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Developments in real‐time control with EtherNet/IP

R.S.H. Piggin (Rockwell Automation, Milton Keynes, UK)

Assembly Automation

ISSN: 0144-5154

Article publication date: 24 April 2007




Ethernet continues to evolve as a viable fieldbus technology for industrial automation. This paper seeks to discuss the development of the Common Industrial Protocol (CIP) for Ethernet and standards with particular reference to time synchronisation, real time motion control and safety.


The CIP is introduced, with an overview of four network adaptations: CompoNet, DeviceNet, ControlNet, and EtherNet/IP. Developments in the EtherNet/IP implementation are discussed, along with key features. These include CIP Safety to meet the requirements for safety‐related control, CIP Sync for time synchronisation across CIP networks and CIP motion for real‐time closed loop motion control.


Standard, unmodified Ethernet will support time synchronisation, real time motion control and safety‐related applications with the CIP adaptation EtherNet/IP. The CIP enables complete integration of control with information, multiple CIP networks and internet technologies. CIP provides seamless communication from the plant floor throughout the enterprise, with a scalable and coherent architecture, incorporating functionality, such as safety, time synchronisation and motion control, hitherto only available with specialised or incompatible networks.

Practical implications

The implementations of CIP Sync, CIP Motion and CIP Safety and the corresponding standards provide functionality and flexibility not available from disparate specialist networks. The ability to fully integrate internet technologies and safety, synchronisation, motion and safety together is a distinguishing feature. Industrial Ethernet technologies vary in the ability to integrate to the same level of functionality and offer similar flexibility.


The development of CIP technology and the use of open standards are described. The opportunity to use the combination of an established automation protocol and standard, unmodified Ethernet provides potential cost benefits, flexibility, and innovative solutions, whilst providing integration, performance and cost advantages.



Piggin, R.S.H. (2007), "Developments in real‐time control with EtherNet/IP", Assembly Automation, Vol. 27 No. 2, pp. 109-117.



Emerald Group Publishing Limited

Copyright © 2007, Emerald Group Publishing Limited

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