The company Power-Line Communication IT Solutions Field bus systems Interbus Profibus CAN Railway equipment Electronic engineering Documentation and translations Quality management Contact us! Customers entry Glossary Impressum Profibus Profibus bus was the first international, open producer-independent standard fieldbus for building, manufacturing and process automation (in accordance with EN 50170). There are three different versions: Profibus FMS (Fieldbus Message Specification) is appropriate for object-oriented data exchange in the cell and field area. Profibus PA (Process automation) fulfills the request of the process industry and can be used for the intrinsically safe and not intrinsically safe area. Profibus DP (decentral periphery) is for fast data exchange in the field of building and manufacturing automation. Structure A profibus system consists of one or more masters and one or more slaves, which are connected by bus cables and bus plugs. A bus segment consists of a maximum of 32 field devices. If more devices are necessary, it is possible to link more bus segments by using repeaters (signal amplifiers). At the end of each bus segment a termination resistor must be used. The number of slaves, which can be operated by a master, is dependent on the internal memory structure of the master. Up to 126 stations can be involved in the maximum configuration of a profibus system. The master is usually realized as a connecting module at the control system or as a PC interface card. Typical slave devices are sensors, actuators, transducers or display elements. Basic principle Profibus operates according to the master slave principle with token passing. The master regulates the bus traffic. The request of input data and the writing of output data between the master and slaves are performed cyclically. If several masters exist, the access right is regulated by the exchange of a token. Using a software configuration tool, a database is generated which contains the network structure with the necessary configuration and parameter data. The master accesses this database and transmits configuration data to the appropriate users when the profibus system is powered up. After this data is received and stored by the individual users, the system changes to ?data exchange? mode.

Last changes: 25.05.2010