Design Of CAN-Ethernet Gateway Based On ARM

At present, the local control network constructed by the fieldbus has been formed perfect technical system. With the development of control technology, the direct communication between field apparatus and managers of the enterprise has become a new research direction, and real-time sharing of production data and remote monitoring would be realized by this technology, which has great value and practical significance for the efficient management.There are many types of field bus, and CAN-Bus has advantages of good real-time communication, high reliability, strong network security, simple structure and low use cost, and it was widely used in industrial control field. But CAN-Bus also has some defects, such as CAN-Bus was subjected to the limit of transmission distance and transmission speed in actual use, CAN-Bus’ monitoring must be in the field. The maintenance of CAN-Bus was not convenient, which wasted the enterprise resources. But Ethernet had advantages of long distance, efficient transmission, always online, covering widely, rapid login, free switch etc. The CAN-Ethernet gateway was used to accomplish protocol conversion between CAN-Bus and Ethernet, which could ensure reliable transmission in long range of field data, it also provided a new idea for the management and control integration.32-bit processor LM3S8962was used in this article, which was based on the ARM Cortex-M3architecture, and IAR5.11was selected as developing software and compilers, and uC/OS-II embedded operating system was chosen. On the basis of analysis of CAN-Bus and Ethernet interface technology, this article designed a CAN-Ethernet gateway in order to achieve seamless connection of CAN-Bus and Ethernet.This article focused on the following aspects for discussion:(1) Based on structure characteristics of LM3S8962, many kinds of peripheral chips required by gateway were selected in this paper to complete the design and manufacture of gateway hardware system;(2) On the basis of in depth study CAN-Bus working principle and Ethernet communication protocol. In this paper, uC/OS-Ⅱ system kernel was transplanted, CAN bus controller and Ethernet controller driver were compiled, and LwIP protocol stack was clipped and transplanted, to realize the protocol conversion by writing application-level tasks.(3) Finally, the CAN-Ethernet gateway working performance was tested in this paper to realize the exchange of communication data, and the desired purpose was achieved by experiments.