基于PLC与LabVIEW的恒温控制系统设计

Automatic Temperature Regulation System Based on LabVIEW and PLC

中文关键词:  温度传感器  PID  PLC

英文关键词:temperature sensor  PID  PLC

中文摘要:

      以NI公司开发的LabVIEW软件作为上位机软件和西门子S7-200型号的PLC为下位机，利用PT-100热电阻作为温度传感器，将温度信号转换为电流信号输入至具有4路模拟量输入，单路模拟量输出的西门子PLC功能模块EM-235中,并结合PID的控制理论设计了一套自动恒温控制系统。给出了系统硬件的框图，部分PLC程序以及LabVIEW的设计界面。对设计系统进行了实验，采用不同的PID参数进行控制，进行对比控制选择。根据实验数据可得温度控制的相对误差仅为0.1%，达到了预期的控制效果。

英文摘要:

      The automatic temperature regulation system is designed on LabVIEW by NI company as upper computer software and Siemens S7-200 PLC as slave computer，using PT-100 thermal resistance as temperature sensor,converting temperature signal to current input to the EM-235 of PLC special module,and combining with the PID control theory to this system.The block diagram of hardware structure,partial PLC program and the LabVIEW interface are given.Using different PID parameters for experiment with this system to compare the effect,experimental results show that the temperature control of the relative error is only 0.1%,which reaches the expected control effect.