基于嵌入式软PLC分布式控制系统设计

Design of distributed control system based on embedded soft PLC

摘要:

为了确保PC端主机所生成指令程序满足PLC控制原则，使PLC编程器的逻辑编译能力得到保障，提高指令编码准确性，设计基于嵌入式软PLC分布式控制系统。根据软PLC定义标准，确定系统结构的组成形式，再通过分析工作执行机制的方式，完成对嵌入式软PLC系统的技术基础研究。在分布式体系中，同时开发I/O驱动程序与PLC执行程序，并联合下级PLC编程器设备，确定CODESYS工程组件的实时运行状态，完成分布式控制系统的I/O组件设计。按照实时内核的进入与退出模式，定义分时映像区取值范围，借助数据库主机中存储的控制指令执行程序，求解指令逻辑栈表达式，实现对软PLC驱动模式的规范，完成基于嵌入式软PLC分布式控制系统设计。实验结果表明，本次实验所选10条指令程序的PC端输出结果均满足PLC控制原则，在保障PLC编程器逻辑编译能力方面具有突出作用价值，且能够有效提高指令编码准确性。

Abstract:

In order to ensure that the instruction program generated by the host computer at the PC side meets the PLC control principle, ensure the logic compilation ability of the PLC programmer, and improve the accuracy of instruction coding, a distributed control system based on embedded soft PLC is designed. According to the definition standard of soft PLC, determine the composition form of the system structure, and then complete the technical basic research of the embedded soft PLC system by analyzing the work execution mechanism. In the distributed system, the I/O driver and the PLC execution program are developed at the same time, and the real-time operation state of the CODESYS engineering components is determined in conjunction with the lower level PLC programmer equipment to complete the I/O component design of the distributed control system. According to the entry and exit modes of the real-time kernel, the value range of the time-sharing image area is defined. With the help of the control instruction execution program stored in the database host, the instruction logic stack expression is solved, the specification of the soft PLC drive mode is realized, and the design of the distributed control system based on the embedded soft PLC is completed. The experimental results show that the PC output results of the 10 instruction programs selected in this experiment all meet the PLC control principles, have outstanding value in ensuring the logic compilation ability of the PLC programmer, and can effectively improve the accuracy of instruction coding.