Who's changing settings on your instrumentation?

Let's say a pressure sensor regularly bumps against its alarm limit. An operator decides to take a hand-held and shift it just a little to knock off the racket. Is that OK?


Recently I heard a report that a well known oil, gas, and petrochem industry company had done a survey of the instrumentation in one of its plants. The company was dismayed to find that many of the devices had settings that were different than they were supposed to be according to the database in the control system.

Further investigation determined that it was a relatively common practice for operators to go into the plant with a hand-held interface and tweak settings. Several reasons were cited for this, but the most common had to do with trying to reduce the number of "nuisance" alarms. In most cases the changes were appropriate or at least tolerable and did not result in unsafe conditions. However making such adjustments without updating the database information is not a good idea for any number of reasons.

The problematic practice was limited to the parts of the plant that operated with hard-wired analog communication. Most devices involved were HART enabled and it was very simple to change the configuration in the field with a hand-held communicator. Operators did update the database from time to time, but this was the exception.

Other parts of the plant operate using fieldbus communication, which makes this type of unmanaged change much more difficult. Platforms such as Foundation Fieldbus and Profibus PA allow for such setting changes, however the procedure involves doing it from a more centralized location such as an engineering station. Modifications require appropriate clearance, are recorded by the system, and can be set to update the database automatically.

Without such built-in procedures, change management becomes a matter of training and discipline among operators. If it is not followed and the information in the control system no longer reflects reality, it isn't difficult to imagine the kinds of problems that could result during troubleshooting or in the wake of an upset or accident.

What is your experience? Does this sort of thing go on in your plant? Is it a problem?

Join the discussion and offer your thoughts on this topic, which is now featured in the "discussion" areas on the Control Engineering groups at Facebook or Linkedin .


-Peter Welander, process industries editor, PWelander@cfemedia.com,
Control Engineering Process Instrumentation & Sensors Monthly
Register here to select your choice of free eNewsletters .


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.