Improved architecture for Profinet IRT devices

This paper deals with Real-Time applications based on Profinet IO Real-Time Class 3. The industrial automation in some cases requires the precision of IO data timing well below the delivered cycle time on the bus. When using the Isochronous Real-Time protocol of Profinet, one single predefined time within a cycle time can be chosen for the inputs- and outputs. The work presented here, shows how the architecture of a Profinet device can be improved. The user can define the time of an input or output within the given time slot with an accuracy of 65 nanoseconds. Furthermore the feasibility of the proposed design is proven with several measurements and simulations.