The Research And Design Of Data Acquisition System Based On ModBus

The stable, economic and security electric energy supply system can support sustainable economic and social development. As an inseparable part of the social economy and people's life, the characteristic of the electric energy is continuous in its production and supply process, which requires the generators long-time safely and reliably working. Then it can guarantee the safety supply of electric energy, and can effectively support Chinese long-term economic growth.According to the problems about variety operation equipments and hard working conditions in the power system, we need real-time monitoring of the equipments, to ensure the normal operation of power plant continued days and nights. Because of the need monitoring power equipments being always in disperse positions, currently most power plants realize the monitor of temperature, pressure, flow rate about thermal parameters using theDistributed Control System. In view of the above problems, we designed a data acquisition system based on Modbus used in power plants, in order to collect the multi-point datas in the power plants, and the datas are transmitted to the Distributed Control System, monitoring the whole power plant at all time.We discuss research background and subject foundation, and analyse the data acquisition systems and their research status both at home and abroad , and the informatization, digital and networked development tendency of the data acquisition systems. Based on the introduction of the Distributed Control System in power plants, we also introduct the ModBus in detail. We finish hardware design and software realization of the data acquisition system with controller, and communicate through the bus with ModBus. This system can monitor most types parameters covering the basic general industry required monitoring.Finally, the data acquisition system take the actual testing, and the experimental results show that measurement precision of the system meets the design requirements. The data acquisition system based on ModBus currently has been used in power plants, and provides practical networking technologies for real-time control of data acquisition in the power plants, enhancing the accuracy and the stability of the data acquisition system, giving development of data acquisition system promoting and enhancing effect.