The Design Of The Safety Monitor System Based On Centralized And Distributed Fieldbus

In China, there are a large number of hydropower stations under construction or will be built. Accidents occurred on the dam will not only affect the normal construction and operation, but also cause property losses, in some cases may even lead to social disaster. Safety monitoring plays a very important role in the design, construction and operation of dams. And the safety monitoring in slope of the dam occupy an important position in the whole safety monitoring system.This thesis designs a safety monitoring control system of dam slope, which will be used in Laxiwa hydropower dam in Qinghai Province. The whole system includes the bottom measurement modules, the upper software of Human-Computer Interface and communication program. I am mainly responsible for the bottom measurement modules'and repeaters'hardware and software design.C8051F040 is used as a measurement control module core. It can always monitor a variety of sensors at a high-precision online, and also carrying long-range, reliable data transmission through the CAN bus in it; Repeater is designed by two CPUs, which use SPI bus to communicate with each other in order to ensure the accuracy of long-distance communication and speed.Concrete work is as follows:(1) The design of hardware and software for the bottom module makes the system to obtain a high accuracy and good real-time; besides, the temperature calibration for the modules can ensure the measurement accuracy at a whole range of the temperature.(2) By using the serial parallel converter chip, the system can measure much more sensors at the same accuracy, reduce the cost of hardware. At last, the system achieved the miniaturization.(3) Repeater is designed to ensure accurate communication with the PC, increase the load capacity of the system. A new system is formed by (1) to (3).It mainly used in large-scale and long-distance monitoring system for water systems, its characters is: the nodes have CPU, analog bus driver and control bus inside of them,the node use the CAN fieldbus to connect with the others.(4) A large number of experiments were done on the system. We analyzed the causes of all kinds of errors, and given the specific method to a solution improve the measurement accuracy of the system.The system has been basically completed in the laboratory. It can reach the national standard of water system requirements of precision in the laboratory experiments. It is about to being tested in the locale.