Evaluation of clock synchronization accuracy of coexistent Real-Time Ethernet protocols

This paper investigates Real-Time Ethernet (RTE) protocols for industrial applications and their clock synchronization performance. In fact, if different RTE protocols coexist on the same network sharing the same infrastructure, clock synchronization capabilities can be affected. This paper introduces a simulation environment to evaluate coexistence of RTE protocols. The proposed tool is described and validated by comparison with measurement data taken from real networks. Finally, simulation results are presented: the behavior of Ethernet/IP with IEEE1588-PTP, when it is transported over an isochronous PROFINET IO network, is shown and some improvements to the PTP tracking algorithms to ease coexistence are proposed.

[1]  Hermann Kopetz,et al.  A synchronization strategy for a time-triggered multicluster real-time system , 1995, Proceedings. 14th Symposium on Reliable Distributed Systems.

[2]  Kang Lee,et al.  IEEE 1588 standard for a precision clock synchronization protocol for networked measurement and control systems , 2002, 2nd ISA/IEEE Sensors for Industry Conference,.

[3]  A. Varga,et al.  THE OMNET++ DISCRETE EVENT SIMULATION SYSTEM , 2003 .

[4]  Nuno Pereira,et al.  INDEPTH: timeliness assessment of Ethernet/IP-based systems , 2004, The IEEE Computer Society's 12th Annual International Symposium on Modeling, Analysis, and Simulation of Computer and Telecommunications Systems, 2004. (MASCOTS 2004). Proceedings..

[5]  J. Jasperneite,et al.  Enhancements to the time synchronization standard IEEE-1588 for a system of cascaded bridges , 2004, IEEE International Workshop on Factory Communication Systems, 2004. Proceedings..

[6]  Kang B. Lee,et al.  Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems , 2004 .

[7]  Richard Zurawski,et al.  The Industrial Communication Technology Handbook , 2005 .

[8]  Wolfgang Granzer,et al.  A simulation framework for fault-tolerant clock synchronization in industrial automation networks , 2007, 2007 IEEE Conference on Emerging Technologies and Factory Automation (EFTA 2007).

[9]  Daniele Marioli,et al.  A Distributed Instrument for Performance Analysis of Real-Time Ethernet Networks , 2008, IEEE Transactions on Industrial Informatics.

[10]  A. Flammini,et al.  Testing coexistence of different RTE protocols in the same network , 2008, 2008 IEEE International Workshop on Factory Communication Systems.