Research And Design Of Network Instrument Based On CAN Bus And Linux

The emergence of the field bus completely changed the structure of traditional industrial control systems, which allows for development in the direction of network, intelligence and decentralization. By using fieldbus as a nexus, fieldbus control system converts single distributed surveying control equipment to a node in network, they can communicate with each other and finish automatic control task together.Based on the analysis of the characteristics and system structure of fieldbus control system, and to meet the demands, this paper uses CAN bus which is one of the most promosing fieldbus to construct network system, and proposes a solution to establish a reasonable, intelligent, stable and reliable network instrument system. And based on ARM and Linux, this program designs a master station. This paper explains the details of the work done in this program from the aspects of hardware, software and system application layer protocol.In terms of the hardware design, using module design method, a master station which includes a minimum system module, external interfaces, LCD module and a CAN interface is designsed in this paper, and the CPU of the master station is S3C2440. In terms of the software design, a description of how to establish the embedded Linux OS in the ARM system. The paper focuses on how to design CAN device driver in Linux system, and describes how to use the QT platform to write application programs in Linux. In addition, this paper has constituted a reasonable, simple, and convenient application layer protocol, which is not only one of the paper's key points, but also an innovative point.The ARM with Linux hardware platform development technology discussed in this paper also has reference value to other embedded system development. Besides, by self-defining CAN bus application layer protocol, this program solves the problem of network communication in intelligent instrument network systems. Therefore, this protocol is of great significance for small and medium-sized field bus systems.