Research On Distributed Supervisory System Based On Wireless Communication Intelligent Nodes

Along with the rapid development of the national economy, the modern agriculture has got substantial progresses and greenhouse engineering has become an important part of efficient agriculture. To meet needs for production and development of modern greenhouse, the system of wireless distributed monitoring is present to overcome the limit of the traditional wired system in greenhouse. Through comparing wireless technologies, computer exterior interfaces, channel access technologies and monitoring software, a plan based on terminal nodes, master controller and computer is proposed. The terminal nodes collect local information, transmit to the master controller node and send them to computer through USB interfaces finally. Adopting ForceControl configuration software to achieve real-time monitoring, thus wireless distributed monitoring of the greenhouse can be realized.In the thesis, we introduce the operation principle in terms of terminal nodes, master controller node and monitoring software. nRF9E5 is used as the main control chip of the terminal nodes and master controller node, and the module of hardware and software are designed respectively. The hardware of terminal nodes includes DS18B20, HM1500 and Solar power circuit. The software of terminal nodes consists of three programme for wireless RX/TX, DS18B20 and HM1500. The hardware of master controller node is composed of EDM1079, USB130 and power supply module. The software of master controller node includes applied programme for EDM1079 and USB130. To solve high bit error rate in the wireless communication, the frequency hopping technology is used and a effective point to multi-point protocol is also developed. The functions of monitoring software include data acquisition and manage, graph display, person-machine dialogue, real-time database storage and ODBC database management.Applied in a agricultural zone of technology and science in Zhenjiang, the system shows better performances. Terminal nodes and master controller node can communicate well when distance is less than 80 meters. It also has several functions including real-time monitoring, data acquisition, data management and so on. With excellent generalization and scalability, the system will be populized in the future.