Industrial controls are behind countless automated systems but understanding how all the pieces work together is very different from learning about them in a classroom.
Since joining OSCO Controls as a Controls Engineer, I’ve had the opportunity to work directly with industrial control panels, PLC programming, HMIs, sensors, VFDs, safety devices, and custom automation systems. Even in my first few months, one thing has become clear: controls engineering is about much more than making equipment move.
It’s about figuring out how to make an automated system safer, smarter, more precise, easier to operate, and better suited to the application.
Here are some of the biggest lessons I’ve learned so far.
Industrial Controls Can Make a Good Automation System Better
Before hearing about OSCO Controls, I wasn’t exactly sure what a controls engineer did.
I had learned about controlling systems during college, but I thought of controls primarily as something engineers applied within other engineering jobs—not necessarily as an industry and engineering discipline of its own.
One of my biggest surprises since becoming a Controls Engineer has been seeing just how many different types of automation can benefit from industrial controls.
Now, I find myself looking at systems in everyday life and wondering: How could controls make this better?
That question gets to the heart of what I’ve learned about industrial automation.
Controls can take a good mechanical system and make it better by adding safety, functionality, precision, and usability. This becomes especially important when the equipment or automation system is large or complex.
PLCs, HMIs, Sensors and VFDs Each Have a Different Job
One of the first things you learn when working with industrial control systems is how many components have to communicate and work together.
Some of the components I work with most frequently include PLCs, HMIs, sensors, and variable frequency drives (VFDs).
The PLC Is the Brain of the Control System
The programmable logic controller, or PLC, is essentially the brain of the control panel.
It receives inputs from throughout the system, analyzes that information according to its programming, and determines what outputs need to be sent to the equipment.
The PLC is where much of the system’s decision-making happens.
Sensors Tell the PLC What’s Happening
For a PLC to make those decisions, it needs information.
That’s where industrial sensors come in.
Depending on the application, sensors can provide information about variables such as:
- Position
- Temperature
- Pressure
- Movement
Those inputs allow the control system to understand what is happening with the equipment and determine what should happen next.
HMIs Connect the Operator to the Machine
A human-machine interface, or HMI, helps operators interact with and understand the automation system.
An HMI may be used to operate equipment, but it can also work with the PLC to visualize what’s happening throughout the system.
That becomes particularly useful for industrial troubleshooting and diagnostics. Instead of simply knowing that something isn’t working, an HMI can help operators identify and display problems so they can more easily determine what needs attention.
VFDs Provide Precise Motor Control
Variable frequency drives, or VFDs, aren’t necessary in every control panel, but they’re common in many of the systems we design.
VFDs allow us to precisely control motors. That precision can improve equipment operation while also helping reduce energy consumption and mechanical wear.
The important lesson for me has been that these components aren’t simply a collection of parts inside a panel. They have to function as one complete industrial control system.
The Hard Part Isn’t Knowing What Should Happen—It’s Programming Every Possibility
From the outside, an industrial control panel can look fairly straightforward.
The complexity becomes much more apparent when you start programming the control logic.
It’s relatively easy to sit down and say, “When this happens, I want the machine to do this.” You can identify the inputs and outputs and understand the desired result.
Actually creating the PLC logic to make that happen reliably is another matter.
You have to think through everything that could happen within the system—not simply what should happen during normal operation.
Programming needs to account for efficiency, equipment longevity, operating conditions, and, most importantly, worker safety.
That’s challenging, but it’s also one of my favorite parts of controls engineering.
I enjoy solving problems and making things better. There is a method behind everything that goes into these programs, so you can brainstorm how the system should behave, work through the problem, and eventually arrive at a solution.
Custom Controls Engineering Starts With the Application, Not the Components
One of my favorite things about working at OSCO Controls is that we primarily work on custom industrial control systems.
That means we’re regularly presented with interesting applications and requests from customers across different industries.
Instead of mass-producing one standard control system, we have the opportunity to tailor each project around what the customer and application actually need.
That has taught me that good controls engineering isn’t about simply selecting the cheapest or most convenient components.
There’s a lot of engineering and math involved in making sure each component is appropriate for the application and compatible with the rest of the system.
The goal is to make sure the entire automation system works together.
Mechanical Equipment, Electrical Controls and PLC Programming Have to Work Together
Another lesson I’ve learned is how closely mechanical equipment, electrical controls, and programming are connected.
I think of mechanical equipment as the skeleton of the automation system. In material handling applications, that may include a lift, its actuators, gates, and other moving components. OSCO Controls designs and builds the industrial control panels that help control how those components operate and work together.
The electrical controls allow us to understand what’s happening with that equipment. Sensors can detect variables such as temperature, position, pressure, or movement and relay that information to the PLC.
The PLC then uses its programming to decide what the mechanical equipment should do based on those inputs.
You can’t really look at the mechanical, electrical, and programming portions independently. A successful automated system depends on all three working together.
Safety Has to Be Designed Into the Control System
One of the most important things I’ve learned is that industrial controls engineering is closely connected to machine and operator safety.
At OSCO Controls, our products are UL 508A certified, which means there are specific requirements and guidelines we follow when designing and building industrial control panels.
UL 508A requirements help address the safety of the industrial control panel itself, including reducing electrical and fire hazards that could occur if something malfunctions.
But control system safety goes beyond the panel.
During design and programming, we’re constantly considering how the automation system can help protect employees including what should happen if part of the system fails.
Depending on the application, that can include features such as:
- Accessible emergency stop (E-Stop) buttons
- Requirements for gates to be closed before equipment can operate
- Limit switches that verify equipment position before another action is allowed
- Safety sensors that detect whether an area is clear before equipment such as a lift operates
- HMI screens that make system conditions, faults, and warnings easier for operators to identify
Controls gives us the ability to define not only what a machine should do, but also what conditions must be satisfied before the machine is allowed to do it.
That distinction is incredibly important.
A Key Controls Engineering Question: How Should the System Do What It’s Supposed to Do?
One question I’ve come to appreciate is:
“How do we want the system to do what it’s supposed to do?”
With custom controls engineering, there can be multiple ways to create an electrical schematic or program a PLC to accomplish a particular task.
So finding a solution that works isn’t necessarily enough.
We want our controls designs and PLC programs to be straightforward, methodical, and easy to understand.
That becomes especially important later.
If we need to return to a system and make a modification, clear programming makes it much easier to identify where a change should be made instead of trying to decipher unnecessarily complicated logic.
In other words, we’re not only thinking about whether the system works today. We’re thinking about how understandable and maintainable it will be in the future.
My First PLC Programming Mistake Taught Me a Lesson I Won’t Forget
Some controls engineering lessons are difficult to learn from a textbook.
I learned one of mine while working on the first PLC program I wrote.
I’d spent an entire day building the program and finally reached the point where I was ready to test it on the PLC.
I needed to send my new program to the PLC.
Logically, I thought that meant I should upload it.
I clicked upload and watched the program I’d spent the day creating disappear in front of my eyes.
I learned very quickly that, in this context, downloading sends the program to the PLC, while uploading retrieves the existing program from the PLC.
It was a small mistake, but it’s one I’m probably never going to make again.
More importantly, it’s representative of something bigger I’ve discovered since starting this job.
I took several controls classes in college, but even after only a few months of working with industrial automation and control systems, I’ve been exposed to concepts and real-world situations that I had very little experience within school.
I’ve learned a tremendous amount—and I also realize how much more there is to learn.
That’s one of the things I like most about engineering. Engineers never really stop learning.
Advice for Engineers Getting Started in Industrial Controls
If I could give one piece of advice to another engineer starting a career in industrial controls, it would be simple:
Never be afraid to ask questions.
One of my favorite things about working at OSCO Controls is having a boss and coworkers who are available to talk through problems and who actually want me to ask questions.
Controls engineering involves continuous learning. Every new application, component, program, and troubleshooting problem presents an opportunity to understand something better.
So, my advice is to research, ask questions, and keep learning.
There is always another problem to solve—and another opportunity to make a system better.
Make Your Automation System Work Better
Whether you’re developing a new automation system or looking to improve existing equipment, the right controls can make it safer, smarter, more precise, and easier to operate. OSCO Controls designs and builds custom industrial control systems around the specific needs of your equipment and application. Contact OSCO Controls to discuss your project and learn how our controls engineering team can help make your automation system better.