I have a Norstar MICS 7.0 that has a Interact 500 door opener. I made a change on a seemingly unused analog port (DN change) now the door opener does not work. When they press the button outside the secretary answers the call on a T7316, she would then press 6 to open the door. The door opener is on an analog port. It is not receiving the DTMF. Any ideas what I screwed up?