Abstract: A personal security communication system provides an indication that a worker may be incapacitated. The system may be configured as a buddy system comprising first and second portable units (100 and 200) acting as a pair (98). Each portable unit (100 and 200) produces status information and transmits data messages containing encoded status information to the other portable unit (200 and 100). The encoded status information includes a transmitting unit indentification number and alarm condition information produced by manual alarm switches (104 and 204) and sensors (102 and 202). The sensors (1102 and 202) may include a motion sensor (45) or a motion and position sensing switch (10) that produce motion and lack-of-motion signals that are encoded in the status information.

Abstract: A personal security communication system is disclosed. It is comprised of a motion and position sensor adapted to detect motion and lack of motion. The sensor has a motion and position sensing switch having means indicative of the motion of a contact making element in the switch and is adapted to provide at least a first and second electrical state according to the motion and lack of motion of the contact making element. Means is provided for detecting the first and second electrical state. The detecting means being adapted to provide a signal indicative of the electrical state of said switch. The system also includes user input means, processor means for receiving information from said motion sensing means and said user input means and adapted to format a digital data message indicative of said information, a transmitter means for transmitting said message, an alarm means activatable by said processor means and a power supply means for powering said processor means, transmitter and alarm means.