Development Of Dual-Redundant CAN Bus Module

Field bus is a connection network between the controller and measurement device at the production site. Now there are more than ten kinds of field bus which are recognized, the CAN bus is also one of them. Because of its high reliability, low cost, stability, etc, which are widely used in control areas liking automotive, electrical, mechanical, chemical, aerospace. However, it requires highly reliable data transfermation and bus management in the field of aerospace. While the CAN protocol cannot meet this requirement, thus it is necessary to design higher-level protocol and hardware design.The dual redundant CAN bus module based on NIOSII processor is designed in this paper. It proposed the dual redundant CAN communication protocol, which supports this module, through the CAN protocol, 1553B protocol and redundancy analysis. The protocol uses the CAN bus of extension frame to achieve the bus management and flexible switching bus.In dual redundant CAN bus module, it is designed by the NIOS II processor embedded in FPGA, It selects SJA1000 as the CAN controller and TJA1000 as the CAN transceiver. It achieves communication between NIOS II processor and the peripherals through Avalon interface module connected. Including communication between NIOS II and the CAN controller SJA1000, or SRAM, or configuration chip EPCS4 of FPGA.According to the dual redundancy protocol, Nodes on the bus contain master nodes and slave nodes, NIOS II processor for modular programming is done in eclipse integrated development environment to achieve communication between nodes and make the master and slave nodes finish their respective functions. The master node is mainly used to send commands or data and error handing. The slave node is mainly used to receive commands or data and response back to the master node after completion of the implementation.Using three dual redundant CAN bus module to build a test platform, a module as the master node and the other two modules as a slave node. Experimental results show that the hardware design and the software design is reasonable in the dual redundant CAN bus module which is proposed in the paper, having implemented redundany.