Profibus fieldbus network - technology overview

PROcess Field BUS

Profibus is the leading industrial communication system for manufacturing automation in Europe with strong growth in many other markets. Profibus is supported by Siemens and is promoted by the Profibus User Organization. Profibus products are certified by the Profibus User Organization (PNO), guaranteeing worldwide compatibility.

Profibus was originally defined 15 years ago under the German standard DIN 19245 and is today part of the international standard series IEC 61158. Based on the initial functionality, many new features have been added and today, Profibus consists of a family of 3 protocol variations (DP, DPV1, DPV2) that can be used with different physical transmission media.

Device Profile improve interoperability
In addition to the protocol definitions, Profibus defines many Application Profiles for specific device types and industries i.e. ProfiDrive for Drives, Profibus-PA for Process Automation and ProfiSafe for Safety Applications. Profibus features real time transmission capabilities, flexible network topologies, advanced data access procedures, good diagnostic concepts and proven configuration mechanisms.

Profibus Protocol Family
Profibus is a Multi Master Network. Depending on the selected protocol variation, it supports Master/Slave, Master/Master and Slave/Slave communications. Profibus is optimized to transmit cyclic process data very fast and efficient between Master and Slaves but can also handle acyclic Parameter data and iso synchronous Real time transmissions.

Version DP-V0
Provides the basic functionality of DP, including cyclic data exchange, station, module and channel-specific diagnostics and four different interrupt types for diagnostics and process interrupts, and for the pulling and plugging of stations.

Version DP-V1
Contains enhancements geared towards process automation, in particular acyclic data communication for parameter assignment, operation, visualization and interrupt control of intelligent field devices, parallel to cyclic user data communication. This permits online access to stations using engineering tools. In addition, DP-V1 has three additional interrupt types: status interrupt, update interrupt and a manufacturer-specific interrupt.

Version DP-V2
Contains further enhancements and is geared primarily towards the demands of drive technology. Due to additional functionalities, such as isochronous slave mode and lateral slave communication (DXB) etc., the DP-V2 can also be implemented as a drive bus for controlling fast movement sequences in drive axes

Configuration with GSD-Files
During the setup phase of the Profibus network, the Profibus Master must be configured with a special configuration tool such as Step7 from Siemens or NetTool from HMS. The configuration process is based on electronic device data sheets (GSD-Files) which are required for each Profibus device. GSD-Files are provided by the device manufacturer and contain electronic descriptions all relevant communication parameter of the Profibus device.

PROFIBUS FACTS
Network Type:	Multi-Master/Slave Communication system
Topology:	Depending on physical media RS-485:  segmented line topology without stubs Fibre Optic: Star or Ring topology MPB:  segmented line topology with stubs
Installation :	Shielded twisted pair cable or Fibre optic media Power over the bus and intrinsically safety with MBP possible Line length depending on physical media and transmission speed
Data Rate :	9,6 kbit/s up to 12 Mbit/s (selectable)
max. Stations:	Up to 32 stations (Master or Slaves) per Segment Up to 126 stations per network
Data :	Each Slave:  - max 244 Byte cyclic Input and 244 Byte Output data                        - additional 240 Byte acyclic Parameter Data Total:             - 30 kByte cyclic I/O data plus acyclic Parameter data
Network Features :	Advanced Multi Master communication system for factory, process and building automation.
User Organization:	Profibus International

HMS is an active member of the Profibus User Organization and participates actively in the further standardization of the Profibus technology. HMS offers a broad range of certified Profibus products.