电子监控对不同的人意味着不同的东西。一些 你可能会听到并想象安装在关键地点的数码相机每天24小时被监控。另一个意思可能是门上的传感器导致事件被记录到数据库中。无论哪种情况，都有报警输入、报警传输和报警接收。这些是报警系统的原理。本文讨论了在选择监视系统时应考虑的问题，如:它的目的是什么；它将监测什么；它将如何监测；警报传输其信号的方法；还有，证明成本合理。许多不同类型的系统被描绘和描述。 包括数字。

Electronic surveillance means different things to different people. Some may hear it and imagine digital cameras mounted at key sites being monitored twenty-four hours a day. Another meaning could be a sensor on a door causing an event to be logged to a database. In either case there is an alarm input, the transmission of the alarm, and the reception of the alarm. These are the mechanics of the alarm system. This paper discusses what to consider in choosing a surveillance system such as: what it's purpose will be; what it will monitor; how it will monitor; the method by which the alarm transmits its signal; and, justifying the cost. Many different kinds of systems are pictured and described. Includes figures.