The Research And Application Design Based On PLC Analog Control System

With the rapid development of automation industrial production, PLC (programmablelogic controller) as a specialized automation equipment used in industrial environments notonly holds dominat position in the industrial control area, but also has been graduallyimproving and perfecting in control size, control available and products.At present,PLC isused to control the analog available in a large number of industrial processes,PLC can processanalog available and PID data operation specially,and has other features,which makes itwidely used in the analog control systems of industrial production process.Join multipleadvanced technology, eventually implement PLC analog control system of integration,networking, and remote, it is important development direction of industrial production area.This article mainly aimed at PLC analog control system which was applied to the largehysteresis system, the research and design was about involved of problem, The specialprogramming method and control algorithm was effective to solve it, and summed up againstother special application of how programming method, and the research and design was aboutinvolved of problem related technology of how to realize the good of control effect and howto improve the performance price ratio of entire system.The project integrated with PLC, PCmachine, configuration software technology, MCU and CPLD technology, and introduces theadvanced of fuzzy PID control algorithm, composed a full of PLC analog control systemwhich had comprehensive and high performance price ratio. The design discussed how to usethe PLC as control core, and used supporting standard A/D and D/A special function moduleof PLC to compose PLC analog control unit, and used standard PLC PID function instructionsto control analog available; on this basis,analysis the problems of the above standard PLCcontrol system in the large hysteresis system,and bought the improved methods of PIDoperations module of PLC, and used PLC programming realize fuzzy PID algorithm, torealize the good control effect of the large hysteresis system; completed upper monitoringdesign through INSPEC configuration software, realizes in the superior machine to the PLCanalogue control system’s data acquisition, the curve demonstration as well as the control, andusing INSPEC configuration software’s network issue function, and realized the remotemonitor function by Ethernet communication; in order to make up for the disadvantages of thehigh cost,the less channel points and the fixed configuration in large data acquisitioncollected when used the standard PLC A/D and D/A, designed the PLC analog I/O modulebased on CPLD,and achieved PLC A/D, D/A module which had high performance price ratio,and according to the actual situation of project,complete custom function of I/O.Applied the project to the laboratory boiler control system project, achieved effective control of boiler liquid level and temperature, and had the upper monitor and remote function.The PLC imulation control system has some features about the strong comprehensive, highperformance price ratio,etc, through debugging the application projects synthetically,achieved the good control of hysteresis controlled object, and completed system designrequirements, and provides design ideas for the application of PLC in other specialcontrol,complex control of the field of industrial process control.