CIP Safety: Fail-safe communication between nodes

CIP Safety, for functional safety applications on the EtherNet/IP and DeviceNet networks, provides fail-safe communication between nodes, such as safety I/O blocks, safety interlock switches, safety light curtains, and safety PLCs in safety applications up to Safety Integrity Level (SIL) 3.


Diagram shows how safety data is routed between DeviceNet and EtherNet/IP in CIP Safety applications. Courtesy: ODVACIP Safety, the extension to the Common Industrial Protocol (CIP) for functional safety applications on the EtherNet/IP and DeviceNet networks, provides fail-safe communication between nodes, such as safety I/O blocks, safety interlock switches, safety light curtains and safety PLCs in safety applications up to Safety Integrity Level (SIL) 3, pursuant to IEC 61508 standards and as certified by TÜV Rheinland. CIP Safety devices have been working in the field since 2005, and according to the 2011 World Market for Industry Networking study by IMS Research, CIP Safety is now the largest safety networking protocol, accounting for 30% of all new safety nodes installed. In addition to its use in EtherNet/IP and DeviceNet installations, CIP Safety has been adopted by SERCOS International as the only safety protocol for use on SERCOS III networks. 

Safety application coverage in CIP provides the ability to mix safety devices and standard devices on the same network or wire for seamless integration and increased flexibility. Because the safety application layer extensions do not rely on the integrity of the underlying standard CIP services and data link layers, single channel (nonredundant) hardware can be used for the data link communication interface. This same partitioning of functionality allows standard routers to be used to route safety data. The routing of safety messages is possible, because the end device is responsible for ensuring the integrity of the data. If an error occurs in the transmission of data or in the intermediate router, the end device will detect the failure and take an appropriate action.

This routing capability allows the creation of CIP Safety cells with quick reaction times on one network, such as DeviceNet, to be interconnected with other cells via other networks, such as EtherNet/IP. Only the safety data that is needed is routed to the required cell, which reduces the individual bandwidth requirements. The combination of fast-responding local safety cells and the inter-cell routing of safety data allows users to creates significant safety applications with fast response times. 

Users of CIP Safety on EtherNet/IP benefit from not only the proven benefits of CIP Safety itself, but also the benefits of the CIP and EtherNet/IP. CIP encompasses a comprehensive suite of messages and services for the collection of industrial automation applications—control, safety, energy, synchronization and motion, information and network management—and allows users to integrate these applications with enterprise-level Ethernet networks and the Internet. EtherNet/IP—the adaptation of CIP on standard Ethernet technology (IEEE 802.3 combined with the TCP/IP Suite)—provides users with the network tools to deploy industrial automation applications while enabling Internet and enterprise connectivity, resulting in data anytime and anywhere.

With the application of networked motion growing as an area critical for safety technology, ODVA, the organization that manages the CIP Safety technology, is investigating the expansion of the application coverage of CIP Safety to include safe motion. Using the safety functions defined in IEC 61800-5-2 (Adjustable Speed Electrical Power Drive System – Part 5-2: Safety Requirements – Functional) as a framework, ODVA will be defining the requirements for use of safe motion in systems deploying CIP Safety by considering target use cases and control architectures for safe motion applications; safe motion functions that need to be supported, such as safe torque off and safety limited positions; the required data model; and mapping of a safe motion data model to objects and services needed in CIP Safety to support a safe motion profile. ODVA will also be looking to SERCOS International, which has standardized on CIP Safety and is a recognized leader in the application of networking to motion control applications, for input.

- Katherine Voss is ODVA executive director; edited by Mark T. Hoske, content manager CFE Media, Control Engineering and Plant Engineering,



Integrated Safety Helps Control System Design



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
A cool solution: Collaboration, chemistry leads to foundry coat product development; See the 2015 Product of the Year Finalists
Raising the standard: What's new with NFPA 70E; A global view of manufacturing; Maintenance data; Fit bearings properly
Sister act: Building on their father's legacy, a new generation moves Bales Metal Surface Solutions forward; Meet the 2015 Engineering Leaders Under 40
Cyber security cost-efficient for industrial control systems; Extracting full value from operational data; Managing cyber security risks
Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again
Pipeline vulnerabilities? Securing hydrocarbon transit; Predictive analytics hit the mainstream; Dirty pipelines decrease flow, production—pig your line; Ensuring pipeline physical and cyber security
Upgrading secondary control systems; Keeping enclosures conditioned; Diagnostics increase equipment uptime; Mechatronics simplifies machine design
Designing positive-energy buildings; Ensuring power quality; Complying with NFPA 110; Minimizing arc flash hazards
Building high availability into industrial computers; Of key metrics and myth busting; The truth about five common VFD myths

Annual Salary Survey

After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.

The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.

Read more: 2014 Salary Survey: Confidence rises amid the challenges

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.