Who stole my PLC?

Brown, Jeff

The second group will pack up and head out into the maze with their maps, while the first group will still be wondering, “Who stole my PLC?” There will be hope for the first automation group if they can muster up the courage to enter the maze.

I have a certain knack for observing human behavior that I believe extends from having lived in 16 different homes before age 1.8. After each move, I always found myself on the outside of a new social order looking in as an observer. I have carried this knack over to my current role in the automation control industry. Observations of automation users have led me to the following insight: I believe there are quite a few similarities between the story Who Stole My Cheese and automation users’ programmable logic controller (PLC) behavior. I call this Who Stole My PLC.

In the story Who Stole My Cheese, two humans and two mice find a humongous pile of cheese in a maze. The mice would leave the pile of cheese and explore the frightfully scary maze every day, because they knew the pile of cheese would not last forever. In contrast, the two humans believe the pile of cheese will never go away. One day the pile of cheese was all gone, and the humans never saw it coming. The mice, on the other hand, saw it coming all the time. The mice were not afraid to venture out into the maze, and they found a new pile of cheese. The humans, however, sat in denial that their cheese was gone, and they absolutely did not want to explore the dreadfully scary maze.

One of the humans finally overcame his fears and ventured out into the maze. After much trial and error, he found the mice and their new pile of cheese. He promised to always make sure he explored the maze so he was ready when the pile of cheese was no longer there. The other human continued to sit with no cheese, waiting for his cheese to return and asking” Who stole my cheese?”

Ageless PLCs

Now instead of cheese and mice let’s suppose we have humongous piles of PLCs and two groups of automation users. The first group is very content with the PLCs they get from their large supplier. They have a very nice supplier partnership, and they can get all the PLCs they could ever need right when they want them. The first group believes they have an endless supply of technicians and engineers who know PLCs.They believe their supply of PLCs will never run out-so why should they venture out into the scary maze to look at new technologies? It is scary out there with lots of risk. Sourcing different products would be very difficult. Replacing PLCs with something like PCs means they would have to consider new problems such as viruses and getting other people such as IT involved. That is a lot of work when you have an endless supply of PLCs from a great partner.

The second group of automation people is not comfortable with their humongous piles of PLCs. They realize the cost of PLCs from their comfortable source is rising and the technology seems a little outdated and closed. They realize that getting data in and out of PLCs can be difficult. They realize their most knowledgeable PLC people are nearing retirement age. They are seeing new technicians and engineers who learned to use a mouse before they could write. They also realize their humongous pile of PLCs is getting expensive. They realize eventually they will have to venture further into the maze than they have ever been. They prepare for that day just like the mice did in Who Stole My Cheese by exploring the maze.

New vision

What do they see when they explore the maze that will ultimately become their map? They see automation suppliers with technologies that look like PLCs but are really open controllers based on standard PC technology. They see automation suppliers who have successfully been doing PC-based motion and sequencing control since 1989 on x86 PCs with a DOS operating system. They see open fieldbus systems based on Ethernet and the ability to connect several suppliers’ drives, I/O, and human-machine interfaces together. They see standard programming languages such as IEC 61131-3, which allows them to easily migrate one pile of hardware to another pile. They see as much as 50% hardware cost reductions. They realize that some day their pile of PLCs might not sustain their production requirements.

When that day comes the second group will pack up and head out into the maze with their maps, while the first group will still be wondering, “Who stole my PLC?” There will be hope for the first automation group if they can muster up the courage to enter the maze.

Behind the byline

Jeff Brown is the north central sales and marketing manager for Beckhoff Automation. His e-mail is j.brown@beckhoff.com.

Face to face with project management

Case history: Drug storage, refrigeration