Like any computer based system, your control system is loaded with capabilities that may go unused or under-utilized. How many of you have used every feature that Microsoft has packaged into the operating system on your computer? (Some of you, like me, use an Apple machine, but the point is still valid). You might think that you are wasting money by not using every bit of what you have.
I have learned lots of tricks over the years to make use of lesser known features of control systems. When I worked for Honeywell I delivered “Slick Tricks” presentations to show users clever ways to provide functionality in the control system using hidden features. These hidden gems can yield results without the investment in additional hardware or software. The engineer who figures out how to make the most out of the existing control system can acquire hero status.
There are caveats to this approach. The hidden gems might be hidden because the control system vendor doesn’t want you to risk performance or reliability. Being hidden, they are likely to be secrets to all other engineers. When the engineer who designed the secret solution is no longer around, will you have anyone else that can maintain the system? Will you now be dependent upon a piece of software that can’t be fixed if it breaks?
The motivation to find clever techniques amplifies the larger a system grows. When you start to run short on IO, processing, or other limited capacities, it is appealing to squeeze the most of out your control system to put off the need to purchase more hardware or software.
This is sometimes when I get called to the rescue and figure out how to fix things in a control system. I might be the only one you can find that can uncover the design of complex approaches that involve a control system’s hidden features.
I once was called to a site that makes some very toxic chemicals. They needed me to make online configuration changes (without interrupting production or causing a dangerous accident). They had a system that had logic scattered throughout the PLC and HMI software that made it difficult to figure out where the control signals were coming from and the logic behind it. It was clear to me that a prior engineer was more driven by the capital budget than by long-term cost, maintenance, safety, and reliability of the system. Through careful steps I was able to complete the necessary changes, but left that site with a heightened awareness of these concerns.
Your control system is a critical component of your operation. There are times when an expert can save you money and provide great benefits through clever techniques. There are also times when the proliferation of these practices produce a Frankenstein system, which can cause monstrous problems for your operation. Spending the money to configure your system the simple way can save you money in the long run.