基于串行通讯的PLC远程控制

PLC Remote Control Based on Serial Communication

为了实现在远方主站端对分布在不同变电站的低压开关柜进行远程控制,利用电力通信通道,扩展用于电力系统远程通信的CDT规约,使远程控制问题变成计算机串行通信问题.用串行通信技术方法,将远方主计算机的控制命令发送给变电站当地子站,子站计算机分析出主站命令,并转换成松下PLC通讯指令格式,用串行通信的指令系列代替PLC梯形图的编程,由子站直接控制PLC,实现对低压开关柜组的远程智能控制.通过现场调试和运行结果表明,利用电力系统数据传输通道,既不会影响高压系统的数据传输,又可以实现利用上位机的串行通信对PLC进行远程控制,解决了开关柜控制回路的远程智能控制问题,并给出了用串行通讯代替梯形图的编程方法及应用实例.

In order to control of intelligent low-voltage switch cabinet by use of PLC in different remote transformer substations. The following methods are adopted： communication channeling are shared, the construction of remote control are designed, serial communication to implement the remote control are used instead of PLC ladder logic graphic.and the CDT protocol which is widely used in the electric power area as a telecommunications protocol is extended. Furthermore. the MEWTOCOL-COM communication protocol to the Matsushita PLC is analyzed. On-the-spot test running shows that making use of these methods are quite suitable to remote control Programming Logic Controller. The corresponding examples are given in this paper.