Design And Realization Of CAN Analyzer Based On USB And Performance-analyzing Software

The CAN bus is one of the field busses widely used in industrial control. In the development of a CAN bus, it is very necessary to verify the effectiveness and real-time performance of the CAN system using an experimental platform and testing tools. In order to perfect the CAN bus experimental platform developed by the study team, they engaged in research on the CAN analyzer and used off-line performance analysis software.The CAN bus analyzer chosen used a 32-bit ARM AT91RM9200 micro-processor with a USB controller as the core, with an extension MCP2515 CAN controller, and FLASH and SDRAM storage. The AT91RM9200 and MCP2515 were connected using the Serial Peripheral Interface (SPI). The content of the SPI interface and the programming of this is introduced. The general circuit diagram is shown in this thesis also.The design of the CAN bus analyzer software based on the USB is detailed in chapter 2. In order to realize real-time transmission of the CAN frame and the capture of the time-stamp, problems such as the choice of PDC channel, TC channel and the receiving of the CAN frame were solved and verified by experimentation. According to the features of the CAN protocol, the thesis that CAN is an asynchronous protocol is put forward in the initial design of the MCP2515, and the synchronization mechanism of CAN is analyzed in detail. The transplantation of firmware, the design and implementation of the data upload package and the establishment of a display interface are described with the AT91RM9200 as a USB device.The design of off-line performance analysis software is based on the data format generated by CanAnalyser/32. The show of curve of load rate, ID density, data trend and correlative performance parameters is realized in the display interface. (See Note) After testing the data collection in the CAN bus experiment platform, the validity of this software was proven.It should be pointed out that this thesis only completes fundamental work. Many other problems, such as CAN frame uploads using the USB interface, graphic interface rolling equably with time etc, need further research.