1、 - I - 基于 plc 的温度和湿度 的 检测和显示 摘要 本论文主要讲述了基于西门子 S7-200 系列可编程控制器（ PLC）为主要的控制元件，实现对环境的温度和湿度进行实时检测和显示，并同时实现对时间进行显示和校正等功能的显示装置的设计方法。 本设计的传感器部分采用集成温度和湿度传感器，集成传感器具有功能强、精度高、响应速度快、体积小、微功耗、价格低、适合远距离传输信号等特点。集成传感器的外围电路简单，具有较高的性价比。经过选择集成温度传感器采用电压输出式单片精密集成温度传感器 LM35 系列产品；集成湿度传感器选择线性电压输出 式集成湿度传感器 HM1500，它的主要特点是采用恒压
2、供电、内置放大电路、能输出与相对湿度呈比例关系的伏特级电压信号、响应速度快、重复性好、抗污染能力强。显示部分采用 LED 七段码进行显示， 本装置一共使用了十七个LED 数码管进行显示，能够同时显示当时环境的温度、湿度和时间，还可以显示年月日等信息，并能实现当环境的温湿度超过一定范围时进行报警的功能。 关键词： PLC； 温度传感器 ； 湿度传感器 ； LED 显示装 置 - II - The design of detection and display about the temperature and humidity based on PLC Abstract This paper m
3、ainly based on Siemens S7-200 series programmable controller (PLC) for the control of the main components realize the environmental temperature and humidity for real-time detection and display, and to simultaneously achieve right time and calendar set up for display and function display devices desi
4、gn methods. The design of the sensor using integrated temperature and humidity sensors, sensor integration with functional and high accuracy. Fast response, small size, very low-power, low price, suitable for long-distance signal transmission characteristics. Integrated sensor external circuit is si
5、mple and low cost and high performance. Selected integrated temperature sensor output voltage precision-integrated single-chip temperature sensor LM35 series of products； Integrated humidity sensor option linear voltage-output integrated humidity sensors HM1500. Its main feature is the constant volt
6、age power supply, a built-in amplifier, can be output with the relative humidity is the ratio between the voltage level signal voltage, fast response and good reproducibility, anti-pollution capability. LED used in some of the display code in paragraph 107, the device used a total of 17 LED digital
7、tubes, can also showed that environmental temperature, humidity and time, can also display information such as the date, and the environment can be achieved when the temperature and humidity of more than a certain scope for alarm functions. Key words: PLC； Temperature sensor； Humidity sensor； LED display devices
