3 ms·
Sorry, I should have specified more. This is a "potential entrant selects the person they're trying to visit; system phones the pre-programmed number for that
by cperciva 9y ago
Sorry, I should have specified more. This is a "potential entrant selects the person they're trying to visit; system phones the pre-programmed number for that occupant; occupant talks to the visitor and presses a button to let them in". In my building, I have to press 6 to make the door unlock.
Could a vistor play a very loud "touchtone phone 6" into the microphone and make the system think that the occupant pressed that number?
- mulmen 9y agoThat would require the audio signal to be a single channel right? That or the residents phone would have to be very loud. I'm not sure but I think phones operate on a dual channel (tx/rx) setup which is what allows all participants to talk simultaneously.
- cperciva 9y agoI was thinking echoing. I don't know how loud a button tone needs to be for the entryphone system to accept it as an instruction to unlock the door.