A Study And Application Of An Adaptive Baud Rate HUB Module Based On Profibus.DP

Profibus.DP(Decentralized Periphery) is a high-speed optimized communications connectivity, is specifically designed for I/O between automation control systems communication and I/O equipment level communication. It can be applied to data distributed control system. As a connecting device between physical layer and data linking layer of network, HUB’s major function is to serve as a communication module to link master control with I/O in the field of data /physical layer /communication. Through the choosing of different passages to data signal transmission and the controlling of switches, the link and even the equipment cabinet can be expanded, then the number of I/Os and other devices will be improved. In addition, HUB module complete division in network, the electronic isolation between superior and subordinate in network and fault isolation function become true, as a result, it can prevent the whole system breakdown caused by spreading of a fault.This design is based on the basic function of HUB module, and based on Profibus.DP protocol. Firstly,it is needed to complete the function of circuit simulation, to determine the layout and design direction. Then with the help of PADS, Keil, Quartus etc. and the actual hardware circuit debugging and experiment, I completed the HUB module designing and the realize the function of HUB module for the DCS system of physical connection and data transceiver function. Finally I tested functions of the module, debug and improve the hardware and firmware.What’s more,the HUB module realize monitoring the environmental temperature, and field power supply to make the module having more application value.