Today in an automated world, programmable logic controllers (PLCs) are the backbone of nearly every productive industrial operation. Every industrial process, from assembly lines and material handling, to quality testing and energy controls suffer without PLCs. PLCs are reliable industrial computers that take snapshots of inputs and outputs and respond to those in a set fashion—by following a predetermined program (written by a professional, termed a PLC programmer).
If you're interested in a career that utilizes industrial automation, or want to transition into an emergent field, learning PLC programming is the right move. This article intends to describe what defined PLC programming is, how it works, and what is required to learn the skills to start programming PLCs.
What Is PLC Programming and Why It’s Important
A PLC is hardware on its own. Its power comes when the PLC is programmed to complete specific tasks whether it’s turning on a motor, counting product units, or reacting to, in milliseconds, a signal from a sensor.
Well-written PLC programs are important for:
- Reliable automation of repetitive tasks
- Human error and less downtime
- Improved product consistency and quality
- Real-time monitoring of industrial processes
- The ability to scale or upgrade systems over time
How PLC Programming Works
Programmers utilize software tools specific to each PLC brand (like Omron's CX-Programmer and Allen-Bradley's Studio 5000) to write logic that's uploaded into a PLC's memory. The PLC starts executing the logic in an endless loop from the moment it receives power, structured in a loop (known as a scan cycle) that monitors inputs and makes decisions to output appropriate signals.
Real-World Example: Conveyor Control
Input: A photo sensor detects that a box has arrived on the belt.
Logic: If a box is on the belt and the next station is clear, start the motor.
Output: The motor immediately starts and moves the belt forward.
Scan again: The PLC scans again and the outputs can change again if necessary.
PLC Programming Languages You'll Use
Most PLC's utilize the IEC 61131-3 programming stipulated standard. The three most common programming languages are:
Ladder Diagram (LD)
Graphical format similar to electrical schematics
Great for technicians that are electricians
Function Block Diagram (FBD)
Visual block with 'flow of data'
Commonly used for process control and analog operations
Structured Text (ST)
High-level text logic, similar to Python or C
More powerful logic for math, looping, or complex conditions
What Does Every PLC Programmer Need to Know?
You may not need to become a software engineer—but you need the right mindset and a baseline of knowledge. Many successful PLC programmers have:
Excellent problem-solving skills
Basic knowledge of electricity
Attention to detail
Familiarity with machinery
Good communication skills to work with non-software, non-technical stakeholders
How to Begin Learning to Program PLCs
1. Learn the Fundamentals.
Start with free and/or paid courses on learning IEC 61131-3 languages, logic operations, timers, counters and scan cycles.
2. Hands-On Learning.
Help on real projects: debug code, edit minor programs, or follow around an experienced technician.
3. Create Real Systems.
Create simulations with simulation software (such as Factory I/O or PLCLogix) or real hardware for practice.
The more common pathways are from electrical people, maintenance, automation support roles, or machine setup positions moving into PLC programming over time.
Where to Go From Here: Learn About TopAutoDevice PLC Products
If you are learning PLC programming or currently working within an automation role, having the appropriate PLC hardware, instrumentation and tools for your projects is very important.
At TopAutoDevice, we offer a large selection of industrial-quality PLCs for automation and industrial purposes from globally trusted brands like: Omron, Siemens, Schneider Electric, Allen-Bradley, Mitsubishi and more.
Regardless if you are implementing your first PLC or upgrading new systems in a production facility, we have the solutions and experience to assist you.
Check Out PLC Products for the right model
In conclusion
PLC programming is not just about writing code, it is about controlling machines, resolving real world challenges and keeping industries on track. From conveyors to robotic arms and inspection systems, learning PLC programming will ensure you have a future facing and relevant skill set.
Are you ready to get started? Get the right tools.
Reach out to our experts in automation solutions or take a look at our range of PLC systems on TopAutoDevice.
