Design Of Monitoring System For Greenhouse Boiler Based On Wireless Sensor Network

In recent years,with the continuous progress of science and technology,greenhouse boiler monitoring system has begun to move towards the intelligent design.Especially the development of computer technology and Zigbee wireless sensor networks provided a new technical solution for the greenhouse boiler monitoring system.Based on the characteristics of Zigbee wireless sensor network,such as flexibility,low power consumption and feasibility,and combined with the existing boiler controller,the existing greenhouse boiler monitoring system has been redesigned.Compared with the traditional wired control mode,the new system can be more flexible,thus solves the problem of greenhouse wiring while saves the cost of monitoring.The design of the system is mainly focused on the following two parts: The first part is the Zigbee protocol conversion module which is consist of two protocol conversion modules: the RS485 interface and USB interface.The RS485 interface is used for connection with the boiler controller,which the USB interface is used for connecting with the host computer from the monitoring center.The existing greenhouse boiler controller has AI,DI,DO,RDT,RS485 and other interface circuits which can detect and control the environmental parameters of the greenhouse.Every Zigbee protocol conversion module was installed on the RS485 interface of each boiler controller,so that each boiler controller was equivalent to an acquisition sub-node.Data monitoring and transmission can be achieved through the Zigbee network which connects the sub-nodefrom the protocol conversion module in the boiler with the master-node from the protocol conversion module in the control center.The second part is the host computer monitoring software design.The boiler monitoring software designed based on VB6.0 can achieve work mode settings,boiler control,information collection,historical data query,report printing and other function son various nodes of the boiler.Data transmission was available through the Zigbee protocol conversion module of the host computer's USB interface.After completing the above plan to build a simple experimental platform,the function of the system was tested.Experiments show that the system can achieve the wireless networking function of the greenhouse boiler thus controls the boiler.Through the test,the structure of the system is shown to be reasonable and the performance stable.In addition,the number of nodes can be expanded when needed and the system's power consumption and maintenance cost is relatively low,compared with that of cable control systems.The new system has been proved to have an application value.