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.