Why We Built a PLC Simulator — and Who It's For

Since this site launched, the editorial team has published tutorials on ladder logic, function blocks, structured text, and vendor-specific workflows for Siemens, Allen-Bradley, Mitsubishi, Omron, and CODESYS.

Reader feedback kept returning to the same question:

"Great article. Now — where can I actually try this?"

The honest answer was uncomfortable. Every established option solved a different part of the problem:

• Vendor engineering simulators provide the closest match to a supported controller family, but require the corresponding engineering workflow, compatible platform, and licence.
• Plant simulators provide useful machine and process interaction, but normally need a PLC, soft controller, or separate logic environment to drive them.
• Open-source runtimes provide flexibility and inspectable code, but leave more installation, configuration, and exercise design to the learner.
• Browser logic editors make experimentation easy, but many do not provide a structured curriculum, repeatable plant states, or scored test cases.
• Legacy classroom products can teach useful fundamentals, but may not reflect current workflows, operating systems, or controller families.

That left a practical access gap for readers using a Mac, Chromebook, Linux laptop, or a computer on which they could not install an industrial engineering suite. The obstacle was not a shortage of documentation; it was getting enough deliberate, testable programming practice.

What we built

plcsimulationsoftware.com is a browser-based PLC learning and practice simulator. That's the one-sentence version. The longer version:

• Versioned practice catalogue. The current curriculum, scenario-catalogue label, access rules, and rollout limitation are published in the product's machine-readable facts record.
• Documented learning dialects. The maintained dialect list is published in that same facts record so this article does not preserve a stale count.
• No local engineering-suite install. The learning environment runs in a browser; production work still belongs in the target vendor environment.
• Cross-platform access. A modern browser makes the practice environment available on common desktop and education-device platforms, subject to the product's current browser support.
• Free account available. The current allowance and account conditions are documented in the facts record; availability of individual lessons and scenarios can vary by plan, entitlement, and staged rollout.

The product's most important learning mechanism is the auto-grader. Watching your code run is good. Watching it fail a specific test case — "the motor did not stop within 500 ms of the E-stop signal" — and then fixing it is how you actually learn. That is what the scenarios do. They do not just animate; they evaluate.

Who it's for

If you read this blog, there's a decent chance it's for you. But specifically:

Self-taught learners. You don't have a Siemens or Rockwell employer handing you a licence. You need something you can open on a Tuesday evening and get reps in. The simulator's free tier was designed for exactly this — no credit card, no install, and enough scenarios to get you to "oh, I get it" on the scan cycle.

Students on Chromebooks. Reader feedback frequently comes from high-school robotics students and community-college mechatronics students whose school-issued devices cannot install anything. ChromeOS support was therefore an early product requirement. Detailed Chromebook page here.

Mac and Linux users. If you've ever fought Parallels or Wine to get TIA Portal running, you already know why this exists. The simulator runs natively in Safari, Chrome, Edge, and Firefox. Mac-specific page. Linux-specific page.

Career-changers. Software engineers coming into OT. Electricians going from relay logic to ladder. Maintenance techs moving up to controls. The career transitions covered on this site benefit from graded practice before work begins on real hardware.

Interview prep. Timed, testable exercises can expose gaps in sequence design, interlocks, timers, and fault handling before a technical interview. They should be treated as practice—not as a claim that every employer uses the same interview format.

Who it's not for

The boundaries matter just as much as the capabilities.

• It is not a replacement for PLCSIM, Logix Emulate, or TwinCAT for production work. If you need bit-identical fidelity against a specific S7-1500 deployment, use PLCSIM. If you are virtually commissioning a ControlLogix line, use Logix Emulate. If you are building a TwinCAT machine, you need TwinCAT. The product site publishes comparison pages for each: PLCSIM, Logix Emulate, CODESYS, Factory IO.
• It is not a Mitsubishi or Omron emulator. The learning dialects teach transferable conventions, but do not emulate every Mitsubishi FX/Q address or Omron CJ/CP memory behavior. The IEC concepts transfer; production-specific addressing and firmware behavior still require the vendor environment and target hardware.
• It's not a real PLC. You cannot ship a project to a Rockwell PLC from here. The simulator builds fluency; the vendor IDE ships code. Different jobs, different tools.

What this changes on plcprogramming.io

Not much, honestly. The tutorials, brand guides, career pages, and practical PLC programming examples stay.

What changes is that where a tutorial says "now practise this," the site can finally point somewhere real. High-traffic tutorials now include a practice box linking to an intent-matched simulator surface. That article-to-practice bridge is the purpose of operating the two sites together.

What we want from readers

If a tutorial is missing an obvious "now do it" path, use the site's correction channel to tell us. The same learner moves between both sites, and reader feedback is the best evidence of whether that bridge feels useful or intrusive.

And if you've been looking for somewhere to actually get reps in between tutorial readings — it's here, it's free to start, and it runs in your browser right now.

That was always the idea.