小型PLC编辑与监控系统的设计

Design of Small PLC Editing and Monitoring System

为了克服现有小型PLC编程装置的不足,针对新型便携式PLC编程装置,构建了以ARM微处理器和μC/OSII系统为核心的小型PLC编辑与监控系统。系统设计了多操作位逻辑运算指令及其编码,制定了CAN扩展协议,采用双向链表动态编辑PLC源指令文件,进行分析、优化与错误处理,再编译成二进制目标代码文件,按照CAN扩展协议格式编码,通过CAN总线发送到PLC主机,可以监控主机的运行状态和软元件的信息。实验表明:该系统提高了编辑指令的效率和PLC主机的运行速度,实现了存储多套源指令文件并准确编译、高可靠性通讯、监控PLC主机的目的。

To overcome the shortcomings of existing small PLC programmable devices, according to the new type of portable PLC programmable device a small PLC editing and monitoring system with ARM microprocessor and IxC/OS - II system as the core was constructed. Logic operation instructions with multiple operands and their encodes were designed and realized. A CAN exten- sion protocol was formulated. Two-way chain tables were adopted to edit PLC source instruction file dynamically. The file was ana- lyzed, optimized and error handled, and was compiled to binary object code file. According to CAN extension protocol format, the object code file was encoded and was sent to PLC host via CAN Bus. The state of PLC host and soft component information were monitored. The results show that the system improves the efficiency of editing PLC instruction and the running speed of PLC host. Multiple sets of PLC source instructions files storage and accurate compiling, the highly reliable communication and monitoring PLC host are implemented.