How to make a tone with 56k modem?

Question

I have a USB 56K Modem, and a locked door in a condominium.

When a user "dials" me, I must "anwser then press 6" on the phone. So I'm trying to send a tone to the cable....

I've added a new Windows 10 remote dial-up connection to the number 6. Named "door"

So in console I would get: rasphone -d door

But doesnt works..... How can I open this dooor with my computer? [Android :D]

Answer 1

The modem waits for the dial tone before sending the DTMF codes. You have to get your modem to send ATDT command without dial tone.