Developing Intelligent Slave Station Base On PROFIBUS-DP

Field bus control system (FCS) is becoming the new generation control systemafter the distributed control system (DCS), which is one of the focuses in thecontrol field now. In multitudinous field bus standard, the PROFIBUS standardhas the merits of internationalization, opening, not depending on the devicemanufacture etc, which is becoming the object many countries study on. It isthe reason that this subject is selected.The intelligence slave station based on the PROFIBUS-DP bus protocol isdesigned in this paper. It is used on the behindhand equipments based on the4-20mA signal standard to connect the equipments expediently in the advancedPROFIBUS-DP field bus network.In this paper, the background of selecting this subject and the developmentabout this subject are introduced. Based on these, the characters of thePROFIBUS-DP standard and its protocol are discussed, the project of the hardwareand software system is put forward, the schematic diagram of A/D,D/A, realizingPROFIBUS-DP protocol redundancy, RS485 interface is designed. In the chapterof the software designed, according to the designing idea of modularization,all models and flow diagrams which the system needed are designed. The fixingRAM mode is chosen to communicate between modules. After the system finished,the PROFIBUS-DP master-slave communications network used to test theintelligence slave station is set up with the SIEMENS development-kit 4 and GSDfiles. The test has been successful, and the slave station designed cancommunicate well with the PROFIBUS-DP master-slave communications network.In the end, some design experiences are discussed, which may be helpful tothe research forward.