毕业设计论文基于PLC的恒温控制系统摘要本文讨论了PLC(可编程逻辑控制器)在恒温控制系统中的应用。恒温控制系统中的恒温控制器是一种在一定点或一定温度范围内保持主体温度稳定的控制装置。它主要通过电路和感应元件对主系统温度进行感知和调节。该系统在温度控制中发挥着重要作用。当系统工作时，用铂电阻测量温度，然后将温度送到PLC。PLC开始比较可接受的温度和固定值。通过调整双向晶闸管在设定周期内的开关时间比，改变了加热线的电流和加热时间，最后控制了温度。以设计的水箱为例，阐述了PCL的工作原理。关键词：PLC温度PID控制CPU224EM235AbstractThis paper discusses the application of PLC (programmable logic controller)in constant temperature control system.The constant temperature controller in毕业设计论文the constant temperature control system is a control device to keep the main bodytemperature stable at a certain point or a certain temperature range.It mainlysenses and regulates the main body temperature through circuit and inductionelements.Temperature control is a very important part.The temperature ismeasured by platinum thermal resistance in the working process of the system,and the measured temperature is transmitted to the PLC.PLC compares the inductiontemperature value with the fixed value.After PID calculation,the ratio of on-offtime of bidirectional thyristor in the set cycle is adjusted,and the currentand heating time in the heating wire are changed to fulfill the temperature controlrequirements.Taking the designed water tank as an example,this paper expoundsthe working principle of PCL.Key words:PLC Temperature PID Control CPU224 EM235毕业设计论文目录1.前言1.1恒温系统应用1.2PLC的结构…1.2.1中央处理单元(CPU)1.2.2存储器1.2.3电源1.3.1LC的基本工作原理21.3.2PL0编程方式331.5PL0控制系统的构成设计原则及步骤4.41.5.2PLC的设计步骤2硬件设计…2.1工作过程.2.21/0地址分配72.3选择硬件…2.3.1CPU2242.3.2双向晶闸管…92.3.3热电阻原理构造.103.1PID的工作原理.3.2PID参数整定12133.3.1P1D回路表的格式及初始化133.3.2PID程序4.1顺序功能流程图4.2程序设计…20结束语…25参考文献…27