American District Telegraph Company

Kronos, Inc.

Sheldon P Apsell

Aaron A Galvin

Richard E Crandall

Larry K Baxter

Daniel Crown

Robert D Cohen

Mark S Ain

A multiple zone intrusion detection system in which a plurality of intrusion sensors can be readily converted into the system without system modification, and in which mode control signals from a central control unit and alarm signals from the sensors are both conveyed on a single conductor of the system cable. Each sensor has an associated interface module which permits coupling of different types of sensors to the system and sharing of a single conductor for mode control signals and alarm signals.

Multiple sensor intrusion detection system

This disclosure is concerned with time-clock recording and computation that, through a novel clock track card and separate clock track and data channel optical reading, in cooperation with microprocessor calculation, storage and control, enables automating employee time and attendance and similar data in a format directly recordable on the card and also directly useable by payroll or other processing computers and the like.

Methods of and apparatus for time clock recording and computation and

A multiple sensor intrusion alarm system including a central controller which communicates with a plurality of sensors over a single, interconnecting cable. The controller periodically polls each of the sensors, and in response to this polling signal, each sensor returns a signal indicating its status. The absence of a return signal from a particular sensor indicates to the controller that the sensor is malfunctioning or has been tampered with. In a preferred embodiment, the interconnecting cable is a single, two-conductor cable. The controller may also be connected to an alarm panel or remote monitoring station to indicate the presence of an alarm condition.

Multiple sensor intrusion alarm system

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Nahant, MA, United States of America

Sheldon P Apsell