The Design Of Remote Monitoring System Based On Virtrual Instrument And Modbus

With the development of computer, communication and control technology, Control system is developing towards the signal digital, control intelligent, communication network open system. Fieldbus and network are more and more widely applied in industrial control area, Modbus fieldbus is a technology which efficiently supports distributed real-time with a very high level of security, It attracted attention with a very high level of capability and security and a very better of anti-jamming and a low maintenance cost and a particular design. Therefore, the development of measurement and control system based on Modbus fieldbus is full of significance.After researching Virtual Instrument and fieldbus technology, a remote monitoring system based on the integration of these two technologies was put forward in the thesis. The system getting help from fieldbus can bring about distributed monitoring, and that can make VI technology be applied in the large monitoring system. Simultaneously, Fieldbus Control System combined with VI technology can supply unified and friendly human-machine interface, and can achieve the aim of remote monitoring easily and fast. This kind of system can meet the demand of muti-network combination. This is the innovative point of the paper.S7-200 PLC was elected as measurement and control device. On the basis of introduction of the communication principle between PLC and PC using Modbus protocol, the thesis lays special stress on expounding the design ideas and implementation of PLC and PC communication program based on LabVIEW in detail. Besides, in the thesis, the technology of TCP/IP, Remote Panels and DataSocket also are described. We developed the remote monitoring system based on Remote Panels technology, and the system the system achieved the aim of data transmission and sharing and remote monitoring.Finally, the system was used in constant pressure water-supply. After analyzing the construction and function architecture of the monitoring system, we planned and accomplished the hardware configuration, and finished the program and testing running of the system. According to the performance, the system has exerted all strong function of fieldbus as the bottom information network of enterprises and the advantage of graphical language of Virtual Instrument, has optimized the control, improved the efficiency. The system achieved the aim of remote monitoring on the whole.