To enhance the quality of manufacturing as responsibility, build national brand of measurement!
To enhance the quality of manufacturing as responsibility, build national brand of measurement!
RS485采用半双工通讯，并且是单主机模式，主机一般通过ID轮询的方式与各个子站建立通讯，各个子站的采样及测量通常不同步。
若需要同步测量，可通过广播指令进行同步：设置一个专用ID，作为广播地址，所有子站均可接受以该ID起始的指令。所有子站同时接受到广播指令，同时开始测量，随后，主站依次轮训各个子站，各子站将同步测量结果依次上传。即：同步启动，顺序读取。
采用上述方案，只要各个子站对同步指令的处理速度足够快，可以实现较高精度的同步测量。
DMC300分布式测控系统就是采用上述方案实现多个子站之间的同步测量。
China's leading enterprise in variable frequency power measurement and metering
National variable frequency power measuring instrument (metering station) founder
Research and development unit of national variable frequency power metering standard