说明：  电视监控教材：典型的电视监控系统主要由前端设备和后端设备这两大部分组成，其中后端设备可进一步分为中心控制设备和分控制设备。
(TV monitoring Textbooks: A typical television monitoring system consists of two front-end equipment and back-end equipment parts, which can be further divided into back-end equipment and sub-central control equipment control equipment.)