Performance with PROFINET
A year ago, PI (PROFIBUS & PROFINET International) presented the results of a scientific study on the topic of communication performance with Ethernet. The results showed that in terms of complex machinery and plant structures, performance has always been significantly better with PROFINET than with all other systems. Additional performance potential was identified only for line structures in the case of very short frames. Already at its booth at the 2008 Hanover Fair (Germany, April 2008), PI demonstrated through a test bed assembly that this could be achieved.
The PI working groups responsible for this issue are currently integrating additional mechanisms into the specification as a compatible option. These include, in particular, Dynamic Frame Packing (DFP) and Fast Forwarding. By means of DFP, the nodes in a line structure exchange frames that become shorter and shorter on the way through the nodes. By means of ?Fast Forwarding?, a short transit time near the technical limit of Ethernet technology is achieved but without sacrificing the complete openness for standard TCP/IP available today.
The main design goal of all current activities of PI is complete compatibility with today?s device range. Existing devices can be operated in combination with devices that use the optional mechanisms mentioned. From the user perspective, therefore, nothing changes.
The working groups comprise technology suppliers as well as device and system manufacturers in order to ensure open and compatible integration into existing basic technologies and devices. The specifications will be finished in the second half of 2009.
Together with the currently available optional functions, such as accelerated startup times (?Fast Startup?) and Isochronous Mode, the modular and flexible PROFINET technology meets the requirements of all sectors and markets ? ranging from process industries to high-end machine building.
For this reason, manufacturers are relying more and more on the open PROFINET standard, with the added certainty that participation in further innovation development activities is possible.