American District Telegraph Company

Mario D Casamassima

John K Guscott

Alarm system apparatus and method for optically transmitting information indicative of system operational status from an alarm detection unit to a remote receiver. The alarm detection unit includes a light emitting element for optical transmission of diagnostic and other data to the receiver. The light emitting element is pulse activated in accordance with a specified protocol to optically transmit data serially to the receiver, and the receiver is adapted for decoding of the serially transmitted data to provide an output indication to a system user indicative of detection unit operational parameters. One embodiment of the invention includes a bar graph indicator to provide a visual indication of selected operational parameters as an aid to a user in assessing system performance characteristics.

Security system status reporting

A temperature compensated alarm system includes a temperature transducer operative to produce an electrical output signal indicative of the ambient temperature, an alarm sensor, an electronic processing module, and a plurality of addressable registers for storing alarm threshold limits applicable at the operative ambient temperature. At selected times the electronic processing module reads a value indicative of the ambient temperature and thereupon determines the applicable alarm threshold limits by addressing the respective registers containing threshold limit data for the particular ambient temperature. In one embodiment, two sets of registers are provided; one set of registers containing higher sensitivity threshold limit data and the second set containing lower sensitivity threshold limit data. The applicable threshold data is determined by the state of a user settable switch.

Growing community of inventors

Randolph, MA, United States of America

Mario D Casamassima