The Design And Development Of Modbus And CAN Bus Protocol Adapter

Field bus technology is the research hotspot of automation development now. CAN bus as a reliable, functional, flexible and advanced remote network control method which at a reasonable price, has a very wide range of applications in the industrial automation and control area. MODBUS statute enables the definition of the application layer in OSI reference model, usually as the network communications for instrumentation layer.In the present circumstances, most of the field intelligent instruments and meters, and other automation control devices commonly adopt Modbus serial interface communication protocol. However, the MODBUS statute and the CAN bus protocol are incompatible. The devices which adopt MODBUS statute can not be access to the CAN bus network.In this paper, we design a simple and capable of intelligent protocol adapter both from the software and hardware set based on studying the MODBUS and CAN bus, achieving the reliable and high-speed conversion between the Modbus bus protocol and CAN bus protocol in an intelligent mode. The devices which adopt MODBUS statute can access to CAN bus network through Bus Protocol Adapter flexibly.According to the poor working conditions of Bus protocol adapter, the reliability and anti-jamming capability of bus protocol adapter can be enhanced from both the hardware design and software design.This article also describes the laboratory tests as well as analysis of the results. Provide data foundation for the work performance of Bus Protocol Adapter.The practical significance of this issue lies in the implementation plan of intelligent bus protocol adapter which made Modbus bus and CAN bus network compatible. It enables most of the field intelligent instruments and meters which adopt Modbus serial interface communication protocol and other automation control devices to access to the CAN field bus network flexibly. The described application method can also provide a reference for other areas of the IPC.