【作者】 王彬；

【导师】 和卫星；

【作者基本信息】 江苏大学 ， 电力电子与电力传动， 2002， 硕士

【摘要】 在工业过程控制领域,以微电子技术和网络技术为基础的现场总线,正处于迅速发展和推广应用的阶段。本课题以社区用电远程抄表系统为对象,对CAN(Controller Area Network)总线智能节点和CAN总线控制系统进行设计开发。在提高企业的自动化水平,减少设计费用,增加系统运行的可靠性等方面,做一些前期的理论和技术工作。本文首先分析FCS的优缺点,对FCS的发展和现状进行回顾和调查分析,并对现有几种主要的现场总线规范进行比较。在此基础上,再根据具体对象——远程抄表系统的特点,选择适用于中小型控制系统的CAN总线与RS232、RS485进行组网,搭建成一个结构简单、功能较强、易扩展的控制系统。本课题的具体工作是设计CAN/RS485转接盒(集中控制器)、CAN-RS232转发器和管理中心主机的监控管理软件。其中,CAN总线接口的硬、软件设计是本课题的重点。在详细研究CAN总线工作原理的基础上,利用CAN独立控制器SJA1000芯片,实现CAN/RS485和CAN/RS232两个转发器,并开发相应的管理控制和网络通信软件系统。在管理PC机上,利用Visual C++6.0高级语言,开发相应的小区电量计量和收费管理系统的可视监控软件,实现现场总线控制系统的主要功能。从硬、软件方面,对智能控制器进行多种可靠性和抗干扰性设计,诸如光电隔离、去耦合、看门狗、后备电源、设置软件陷阱等方法。另外,系统采用模拟I~2C串行总线,以优化单片机系统设计,减少单片机与外部器件的连线数量。课题工作中,实现了实验性的基于CAN现场总线控制系统。总体看来,这套系统具有较高的可靠性、连接方便、硬件结构简单、性价比高等特点,适用于一般的场合,但要实现产品化,还需做许多细致的工作。更多还原

【Abstract】 In the field of industrial control, the fieldbus, which is based on the techniques in microelectronics and network, is now undergoing a fast development and wide application. On the basis of the system of transmitting remote meter data, the study is mainly concerned with the design of a measurement & control node in CAN (Controller Area Network) and a CAN network control system.The advantage and the disadvantage of FCS are analyzed. Comparison is made on the present fieldbus systems. Then, considering the object, the CAN bus is selected to complete the control system together with RS485 and RS232. Because CAN bus is more suitable to mid and small sized control systems.The duty of the study is to design the CAN/RS485 controller, the CAN/RS232 controller and the visual monitoring software. The hardware and software design of the interface to CAN bus is the focus of the study. On the basis of a comprehensively study on the principles of CAN bus, interfaces of CAN/RS232 and CAN/RS485, is realized with SJA1000 Stand-alone CAN Controller, as well as the corresponding network communication software. And the corresponding visual monitoring software is designed with Visual C++, realizing part of primary function of FCS.Taking account of heavy disturbing environment factor, many methods are adopted in controllers, for example, optoelectronic isolated circuit, removing coupling circuit, watchdog circuit, backup power, and so on. The simulated serial bus of I C is used in the control system, in order to optimize the design of single-chip microcomputer system and achieve connection between single-chip microcomputer and external apparatus using lesser line.An experimental FCS based on CAN bus is realized. In total, this system features high reliability, feasibility, simplicity, high performance/price ratio, and so on. But, in order to coming into being series of CAN products, there is much particular work to be done.更多还原