The Development On Software Implementation Of Profibus-DP Slave By STM32F103

Profibus-DP which has a very high market share, is widely usedin equipment control system and distributed I/O communications. Thereare many advantages, such as, simple installation, real-time and reliablecommunication. At present, in China, the research on the communicationinterface of Profibus-DP is limited, and mainly bases on some foreigndevices. Domestic Profibus-DP slaves usually use ASIC-dedicatedProfibus chips SPC3which are produced by the German company,Siemens, However, the SPC3chip is so expensive that mostmanufacturers can’t afford the enormous cost and only a few productsemploys Profibus-DP communication interface. In contrast, STM32F103chips have many advantages, such as high communication rate, sufficienthardware resources, easy to transplant real-time operating system ucos-IIon and so on. In response to these points, this paper illuminates anadvanced program, which uses ARM7chips STM32F103instead ofSPC3, and combines hardware with software. Profibus-DP slave which in this solution is has some characteristic, such as low hardware cost, highcommunication rate, easy to modify and to expand, high flexibility, etc.The plan proposed solves the problem which Profibus-DP interface can’tbe widely used in China.We introduce the implement of Profibus-DP slave in thefollowing aspects.(1)Firstly, we summarize the development situation of thefieldbus and application prospect of Profibus-DP protocol both in Chinaand abroad. Then the research method in DP slaves and its limitationare discussed. Finally, we present this paper’s research plan, contents aswell as key technological problems that have not been resolved.(2)We compare various domestic programs’s advantages anddisadvantages, present an improved scheme using STM32F103chipsoftware programming, and perform a technical feasibility study onanticipative target.(3) We introduce the hardware and software design ofProfibus-DP slaves, and present schematic diagram design, PCB, weldingand debugging circuit and software program. The hardware circuit of thissystem is mainly composed of microprocessor interface, power supplyand RS485driver circuit. This paper mainly presents the design of MACand LLC layer, such as high speed data transmission, the frame intervalidentification, frame analysis, processing and packaging. (4)The DP slave test platform consists of a PC computer and aCP5611communication card which is used as the Profibus-DP master.On the platform, we can test if the DP slave achieved expected criterion.(5)Finally, the performed DP slave is tested to achieve howmuch packets are lost in the DP network using self-made loss rate teststation. Then, the given experimental data are analyzed in detail.The DP slave takes less fee in hardware than others which useProfibus chip SPC3. communicate with DP master in a high speed. So, itcan be widely applied to high-speed communication networks in theindustrial area.