Automatic systems used by asterisk and Sipura 3000

Hi! sorry, if something like this allredy has been! I’m new here
I have got problems with Sipura 3000 and the way how she sends DTMF signal.
-> I am using SIpura 3000 to open doors. the door lock (Farfisa) is connected with line port, but phone is connected with phone port. when the farsifa is makeing call, I pick up the phone and press 2 times flash button( to open door I have to do this). when I press flash button, nothing is happening