem) and inform you of this by sending strings over the serial line.

Rolf Kalbermatter