《基于虚拟仪器的温度测控系统设计》.doc

编号： 摘 要： 1 0 前言 2 1虚拟仪器简介 3 1.1虚拟仪器 （VI) 的概念 3 1.2 LabVIEW 的概念 4 1.3虚拟仪器的优点 5 1.4 LabVIEW软件的简介 6 2 RS-232串行通信协议 8 2.1 LabVIEW串口VISA 8 2.2 RS232串口通信原理 10 3上位机测控系统设计 11 3.1串口的设置及预设温度输入 11 3.2温度的显示 12 3.3 温度的比较与警示 15 3.4LabVIEW前面板 15 4 下位机测控系统设计 16 4.1 下位机硬件设计 16 4.2 下位机软件设计 19 结论 23 参考文献 24 摘 要： 虚拟仪器（VI,Virtual Instrument）是基于计算机的仪器。计算机和仪器的密切结合是目前仪器发展的一个重要方向。虚拟仪器利用NI公司的LabVIEW软件及数据采集卡等硬件，取代以往由纯硬件构成的仪器测控系统。 温度检测与控制在工农业生产、医学研究等科研工作中具有非常重要的地位。本作品由一个PC，RS-232通信协议，一个AT89C51单片机及一个DS18B20及制冷与制热系统和相关外围电路组成。PC通过LabVIEW（Laboratory Virtual Instrument Engineering Workbench）向下位机发送预设温度范围，单片机通过串口不断向PC传送温度参数，实现温度的测量。单片机把DS18B20传来的温度与上位机发来的预设范围进行比较，根据比较结果控制外围电路的制热或制冷系统，从而实现温度的控制。该系统可用于相关温度控制领域。它具有数据处理能力强，通用性强，易于网络化以实现远程控制，耗材少，成本低等优点。 关键词： 虚拟仪器;串口通信;单片机;LabVIEW;温度控制 Based on virtual instrument of temperature measurement and control system Liu Ming (School of Physics and Electronics, Henan University, Henan Kaifeng 475004, China) Abstract: Virtual Instrument is a instrument which based on computer, The combination of computer and instruments is very popular nowadays . VI use LabVIEW,Data acquisition card and other hardware to replace the previous measurement and control system which just consist of pure hardware. Temperature measurement and control has a very important position in industrial and agricultural production, medical research. My works is made of a PC, an AT89C51 chip , a DS18B20 temperature sensor , cooling and heating systems and related peripheral circuit component.At first,PC send preset temperature range to MCU. then MCU transfer parameters through a serial port to PC,which complete the measurement task.Second, MCU decide whether present temperature is in the preset temperature range, and then control peripheral circuit to complete control function. The advantages of VI are data processing ability, versatility, easy to network to realize remote control, consumables less and low cost. Key words: VI ;Serial communication ;MCU ;LabVIEW;Temperature control 0 前言 当前的测温