1概述JBF-61S20防火门监控器(见图1)主要功能为:监控常开或常闭防火门的状态,实现实时显示及手动、自动关闭防火门等;监控器可与火灾报警控制器联网,并设置联动启动;回路线采用无极性、两线技术,最长通讯距离1 500 m。采用最新的61S总线通信协议,单回路容量可达252个地址点;主机容量,以双开常开防火 1 Overview JBF-61S20 fire door monitor (see Figure 1) The main function: to monitor the status of normally open or normally closed fire doors to achieve real-time display and manual, automatic closing of fire doors; monitor with fire alarm controller networking , And set the linkage start; return line with non-polar, two-wire technology, the longest communication distance of 1 500 m. Using the latest 61S bus communication protocol, a single circuit capacity of up to 252 address points; host capacity to open the normally open double fire