He wanted a security system with motion detection and CCTV cameras. The system had to be expandable and have telephone control. It also had to be designed so teachers who work evenings, holidays, and weekends, could get into their classrooms-including remote classroom portables-without having to turn off the entire system. Telephone control would give Sheldon the ability to check on the arming level of the system from his home. If someone should forget to arm the system, for example, he could arm it using his kitchen telephone.

The main controller for the Sierra Vista system is a monitored Security Pro® 4000. Subsystems in each classroom consist of motion sensors and a controller equipped with specially coded wireless transmitters that communicate with the monitored GE Security Pro 4000. When a motion sensor is activated by someone breaking into a classroom, a relay in the subsystem trips a wireless transmitter whose signal is received by the monitored main controller.

The individual classroom subsystems are not wired for individual monitoring because there are no telephone connections in the portables, but even if there were the school would not be able to pay for individual monitoring of each portable. Instead, wireless sensors on each subsystem controller pinpoint which classroom or portable is in alarm. In addition to eliminating the need for phone lines to be run to each portable, wireless transmitters prevent the need to run wires from the GE Security Pro 4000 to the remote classrooms.

According to Sheldon, the $35,000 camera and security system has done the job. Computers, printers, TVs, VCRs, and other valuable equipment have stopped disappearing from Sierra Vista Elementary School.