Temperature And Humidity Control System Based On Internet Design And Implementation

With the further spread of the Internet, the continuous improvement of the network bandwidth capacity and stability for the realization of an Internet-based measurement and control system to create more and better condition. Distributed and networked measurement and control system has become a trend. Follow this trend, we researthed and achieved an Internet-based measurement and control system High-speed Ethernet plays the role of the on-site measurement and control subsystem.In this subsystem,we use the gateway node to manage the data acquisition and control unit.s and through it to communicate with the Server on the Internet.The Internet Server,by providing the web service interface,can communicate with the third-party applications. The user can achieve measurement and control system management through web pages,by remote login. The communication mode of this system, begin with measurement and control subsystem level, is all the use of network communication. Communication of the on-site measurement and control subsystem,between the gateway node and data acquisition and control nodes,is network communication.The network communication function on data acquisition and control node is achieved by porting TCP/IP protocol stack to8bits Enhanced MCU C8051F340. On the communication protocol selection, in order to achieve the transparent transfer of data, the network communication between on-site measurement and control subsystems and the gateway node is using HTTP protocol,network communication between the gateway nodes and Internet server is also using the HTTP protocol. According to this design, a specific application of temperature and humidity measurement and control system is achieved based on the Internet. On the design and implementation of the control node, by analysis of single-chip network communication test board, this paper improved,simplified and redesigned the node used in the measurement and control system. On the design of the monitoring software, in order to reduce the network bandwidth of the control system and to improve the efficiency of measurement and control system, the software design of the gateway node has joined the the function of parameters configuration, the Internet server need to send configuration information to the corresponding gateway node, gateway node can maintain the normal operation of the on-site measurement and control subsvstem.