The Feed Batch System Controlled By PC And PLC

This is a technique innovation project of Beijing yong le dian feed mill.With the development of economy,batching system controlled by computer is put into use widely in feed industry.A new batching system is introduced which uses the new structure model of high level and low level computer,PC-high level computer,PLC-low level computer.It involves general system design,software and hardware design.Firstly general system design,the general design scheme is defined by comparing and analyzing total distributed control system and concentrated control system by computer in properties and using scopes.It is based on total distributed control thought and directed on concentrated control and dispersed management and is by structure model of high level and low level computer to accomplish system control goal.Secondly how to choose system hardware,hardware involves the choosing of high level and low level computer,communication hardware,sensor and weight indicator.The rule of choosing high level and low level computer is economic,meeting use requirement.Comparing industry control computer and personal computer,it is determined to use personal computer.Because industry control computer is more expensive in price than PC,considering the use,high level in this system emphasizes on management not control,PC is reasonable.The function of the low level computer is to execute the control,considering great disturbance on the spot and high-precision ruquirment,FX2N series PLC made in Japan is used by compare,whose high reliability meetsthe control requirements.The rule of choosing communication hardware is economic andpragmatic,without increasing investment of hardware,we use SC-09 programable cable to accomplish communication.Resistance strain sensor is choosed as weight sensor according to measure scopes and precision.XSB-I indicator is adaptable to weight indicator.Finally software design,batch management and report management software are developed by VB6.0,dababase management uses Access 2000.communication software is developed by VB6.0,which is based on deeply understanding the communication protocol,then communication funtion is all right finished.PLC control program is designed by ladder figure programmable software,control arithmetic and flow are given in this paper.After technique innovation,product efficiency and control precision are greatly improved and labor intensity of worker is obviously decreased.In addition,this project will be applied in else industry.