The Embedded System Hardware Platform Based On PROFIBUS-PA Protocol

Fieldbus is the new generation of industrial automation control system with information digitization,control decentralization,and open interoperability. However,the Ethernet and TCP/IP has become the first choice about network communication technology in IT industry.With the idea that the network is control receiving widespread approval more and more,the Ethernet and TCP/IP technology gradually obtain applications in automation industry and become one tendency.Under the background,the writer has conducted research to the communication between the Ethernet and the PROFIBUS PA in the subject of "The Embedded System Hardware Platform based on PROFIBUS-PA protocol".The paper introduces the PROFIBUS protocol briefly,and conducts research and analysis to the data link layer carefully.Then the new way of application of PA device is proposed.Based on the analysis of functional requirements,the paper has built the hardware platform with ARM chip as the core,which is the communication medium.Especially,a dedicated Modem chip of SIEMENS is used in the interface of PA bus.After the platform having been completed,the paper makes a in-depth study about the embedded operating system——μC/OS-Ⅱ,and transplants it under S3C44B0 successfully.The transplantation ofμC/OS-Ⅱcontributes to the achievement of multi-task scheduling.In order to meet the functional requirement of network,the writer selectes a suitable embedded TCP/IP protocol stack——LwIP,and completes the jobs of transplanting it to theμC/OS-Ⅱ.Finally,the application program is finished.The tasks are scheduled by the priority. Then,the system has been verified in experiment of PA in the laboratory.The paper points the questions and flaws,as well as the further study.