A Development And Approach Of PROFIBUS-DP And HART Protocol Conversion

The birth of fieldbus results in deeply transformation in traditional control systems. However, the large number and dis-compatible fieldbus protocols paralyze the application in the plants. Therefore, have a study on the interconnection method of different fieldbus systems will be of great practical significance. A gateway design scheme is brought up in this thesis, which realizes the interconnection between two widely used fieldbus systems —PROFIBUS-DP and HART (Highway Addressable Remote Transducer).According to ISO/OSI reference model and combing with the characteristics of fieldbus protocol, the structures of PROFIBUS-DP and HART are analyzed layer by layer. The conversion method between DP and HART is proposed with the results of the analysis. The development of software and hardware for the gateway is realized as the result.The hardware structure of the gateway is a double CPU structure based on Intel 80C52 series MCU that worked independently. For the purpose of raising reliability of PROFIBUS-DP communication and saving time of the development process, the ASIC SPC3 is used for the realization of the DP communication function and the HT2015 is used for the realization of the HART communication function.The development of the main program (the program worked in the main CPU that controlling the PROFIBUS-DP communication) is based on the DPS2 software package provided by SIEMENS. The main program is used for the controlling of SPC3 and the whole controlling the gateway. And the slave program is used foe the controlling of HT2015 that take charge of the communication of HART.The gateway is both up to PROFIBUS-DP standard and Bell 202 standard of HART protocol. In addition, it supports the most common functions of HART for its flexible uses. With the use of the gateway, the interconnection among SIMATIC S7 system, SIMATIC WinLC system and HART slaves is realized under testing conditions. The testing results testified the correctness the protocol conversion method proposed in this thesis.