ARM+FPGA组成的PLC结构的通信系统

通过自主研制的ARM+FPGA组成的PLC结构通信系统设计的介绍,采用CAN总线实现系统中各模块间的通信功能.在详细分析PLC主机在上电、编辑状态和程序执行时的通信需求与特点的基础上,规范了通信内容达到通信系统的通用性,设计内容主要包括通信协议与通信标识符格式的设计,PLC主机通信软件模块的组成与操作流程,CAN通信发送和接收信息处理任务程序流程的设计等.经试验验证表明:该系统最终可满足PLC主机与各功能模块间不同的通信要求,实现PLC系统实时可靠的通信.

Communication system of the PLC composed by ARM and FPGA

This paper represents a design of PLC based communication system,which is composed of ARM and FPGA.The CAN bus is used to implement the communication between modules of the system.By analyzing the requirements and characters of communication of the PLC host in the stage of power-on,editing mode and executing mode,a universal communication pattern is realized.The pattern mainly includes three parts of criteria： the first part is the design of communication protocol and communication identifier format,the second part is that of the composition and operating procedures of the communication software for PLC host,and the last part is that of task processing procedures for the message sending and receiving of CAN bus.The results of validation experiments show that this communication system fulfills the requirements of reliable communication between PLC host and each module.