Frequently asked questions
The most common questions about the project, the simulator and how to learn.
About the project
Is PLCampus free?
Yes. All the content, the simulator, the examples and the challenges are free and you do not need an account.
The project is kept alive by voluntary donations. There are no ads in the simulator or the challenges.
Where are my programs and progress stored?
Only in your browser (local storage). We do not send them to any server.
If you clear your browser data or switch computers, they are lost. To keep a program, download it with File → Download project; you can then open it on any computer.
Are you affiliated with any PLC brand?
No. This is an independent educational site. We mention brands only to explain how each one works; their names belong to their owners.
I found a mistake. How do I report it?
Open an issue in the project’s GitHub repository, linked at the bottom of every page. Tell us the page, what you expected and what happened.
About the simulator
Why does the simulator not work on my phone?
The simulator is a CAD-like editor with panels, drag and drop and keyboard shortcuts: it needs a screen at least 1024 px wide. The theory, example and challenge pages can be read on a phone.
Can I download the program to a real PLC?
Not directly. The simulator is a learning tool: each brand uses its own software and file format.
What you learn does carry over: contacts, coils, timers and counters work the same on any PLC that follows IEC 61131-3.
Which programming languages does the simulator support?
Today, Ladder (LD). Structured text (ST), function block diagram (FBD), instruction list (IL) and SFC will come in future versions; all of them will run on the same engine.
Does the simulator behave like a real PLC?
It imitates the essentials: scan cycle, process image, IEC 61131-3 timers and counters, forcing and watchdog. Time is simulated, with a fixed 10 ms cycle.
Each brand has its own details (cycle times, special instructions, error handling) that we do not reproduce. For a real project, always check the device manual.
Can I see addresses as in Siemens, Allen-Bradley or another brand?
Yes. In the simulator toolbar, the “Addresses” selector shows the same program in Siemens, Allen-Bradley, Mitsubishi or Omron notation. It is only a view: the program does not change.
About learning PLCs
I have never seen a PLC. Where do I start?
Read the “Learn” topics in order, starting with “What is a PLC?”. Then open the lamp example in the simulator and move on to the challenges: they are ordered by difficulty.
Do I need to know electricity?
To program in the simulator, no: basic logic is enough. To work with real PLCs, you do need electrical and electrical-safety knowledge; work on panels must be done by qualified personnel.
Which PLC brand should I learn?
Whichever is most used in your area or in the industry where you want to work. The concepts are the same in all of them, so what you learn here will help with any brand.
In the “Brands and software” section we compare the main ones and which have free software to practise with.
Do you give certificates?
Not for now. The goal is for you to learn and practise for free.
Did not find your answer? Write to us by opening an issue on GitHub.