Safety instrumented systems: Tips from the trenches: Part I

Jul 30, 2015 9:25:25 AM | Posted by Jay Griffin

The two-part installment introduces safety instrumented systems (SIS) and outlines specific tips on designing, developing, and verifying SIS applications.

Today’s article focuses on the purpose and application of the SIS as well as safety integrity layer (SIL) calculations. The second installment will finish up with exploring tips for SIS hardwarde and the control system interface. 

Read More →

Legacy Software Blues

Jul 21, 2015 3:57:00 PM | Posted by Tim Gentry

Is Your Customer’s Legacy Software Platform Holding Them Back? Virtualization Can Offer Them a Safe and Affordable Path Forward.

When integrators do a really good job, sometimes we give our clients a false sense of permanence. The rock solid system you set them up with performs flawlessly. So well, in fact, that they never have to think about it, much less considered upgrading. Why would they when their current system works, operators are familiar with it and, most importantly, it’s paid for?   

Read More →

Timekeeping protocols for control systems: What time is it?

Jul 9, 2015 10:20:57 AM | Posted by Robert Henderson

Do we care what time it is?

Do you have a control system that only uses buttons and lights to interact with operators?  Is it missing real-time trending, alarm historian and regulatory reporting?  There are certainly control systems that don't have a need for accurate clocks, but they are few and far between.  Let us assume you do not have one of those systems and keeping time is vital to your operations.

It is always good to have accurate time, but it is more important to have synchronized time.  If every clock in the building is 10 minutes slow, then you can still tell which of two events happened first. You're going to have a big problem on your hands if your DCS has one time, your database server has another, a PLC has a third, and they all drift independently. Sequence of Events (SOE) operations, time stamped I/O and alarming, and synchronized motion are all applications that mandate synchronized clocks.

Read More →

Do I really need this alarm?

Jun 30, 2015 4:55:59 PM | Posted by Mike Robb

A common occurrence is an alarm being driven by code that is no longer being utilized. A periodic review of alarm philosophy should be conducted by third-party or plant maintenance employees.

Have you ever reviewed the list of standing alarms in your plant?  Do you see alarms that always seem to be cycling?  Are there multiple alarms that have indicated an alarm state for an extended period of time? Have operators silenced or disabled the alarms that are constantly going off? I have found numerous power plants that have forced off or silenced alarms due to the repeated activation just so they can put more focus on the 300 other active alarms during normal plant operations.  A review of the standing alarms often leaves you wondering which alarms the operator notices when overwhelmed with so many. So how do you make sure you have the right alarms in place?

Read More →

How Information Provides Insights and Changes Behaviors

Jun 25, 2015 12:43:00 PM | Posted by John Boyd

The challenge of gathering historical and real-time data is to provide that data back to the user in a way that provides insights. This can be accomplished by providing thought-out dashboards and reports to key operational personnel and managers.

We tend to put a lot of effort into gathering historical and real-time data in the industrial process environment. The challenge is to provide that data back to the user in a way that provides useful performance data. This can be accomplished by providing thoroughly thought-out dashboards and reports to key operational personnel and managers. It is amazing what behaviors that can be changed in a processing environment if everyone is given the right information.

Read More →

To alarm or not to alarm?

Jun 17, 2015 2:21:00 AM | Posted by Jeff Wood

Alarm rationalization is a step that should be taken to avoid the generation of unnecessary alarms. Otherwise the alarm may end up of the alarm list and stay there for a while.

To alarm or not to alarm? That is the question. There are many control room alarm screens with alarms that are hours, days, and sometimes weeks old. Why did these alarms show up on the screens if they were not important enough to address at the time they occurred? Was the operator in a hurry to acknowledge the alarm to stop the horn? Are there so many alarms that come in that the operator is overwhelmed by the number of alarms that come in. Are there multiple alarms for the same signal or occurrence? Is the alarm just not that important?

Read More →

User-defined function best practices

Jun 10, 2015 5:20:00 AM | Posted by Jeff Monforton

When designing the UDF, there are some questions that need to be considered.

Modern automation controllers continue to expand with options and opportunities for the programmer. One of those improvements is the ability to develop User-Defined Functions (UDF), or Add-On Instructions in the Rockwell Automation ecosystem. These improve portability, consistency, and code security, all of which add to the kit of the automation programmer. Like all tools they can be used properly or abused; who hasn’t pried the lid off of a can of paint with a ‘screwdriver’? I’d like to take a moment and discuss some of the options and opportunities that these constructs offer and some of the Best Practices that should be employed.

Read More →

Do your progress meetings hinder progress?

Jun 2, 2015 9:32:00 AM | Posted by Fcedotal

Learn how to keep track of the massive programming efforts by using agile software development techniques.

Have you been asked to report your progress in percent complete, while what you really want to say is “Leave me alone, I’ll be ready for startup.” There is an axiom in software development that says: 80% of the code takes 20% of the time and 20% of the code takes 80% of the time. Part of the reason is that the bulk of coding is things that are clear and you know how to do, so you speed through it. But the parts that you don’t know how to do take much longer to figure out. So, how do you really know where you are when you get finished with the parts that you know how to do?

Read More →