本文给出了一种由MCP250505 构成的无需外加CPU 的CAN 总线节点的设计方案,介绍了CAN 总线网络节点的硬件设计和软件设计,并对MCP25050 的特性以及相关协议作了详细分析。实验表明,该系统具有结构简单、可靠性高、使用灵活方便、性能价格比高等特点,在分布式数据采集和控制中具有广阔的应用前景。 关键词: CAN;现场总线;MCP25050;网络节点 Abstract : This paper presents a kind of design scheme for distributed measure and control system based on CAN bus with CAN I/O expander MCP25050. A hardware design for main node and the CAN bus interface are proposed, and the overall architecture, hardware configuration, software functions are discussed in detail. It is indicated through experiment that the system is simple, reliable and cheap for CAN bus application. Key words: Field bus; CAN; Measure control node; Distributed control