Research And Design Of High-performance PLC Based On ARM + FPGA Architecture

Programmable logic controller(PLC),as a kind of industrial controller,has many characteristics.S uch as simple structure,easy programming,excellent performance,convenience in applying and so on.Therefore,in recent years the development and application of PLC become more and more widely.Extension bus is a high-speed data path between PLC host and PLC extension modules.It's the core technology of design and manufacture PLC products.And its technical level determines the extensibility of PLC.However,with the increasing complexity of PLC applications,the requirements of real-time performance of PLC become more and more prominent.As some industrial applications require hundreds or even nearly thousands of I/O points,too many points make the real-time performance of PLC decrease,which may lead to a lot of stability problems.According to the functional requirements of PLC,this paper designs a high-performance PLC based on ARM + FPGA architecture.A high real-time extension bus with hardware address auto-location strategy is designed for this PLC.Meanwhile,this paper develops a matching ladder diagram programming system for this PLC.The mainly work of this paper includes the following aspects:1)Studies a variety of PLC hardware architectures,and analyzes the advantages and disadvantages of these different architectures.Thus,design a high-speed and easy-to-expand PLC based on ARM + FPGA architecture.2)This paper analyzes the logical structure of the stored data in the PLC ladder diagram.Using a transformation algorithm from ladder diagram to instruction list based on multi-tree,which improves the efficiency and versatility of traditionnal transformation algorithm.The PLC ladder diagram programming system is designed and developed by C#.Therefore,this paper implements the basic editing,compilation,and communication functions by this pragramming system.3)Comprehensive analysis the characteristics of various kinds of PLC extension buses,and proposes a high real-time extension bus with the characteristic of hardware address auto-location.Decides the overall plan of PLC hardware platfo rm,and designs the host module,typical IO module,analog module and communication module.The experimental results show that the plan is feasible,and the PLC system is flexible,real-time,reliable and convenient to extend.