PROFIBUS Manual

PROFIBUS defines the technical features of a serial field bus system, by which distributed digital automation devices, from field to cell level, can be networked together. PROFIBUS is a multi-master system and so allows the combined operation  on one bus of several automation, engineering and visualization systems with remote peripherals. PROFIBUS achieves this by differentiating between various device types.

PROFIBUS is based on recognized, international standards. Protocol architecture follows the OSI (open system interconnection) reference model, according to the international standard ISO 7498.

The standard requires each layer of transmission to take on precisely defined tasks: layer 1 (Physical Layer) defines the physical side of transmission , layer 2 (Data Link Layer) defines the bus access protocol  and layer 7 (Application Layer) defines application functions. Application profiles (User Layer) determine how communications functions should be used in different device classes and applications.

Structure according to the OSI reference model

PROFIBUS offers different services for automation technology: cyclic data exchange  for process data and acyclic data exchange  for parameter setting data.