Explains the communication scheme of the master computer and the PLC as well as the communication scheme of PLC1 and PLC2 based on a mine hoist autocontrol system .
以上位机控制的矿井提升自动控制系统为例，介绍了该自动控制系统中上位机与PLC之间以及各PLC之间的通讯实现。
plc2