Research On PROFIBUS-DP Fieldbus Monitoring System

PROFIBUS-DP(Decentralized Periphery)fieldbus occupies a dominant position in the field of industrial control.The number of fieldbus device nodes in the world has accounted for more than 40%.It is mainly used for data communication between automatic control systems and device-level distributed I/O.However,affected by the complex and changeable harsh environment of its application site,the status of the site itself and the data communication between sites are prone to failure,and it is difficult to troubleshoot in a timely and convenient manner.Estimating system risk and troubleshooting has important practical significance.In this paper,the network structure,communication principle,protocol structure,data access rules and message format of PROFIBUS-DP field bus are deeply analyzed,and the message frame extraction method of monitoring system is proposed.The mathematical model of the system provides a theoretical basis for the realization of various functions of the monitoring system.Developed a PROFIBUS-DP fieldbus monitoring system based on ARM+FPGA architecture,with the coordination of dual processors,to achieve site status monitoring,original message data acquisition,DP bus physical layer waveform acquisition,data storage and analysis,data transmission(available USB interface or Ethernet interface)and other functions,the system adopts the pluggable structure of base + card,which meets the actual technical requirements of miniaturization and convenient installation,and is also conducive to the expansion of functions.Finally,a test platform based on the HOLLi AS DCS-K distributed control system is constructed,and the functional verification,environmental adaptability test,and EMC reliability test are completed.The test results show that: the system can reliably collect site status information,bus physical layer waveform,and message data at the same time;the whole system can adapt to the working temperature of-25℃～65℃;RE,ESD,SURGE,EFT and PMS have been tested,and the results show that the monitoring system can meet the electromagnetic compatibility test standards.