Improved protection for alarm communications systems

The alarm communications system can be thought of as consisting of five major components: alarm transmission, alarm displays and stations, alarm processing and software, line supervision, and other (e.g., enclosure protection). The authors illustrate a typical alarm communications system. The focus is on line supervision, particularly between the sensors and multiplexers. Modules from commercial vendors are being developed to provide enhanced line security (ELS) between the sensors and the data gathering panels or multiplexers (MUX). These modules are a promising new option for a physical protection system, and details concerning the evaluation and specific design requirements and functions are presented. The ELS systems currently being evaluated provide point-to-point protection between the sensor and MUX. The ELS systems were very reliable and required no maintenance once they were installed. The impact of encryption on the timely performance of the alarm communications system was evaluated.<>