Abstract
Fieldbus technology is the late 80s, early 90s formed the international development for process automation, manufacturing automation, building automation and other fields of on-site communications network interconnecting smart devices. Factory digital communications network as the foundation of the production process of communication and control equipment on site and with more control and management between the level of links. It is not only a grassroots network, but also an open, new full distributed control system. The intelligent sensing, control, computer, digital communications technology as the main content of the integrated technology has been worldwide concern, the development of automation technology to become hot, and will lead to automation systems and equipment of the profound structural changes. CAN bus is a fieldbus, the data communication with high reliability and flexibility of real-time strong and good, is now considered the most promising one of the fieldbus. Greenhouse climate affected by various factors. Complex and numerous, difficult to be fully calculated. View of the current situation and characteristics of the greenhouse system, decided to use current technology more advanced field bus control. History and overall system design framework for the various growing areas to control by an intelligent node, nodes connected by field bus to achieve decentralized control, then access to a computer as a human-machine interface, the implementation of supervision. According to modern greenhouse control requirements, design an appropriate application of fieldbus technology, greenhouse control system. This article reference in the access to a large number of domestic and international basis, an overview of the history of the greenhouse at home and abroad, and current condition. Introduced the domestic and international greenhouse monitoring and control devices and Fazhan direction of developments, and based on the greenhouse environmental factors affecting crop growth, namely, temperature, humidity, light and other environmental of the conditions, Kong Zhi characteristics and control method, suitable for the system proposed by the environmental factors control program. In this paper, Philips Semiconductor as an independent controller SJA1000, SJA1000 achieved by controlling the data communications tasks such as receiving and sending. 89C51 microprocessor used as a node, the bus transceiver 82C250. This article focuses on the greenhouse environment control system hardware. This design idea is to meet the system requirements of the premise, as far as possible use low cost, low power consumption components, to achieve lower system costs. Finally, the actual operation of the project, the application of CAN bus technology, modern greenhouse control system was eva luated on a summary of my work and looking forward to a bright modern bus technology applications. Key words: greenhouse environment control system microprocessor SJA1000
