Design And Research Of Embededded PLC Extension Module With Interconnection Function

With the transformation and upgrading of industrial automation and the proposal of "made in China 2025",modern industry is gradually transforming from traditional manufacturing to intelligent manufacturing.The upgrading,intelligence and unmanned of the manufacturing industry bring new requirements and challenges to domestic automation enterprises.PLC,as an important equipment in the field of industrial automation control,will be more and more in demand in the future industrial manufacturing market.However,foreign PLC products have been monopolizing China's industrial market,which makes China's industrial control field at a disadvantage.In recent years,with the development of embedded system technology and high-performance ARM controller,embedded PLC emerges at the historic moment.Compared with traditional PLC,embedded PLC has the advantages of small size,low price and rich functions,and can be designed for the personalized needs of different customers.And the disadvantage of traditional PLC is poor compatibility and low cost problems,these problems embedded PLC can be relatively good to make up for and solve.The traditional PLC usually only has the input and the output outlet,along with the I/O port quantity increase,the price also increases along with,when needs other function expansion,needs to insert the corresponding function expansion module in the original PLC expansion interface,these expansion modules not only increased the volume but also the price is not cheap.For the shortage of the traditional PLC,this paper puts forward the extension module with the function of Internet embedded PLC,the extension module is based on the instructor's subject project,the main design content is done in senior function expansion on the base plate of the embedded PLC module,extension module circuit board can be connected with the basis of embedded PLC board,and extension module circuit board area and base plate about the same.The main task of this paper is based on the embedded PLC board function extension,on the base plate of the existing 64 output and input port 64 to extend,expand to 128 outlets and 128 input port,add A/D and D/A and RS485 communication function,the extension of the I/O port,A/D and D/A function designed connection function expansion board,the RS485 communication expansion on the base plate of pins extend,designs the overall scheme of the hardware circuit design and software design.The highlight of this module design is that the extension module can be designed into a structure that can be embedded and interconnected.It can be flexibly designed according to the needs of users,and the functions required can be customized to meet the diversified and differentiated requirements of users.This paper firstly introduces the background and research significance of embedded PLC,taking FX2 N type of mitsubishi PLC series as the research object,expounds the format and communication protocol of mitsubishi instruction,analyzes the wor king principle of interpreted and compiled PLC and explains the development mode of interpreted PLC.In learning,the internal structure of hardware and software of PLC and PLC on the principle of operation,we design a foundation plate extension module bas ed on embedded PLC's overall framework,extension module used for embedded PLC main chip and the extension of a chip module used in detail,respectively for extension board module of hardware circuit design,draw the circuit principle diagram and PCB and g ives the hardware circuit of the actual rendering;Second,using Keil software program of the hypogyny machine system development,the idea of modular design of embedded PLC extension module of software system,this paper expounds the system of variable,system initialization,data structure,design the function of directive function and various extension module procedures,respectively,the I/O expansion,A/D and D/A function and RS485 communication and other three modules.PC programming software USES mitsubishi PLC's GX Developer software to edit,compile,modify and store the ladder diagram.Based on the 32-bit ARM processor STM32F103ZET6 as the core of the system,this paper completed the hardware circuit and software design of the embedded PLC extension module,and debugged the software program and hardware circuit of the embedded system.Finally,the feasibility and rationality of the extension module of the embedded PLC system are verified.