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In this paper, based on analysis of the status of development of the domestic and international electromagnetic flowmeter, comprehensive application of the new microprocessor, computer hardware and software and fieldbus technology, developed set of electromagnetic flow sensor converter based on CAN bus intelligent flow totalizer meter in one instrumentation systems. To meet electromagnetic flow detection instrument and system development needs, enhance system openness, reliability, and communication functions, for the first time the CAN bus technology applications to electromagnetic flow instrumentation system, improve our electromagnetic flow detection technology level of positive significance and importance application value. Hardware implementation, the proposed programmable excitation of new technologies, while the small-signal amplifier, V / F conversion, automatic range switching, power monitoring and power-down protection and CAN communication interface circuit is analyzed in detail and design. System software development, a reference to the Windows message-driven program design thinking to build the the microcontroller system software architecture of new ideas, based on this idea of ??the project control software architecture, development of specific software function modules. Finally, the project system assembly and test, and summary and outlook. The first chapter reviews the history of the development of the electromagnetic flowmeter technology developments and application status the fieldbus instrumentation systems the causes, characteristics, development trends and the role of. Finally, according to the electromagnetic flowmeter development status at home and abroad and the actual needs, the argument developed based on the necessity and significance of the CAN bus intelligent flow instrumentation system and given the research content and the overall arrangements. The second chapter describes the basic principle of electromagnetic flowmeter and CAN bus technology base, the analysis focuses on the characteristics of the CAN bus protocol hierarchy, technical specifications, packet transmission, frame structure and CAN bus interface electrical connections related technologies, etc. The third chapter of the content based on the practical application of the project as well as user requirements, project task analysis to determine the design principles, electromagnetic flow meter system development involves analysis, research, compare and argumentation proposed programmable excitation of new technologies to determine the technical implementation of the program adopted by the various functional modules of the system, based on CAN bus intelligent the integrated electromagnetic flow instrumentation system overall structure, and analyze the role of the various components of the system. Chapter IV describes the system design task, design principles, as well as the overall design of the program priorities small signal amplification circuit, analog-to-digital conversion, programmable excitation technology, automatic range switching circuit design of the functional modules of CAN communication interface and system anti-jamming hardware. The fifth chapter describes the background of the message-driven ideas generated on the Windows message-driven works, the proposed reference to the Windows message-driven program design thinking to build SCM system software architecture of new ideas, and in this thinking, under the guidance of the project software development architecture, development of the project software function modules. Chapter VI system assembly and test trials on the basis of previous work. Chapter VII of the full text of the work summary and outlook.
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