基于CANopen总线的开关信号板卡设计

针对传统PLC在分布式控制系统中的弊端，设计了一种基于CANopen总线的开关信号板卡，实现对工业生产过程中开关信号的实时控制，给出了板卡的软硬件设计原理，并且在仔细研究设备子协议DS401的基础上，重点结合对象字典阐述了CANopen中最常用的通讯对象PDO的通讯机理和实现开关信号输入、输出控制流程。另外，用概率方法对开关信号的状态采集部分进行了软件消抖处理；最后对板卡进行了通讯功能测试和分析，结果表明该板卡能进行可靠的数据传输，具有一定的实用价值，并且对CANopen总线的推广有一定的促进作用。

Design of switch signal board card based on CANopen bus

Focusing on the disadvantages of traditional PLC in DCS, a switch signal card based on CANopen bus is designed, which is used to control switch signal in the process of industry production. It gives the design principle of the hardware and software of the board card. On the basis of researching device profile DS 401, it emphasizes on the communication mechanism of PDO which is most common communication object in CANopen and the process of input/output of switch signal. In addition, using probabilistic method to deal with jetters of switch signal acquisition. Finally, functional test and analysis is conducted and results show that the card is reliable on data transmission, and has a positive impact on the promotion of CANopen.