为了解决嵌入式WinCE平台上虚拟仪器软件开发的技术瓶颈问题——由于个人电脑和高级精简指令集计算机机器（advanced RISC machines，ARM）平台差异性，嵌入式平台下的虚拟仪器开发存在着控制器局域网络（controller area network，CAN）总线高速通讯、跨平台链接库调用等技术难题，该文在ARM11平台和WinCE操作系统环境下，对CAN总线通讯和虚拟仪器触摸板模块（LabVIEW touch panel module）进行了技术开发方法研究，介绍了嵌入式平台下CAN总线通讯机理及实现方法，开发了底层驱动和动态链接库，实现了嵌入式WinCE平台下 CAN 数据无缝链接交换关键技术。在此基础上，以中国农业机械化科学研究院研制的六行打包式棉花收获机为应用对象，开发了基于 CAN 总线的嵌入式虚拟仪器智能监控系统，并在新疆阿克苏地区阿拉尔垦区建设兵团农一师棉田进行了实地测试和功能验证，试验结果表明该虚拟仪器系统能够有效地实现多个 CAN 节点间的数据通信，可以完成对棉花收获机的工作状态在线监控和故障报警。该文为虚拟仪器技术在嵌入式平台上的应用提供了有效解决方法，对于大型智能机械装备自动化和信息化监控仪器开发具有指导和借鉴意义。%In order to solve the key problems generated in the development procedure of virtual instrument, this paper used controller area network (CAN) bus and LabVIEW touch panel module to develop virtual instrument based on ARM11 and WinCE. Because of the difference between PC and ARM platform, there are big problems in high-speed CAN data transmission and cross-platform call of dynamic link library (DLL). This paper mainly studied CAN bus communication mechanism and its implementation method, and developed the driver program and DLL in embedded WinCE system. And this paper made it possible to use LabVIEW virtual instrument technology in embedded WinCE platform based on CAN bus communication. LabVEIW graphical design environment not only accelerated the development process but also made it easy to make use of the real-time embedded operating system. There are hundreds of advanced signal analysis modules of LabVIEW, mathematical processing modules and rich human-machine interaction modules in LabVIEW touch panel module which insures the fast and friendly interface design and the powerful signal processing and computing process. This paper thoroughly introduced the implementation method of virtual instrument technology in embedded WinCE system and explained the call flow of cross-platform dynamic link library. To achieve the communication between embedded virtual instrument and CAN bus, this paper firstly developed the bottom driver program and the DLL suitable for Win32 platform and the DLL suitable for embedded platform. And then through the shared library block in LabVIEW, this paper achieved the advanced application of the DLL. At last, this paper finished the virtual instrument development based on the touch panel module in LabVIEW. The interface was well designed which looked very simple but practical. This paper has mastered the key technology of seamless link of CAN data. It took the six-row auto-pack cotton-picking machine as the object to develop an intelligent monitoring and controlling system based on CAN bus and embedded WinCE system. The field test was done in NongYiShi crop construction area of Alar, Aksu, Xinjiang The system achieved online monitoring and error alarming to the work state of cotton harvester. Apart from that, three functional verifications were also done. 1) Central controller can transmit collected data from data acquisition module and state monitoring module to the virtual instrument. 2) Through the touchable embedded virtual instrument interface, people can configure any node in CAN network. The configuration includes parameter setting, task allocation and so on. 3) This system can effectively detect the sensor fault and actuator failure and send the diagnosis messages to the customers. From the data provided by the field test we can see the advantage and promising future of virtual instrument based on embedded system. The system effectively realizes the high-speed CAN bus data communication among multiple CAN nodes, and the system has also strong flexibility and versatility, which can be taken as reference and guide in improving the automation and information level of large equipment in China.
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