Design Of Intelligent PROFIBUS-DP Slave Based On USB Interface

According to the features of Universal Serial Bus(USB) and PROFIBUS, this thesis illustrates the design of an intelligent PROFIBUS-DP slave based on USB interface, by which, the Multifunctional system for Process and Control Experiment could communication with industrial system equipped with DP interface such as PLC and DCS instead of traditional AD/DA data acquisition card.Based on the nature of this thesis, the USB technology is introduced in the first sections including bus architecture, data flow model, data transfer types and so on, and then the design of the intelligent DP slave is discussed in detail from three parts: hardware, firmware and application program design. In the part of hardware, the thesis describes the hardware scheme of the DP slave system firstly, and then gives the practical recommendations on PCB layout and hardware debug according to experience. In terms of the firmware design, the framework is introduced, and followed by the detailed communication and data frame process between CY7C68013A and DPRAM module. The last part introduces some key data structures first, and then the functions that operate over Data Gate and USB device, and finally the multithread technology adopted in the application program.The last chapter gives the connect steps between the DP slave and SIMATIC PCS7 host, and ends with the performance test analysis. The experiments prove the fact that the intelligent slave can meet the communication requirement.