Research On Communications Of PROFIBUS-DP Fieldbus And Design Of Intelligent Slaver

Many technologies such as digital communication technology, computer technology, automation and control technology, network technology and intelligent instruments technology are integrated into the Fieldbus. Fieldbus control system constitutes the distribute, digital, intelligent, two-direction, interlink, multi-parameters, multi-point communication and control system, and becomes the trend of the development of automation and control. PROFIBUS is more popular among all existing Fieldbus standards, and PROFIBUS-DP, which is used in the control system of device-level and distributed I/O communication, is the market leader in Fieldbus technology. At present, the applications and researches on PROFIBUS-DP in our country are mainly the whole set of equipments produced by Siemens and so on, while the communication interface developed and researched independently is very few. So it is obviously especially important to develop PROFIBUS-DP communication interface for instruments and electric apparatuses, so that the indigenous equipments are able to be connected to the PROFIBUS, and this certainly will push the intellectualized course of the instruments industry and push the applications of Fieldbus in our country. Exactly according to the current status of Fieldbus development and application in our country, this paper presents software/hardware design and implementation method of PROFIBUS-DP intelligent slave station interface based on studying the basic theory of PROFIBUS-DP (including system composing, protocol structure, data access mechanism and slave station communication principle). By using the PROFIBUS-DP protocol chip and MCS-51, the module of the intelligent slave station interface with PROFIBUS-DP interface, which is used for digital input and output, has been developed. And using the CP5611 as the master station, combining with the module of the slave station interface to compose the minimum system of PROFIBUS-DP, which includes the single master station and single slave station. Based on this system, to test the module of the intelligent slave station interface developed. Finally, this paper summarizes the whole work of the task, and brings forward the further research direction and approach for the development and system integration of PROFIBUS-DP intelligent slave station interface.