apparatus utilizing conventional telephone lines to transmit a coded tone to a resetting apparatus installed in combination with a burglar alarm . the alarm system includes a plurality of series circuited switches utilized to maintain an alarm relay in an energized condition , when properly set to detect entry by unauthorized personnel at building openings , or other locations , each utilizing one of the series circuited switches . the instant invention responds to an incoming telephone ringing signal so as to simulate a timed pick - up of the switch hook of the telephone only when one or more of the series building opening entry detecting switches have been operated into an open position or upon an equipment failure which activates the alarm device de - energizing the alarm relay . upon receipt of a pre - determined coded tone , or series of tones , a tone detecting apparatus feeds a four in - put nand gate , preparing a circuit path for the reclosure of the alarm relay . a logic circuit is used to select the open alarm switch so as to simulate its closure . the alarm relay is restored to its energized condition preventing the apparatus from automatically responding to a second incoming call thereto unless another equipment breakdown or alarm switch circuit opening occurs .