Design And Implementation Of Profibus Communication Monitor

Apply with the more and more extensive application of Profibus, installation, debugging and troubleshooting of Profibus control system becomes more and more important. Therefore, Profibus Communication Monitor based on PC is designed. It has great significance for maintenance, monitoring, detect and repair faults of Profibus system. So it is an indispensable and important tool. It can provide the on-line monitoring function, the real-time analysis function and the real-time processing function for a variety of devices which are accessed to Profibus system.Through analyzing the functional requirements for Profibus communications monitor in the practical application, and research Profibus communication protocol, this paper describes the key technologies in the development of Profibus Monitor, including telegram identification technology, telegram data analysis techniques, station scanning technology, and testing techniques for slave station; According to the needs in the application of monitor, it additional achieved telegram data storage and search function, condition triggering function, telegram filtering display function, etc.; The hardware circuit used AT91SAM7S64 ARM7 chip+ADM2486 chip to realize the conversion from RS485 bus data to USB data; The paper describes the design of the software and the implementation of each process in detail, and the monitor has been verified in the use of Profibus system.There were three points of innovation:(1) In the telegram identification process, using the method that different type telegram has different features to identificate telegram, this method solves the problem that the previous products can not meet the high-speed transmission in the bus; (2) In the telegram analysis process, provide the analy by bits for telegram specific data, this can get the specific information about the system easily; (3) Implementate the test function for slave through using PC instead of master, so this function can slove the slave test problem in the development process easily.