Standardized sensor profiles improve safety-related process data

Controller Area Network (CAN) in Automation (CiA) recently released CAN device profiles that aim to standardize safety-related process data.


Figure 1: A typical CANopen Safety rotational encoder is used in electrical drive applications and mobile machines where the rotation needs to be measured. Courtesy: TWKThe standardized sensor profiles include encoders and inclinometers, which have been updated and released as version 4.0 and 2.0 respectively. Both profiles specify safety-related sensor data and its mapping into safety-related data objects (SRDOs) as defined in CANopen-Safety (EN 50325-5). These specifications are the first ones standardizing functional safety on a device's profile level.

CANopen-Safety is supported by an increasing number of IEC 61131-3 programmable controllers. Up until now, they have mainly been applied to mobile machines. The released CANopen sensor profiles allow interoperability between encoders and inclinometers from different vendors. "The success story of the CANopen device profiles continues also for functional safety," said Holger Zeltwanger, CiA's managing director. "The standardized device profiles simplify system integration, and the machine builder can substitute a product more easily."

Encoders and inclinometers

Figure 2: Linear encoders are often implemented in conjunction with hydraulic actuators. Courtesy: TWKEncoders and inclinometers are used in many machines to measure the angle, the revolution, and the length. Encoders can also be used to measure the speed, which is length divided by time, the acceleration, and the deceleration-or the jerk. The related CANopen device profiles specify the process data to be mapped in normal PDOs.

The inclinometer profile also standardizes the safety-related configuration data. This includes the preset values for the lateral and the longitudinal direction as well as the safety application configuration valid parameter, which is set to valid after the configuration is completed and the configuration signature has been generated correctly. The safety application configuration signature contains standardized checks that protect the safety configuration against unintended changes. This function is double-checked periodically by the safety-related application program. In addition, the standardized safety profiles enable the system designer to exchange products without changing the safety-related application software.

Figure 3: Rotational encoder supporting CANopen Safety and CiA 406 version 4.0 feature interoperability and interchangeability, which is made for safety-related communication. Courtesy: TWKMost of the applications in mobile machines require a Safety Integrity Level (SIL) of two, according to the IEC 61508 standard. The CANopen Safety protocol is suitable for SIL-3, and can also be used for lower levels. CiA has implemented the CANopen Safety protocol in a single micro-controller with two CAN on-chip modules.

Edited by Jessica DuBois-Maahs, associate content manager, CFE Media,

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.