The Application of ModBus Protocol In Industry Control System ZhuYi,Jiang,NianPing ( School of Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093) Abstract: With the development of internet, communication and control techniques, the domain of information communication and exchange has been covering from the layer of equipment to the layers of control and management. It is of great importance for the popularization and application of Fieldbus in our country to develop the digital meter based on Fieldbus.In the article,I firstly introduce the ModBus,then I design a temperature-control system. Key words:FieldBus;ModBus Protocol;MCU Control