An alarm system for recording the occurrence of an alarm condition in a predetermined space comprises a self-contained monitor which defines a sensor armed for sensing the alarm condition and a monitor transmitter which transmits a monitor signal in response thereto. In addition, the system comprises an interface module responsive to the monitor signal which communicates with a telephone line and a telephone answering machine associated with the predetermined space. The interface module includes an interface receiver circuit, a message generator which provides an alarm message, an off-hook telephone circuit, a telephone line simulator and a transfer switch. In response to the monitor signal, the interface receiver circuit operates the transfer switch to an activated position wherein the alarm message is transmitted from the message generator through the off-hook telephone circuit, the telephone line simulator and the transfer switch to the telephone answering machine for recording thereon. Subsequently, the user calls the telephone line to access the answering machine in order to retrieve the alarm message.
An apparatus and technique for providing a monitoring alarm telephone which not only automatically dials a predetermined alarm notification telephone number upon activation of a suitable alarm device (e.g., tripping of a motion detector), but which also provides audible monitoring of the secured premises using the automatically dialed telephone call. In one embodiment, an open channel is established between the monitoring alarm telephone and a called telephone allowing sounds from the secured premises to be passed on to the called party. A silent monitoring alarm is provided by muting the speaker of the monitoring alarm telephone upon activation of the alarm device. In another embodiment, a cordless telephone includes a motion detector and forms a monitoring alarm telephone. The microphone of either the remote handset or the base unit may be used to provide the monitored sounds to the automatically called party. Alternatively, sounds picked up by both the microphone in the remote handset and the microphone in the base unit may be combined (e.g., conferenced) and provided over the automatically established telephone call to provide flexible and thorough audible monitoring of the secured premises.
