Door ajar signalling device

Abstract

A door phone controller has a door ajar feature for alerting a user that a door was left open. The door phone controller accommodates the door ajar feature in several different ways depending upon how it is configured to interface with the central office line. If the door phone controller is configured to interface with the central office line as an individual station, then when a door is left open, the controller alerts the user via auxiliary alert contacts specifically provided for activating a customer chime. When the door phone controller is configured as a ring-down station, the door phone controller alerts the user that the door was left ajar by dialing a pre-programmed telephone number and sending a door ajar tone. If the door phone controller is configured as an interface with a trunk port, then when the door is left open, the controller alerts the user by ringing the trunk line and also energizing the auxiliary alert contacts. The user can both enable and disable the door ajar features via the telephone interface.