Research And Design Of Multi-channel Data Acquisition Device And Intelligent Instrument

Current measuring instrument less than three-phase cannot meet requirement for multi-channel data acquisition in home electric power monitoring field. Compared with high-speed developing intelligent instrument technology, the function, measuring speed and precision are relatively backward.Although many various multi-channel Data Acquisitions have been developed, they are used mainly in civil pulse kilowatt-hour meter, water meter, fuel gas meter and heat energy meter. As a result, this paper develops a new type of multi-channel Data Acquisition based on ATmega128, which can measure AC current, monitor the information of alarm and state, and combine with personal computer control and long-distance control.By thorough studying the design method of intelligent instrument, this thesis analyses functional requirement of multi-channel Data Acquisition, and proposes feasibility design method. The thesis'main content: (1) It discusses about developmental process and trend of intelligent instrument, introduces method which includes hardware designing and software programming based on constitution of intelligent instrument included input, output, man-machine interaction and communication interface, then discusses about principle and theory of multi-channel Data Acquisition System. (2) The thesis details on hardware designing and software programming, solves measuring problem, and explains anti-interference technology which should be paid attention to in the designing process. The specific subject of the thesis is hardware designing and software programming of data acquisition part. Its hardware designing realizes analog input/out and communication interface, which center around AVR high-speed embedded single chip computer. By thorough software programming, it achieves data acquisition of eight-circuit AC current which makes rounds dynamically at high speed. At the same time, it accomplishes communication between personal computer and instrument by using Modbus/RTU as communication protocol.The new type of multi-channel Data Acquisition has been developed based on AVR high-speed embedded single chip computer. It can directly be used in the enterprise in home electric power field. It will greatly reduce cost and improve speed and precision of measuring parameter. The sample has been completed and passed relevant official department appraisal. A large number have been produced and used.