说明：  电视监控系统教材,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 system of teaching materials, the typical television monitoring system is mainly by the front-end equipment and back-end equipment, the two major components, the back-end equipment which can be further divided into sub-central control equipment and control equipment.)