Design Of On-line Monitoring & Controlling System About Temperature & Humidity Based On B/s Model

Temperature and humidity on-line monitoring and controlling system is used widely, for example, grain depot, computer room, archives etc. In these places, the temperature and the relative humidity of the two physical must be controlled in a certain scope, can not be too high or too low. As the special requirements to the temperature and the humidity of these parts, the on-line monitoring and controlling system needs installed, and according to environmental requirements by the user to set the system temperature and humidity threshold, if the system monitors the temperature and humidity value over the threshold, the system starts automatically, if in the set value, the system stops working.The temperature and humidity on-line monitoring and controlling system could control automatically in accordance with the requirements to monitor the value, which is a closed-loop autocontrol system. The general system controlled by the MCU, reads the value from the temperature and humidity sensor, drives such as the nixietube to display the value, if it reaches the threshold, warning and starting the temperature and humidity adjusting equipment. The defects of this temperature and humidity monitoring and controlling system are:(1) Can not be stored and inquired the historical date;(2) If the distance between monitored objects and users is farther, for example WLAN, it is difficult to remote manage monitoring & controlling system.In order to solve these problems, the temperature and humidity on-line monitoring and controlling system based on the B/S mode is designed, which is divided into upper and lower parts. The lower part of the machine is the general temperature and humidity monitoring and controlling system, using fuzzy control, which composes of the AT89S52 MCU, temperature and humidity sensors, nixietube, serial port, EEPROM, replays and other hardware components, the upper component of the database and web site. The lower exchange the data with the database through the serial port send and receive data program, the users could operate the data in the database through the IE on the client, including examine real-time or historical temperature and humidity data and set alarm threshold. Client of the upper use B/S model, compared with the C/S model, there are three major advantages:(1) In the system maintenance, only need to protect the web servers, reduce the maintenance workload;(2) The user could access the system data only use the Microsoft's OS own IE browser;(3) Save the overall system cost, the client computer has low requirements to the hardware, just run the operating system and IE browser.After the system put into the computer room, has good use progress. Temperature can be controlled to 18℃-28℃, relative humidity can be controlled to 40%-70%, coincide with "Computer room design specifications".