The Study Of PROFIBUS-DP Fieldbus Slave Station

Field bus technology is in the state of continuous development, there have been a lot of field bus standard, and Profibus field bus is one of the field bus is widely popular today. Profibus field bus has three kinds of forms: Profibus-DP(Decentralized Periphery), Profibus-FMS(Fieldbus Message Specification),Profibus-PA(Profibus Automation), where Profibus-DP is widely used because of its flexibility and reliability are in the range of the world, is widely used in high-speed data transmission of sensor and actuator, and the communication between the central controller decentralized field devices. But the current Profibus-DP equipment based on foreign and domestic independent research and development, the interface is very small, and not every equipment can be connected to the Profibus network, which makes industrial equipment development Profibus communication interface is very important. Based on the above characteristics, this paper puts forward the design based on Profibus-DP field bus interface circuit.This paper first introduces the field bus as well as the status of Profibus-DP at home and abroad, the development prospects, pointed out that the development of Profibus-DP in China and its limitations, a systematic exposition of the Profibus-DP field bus protocol, each layer of the Profibus-DP field bus is analyzed, also illustrates the use of communication in the process of message transmission protocol.Considering the characteristics of Profibus-DP from the base station interface circuit, the ARM chip STM32F103 to realize the scheme based on Profibus-DP field bus; then from the hardware and software part of the station interface circuit design, including the core device is introduced, the hardware principle diagram of each module design, software programming and GSD programming. The hardware mainly includes power supply design, ARM chip STM32F103 and Siemens protocol chip VPC3 connection, RS-485 communication interface design. In addition, also proposed the communication interface circuit design of concrete without mutual interference of two voltage power supply, high communication speed etc.. The software mainly completes the physical layer and data link layer function, interrupt program module and GSD module software design and realization method of the main program module, are given. Finally, to test the circuit, using the S7-300 as the main Siemens, using the programming software STEP 7 to program the development of slave station interface module for communication function test, and simulate the master to get the message of the test process, and analyzes the test results of the received message, so that the communication between the master and slave the circuit design can meet the demand of communication.In this paper, Can use hardware to achieve communication protocols, making programming simple, can realize the communication function of high speed ARM chip development, communication interface circuit, which can realize the normal communication between master and slave.