CODESYS 4 Is Finally Here — But Was It Ready for Release?
So, CODESYS 4 is finally here.
And after spending some time actually installing it, running it on Windows/Linux, looking at the new web interface, dealing with libraries, and then putting the whole thing inside Docker...
I have mixed feelings.
Not negative.
Actually, quite the opposite.
I think CODESYS 4 is going in a very interesting direction.
But I also can't help asking one question:
Should CODESYS have waited a little longer before calling this CODESYS 4?
Let me explain.
First — what is actually different?
The biggest change isn't a new PLC programming language.
It isn't a completely new runtime.
It isn't throwing away everything that existed before.
The interesting part is the new user interface.
CODESYS 4 moves toward a web-based engineering experience.
And that changes the conversation.
For decades, the typical automation model has been:
Engineering PC → Install IDE → Install libraries → Configure environment → Connect to PLC
Now we're starting to see another model:
Browser → Engineering Environment → Linux / Edge
And that's a pretty big conceptual change.
But here's the interesting part about Windows
If you run a web-based engineering environment on Windows, it is still easy to think:
"Okay... this is basically my engineering workstation, except I'm using a browser Application."
On windows it was looking i am working on another IDE Application with F5 working to reload
Let's go in Details: Installation :
It was easy with proper link to prerequisites given at Installer itself
Project Creation : Tried to go in direction of VS code with Create Project or Workspace which is interesting
Language Supported :
Ladder & Structured Text ( Codesys also know People keep fighting only for these language so released with both )
I did not liked personally the color combination in Dark mode for Ladder but that's my Good or Bad taste
And the Most liked Structured Text 😂
Program Download and Online
It was pretty quick as it followed same steps what Codesys users are used to with three steps process Configure Device
Login
Start
I was still confused how should i open it in Web ..😎. And that's fair.
The browser doesn't necessarily change the architecture underneath.
Common Windows and WebBased for Codesys 4 are you kidding
Move CODESYS 4 to Linux...
And suddenly the idea becomes much more interesting.
Now you can have:
Linux server / Raspberry Pi
running the CODESYS environment,
while the engineer simply connects through a browser.
That feels much closer to what people mean when they talk about web-based engineering.
🐧 CODESYS 4 on Linux is where I became interested
This is probably the part I find most interesting.
You can run CODESYS 4 on a Linux environment rather than treating Windows as the center of the engineering world.
And then you start thinking about Edge devices.
Imagine a Raspberry Pi or industrial Linux box sitting somewhere in the plant.
Instead of thinking of it only as:
"This is my runtime."
you can start thinking:
"This device can potentially host part of my engineering environment too."
That's a very different architecture.
🐳 And then I added Docker...
This is where things got really interesting.
I packaged CODESYS 4 into Docker.
Now the architecture becomes:
Browser
↓
HTTPS / NGINX
↓
CODESYS 4
↓
Docker
↓
Linux
↓
Raspberry Pi / AMD64 Edge PC
And suddenly I'm looking at something I haven't traditionally associated with PLC engineering:
Codesys 4 Running as Container and Service in same machine at Same time
An engineering environment running inside a container.
That's the experiment that really caught my attention.
Because now the engineering environment itself becomes something you can package and deploy.
You can version it.
You can recreate it.
You can move it between systems.
You can deploy the same container architecture on ARM64 and AMD64.
That's where I think the bigger story is.
👍 What I really like about CODESYS 4
1. The web-based direction
This is probably my favorite part.
The idea of accessing an automation engineering environment through a browser is absolutely the right direction.
Especially when combined with Linux.
2. Linux support
This is a big deal.
Linux opens the door to:
Raspberry Pi
Industrial PCs
Edge devices
Cloud infrastructure
Virtual machines
Containers
And that fits very naturally with modern IT/OT architectures.
3. The familiar CODESYS ecosystem
CODESYS 4 isn't throwing away the entire foundation.
The compiler, runtime system and libraries remain an important part of the ecosystem.
That is important because engineers don't want to relearn everything simply because the UI changed.
4. Docker makes the concept even more interesting
Docker isn't necessarily something every PLC engineer needs.
But from an architecture perspective, it is fascinating.
Instead of installing an engineering environment manually on every machine:
Package → Deploy → Run
That's a very different operational model.
👎 Now let's talk about what I don't like
And this is where I think CODESYS needs to be challenged.
Because calling something CODESYS 4 creates a certain expectation.
You expect a major next-generation platform.
But some areas currently feel more like:
Version 1 of a new platform direction
rather than a fully mature next-generation engineering environment.
And I don't necessarily mean that negatively.
Every major redesign has to start somewhere.
But the gap between the vision and the current implementation is noticeable.
⚠️ The missing pieces matter
One example from the version I tested:
OPC UA is not available.
Online Code change
CTRL + F7 & F7 does not work
CFC & FBD is missing
Codesys 3.5 project migration
For a modern industrial platform, that's significant.
Especially when the conversation around CODESYS 4 is:
Web + Linux + Edge + Industrial Automation
OPC UA naturally belongs in that conversation.
So this is one of the things I would have liked to see available from the beginning.
📚 Library management also needs maturity
This was another area where I spent quite some time.
The underlying CODESYS ecosystem has a huge library story.
But when you move into the new Linux/web environment, library resolution and repository configuration become something you need to understand carefully.
I ran into situations where the project referenced libraries, but the environment wasn't immediately resolving them as expected.
That isn't something I would want an end customer to have to troubleshoot.
The next evolution should make:
Project → Libraries → Repository → Resolution
much more transparent.
🖥️ The Web UI still has room to grow
This is probably the biggest philosophical question.
If you're going to say:
"This is a web-based engineering environment."
then I think you need to go all the way.
The browser should not simply be a replacement for the desktop window.
It should provide capabilities that become possible because it is web-based.
Things like:
Better remote engineering
Multi-user workflows
Centralized project management
Role-based access
Collaboration
Version management
Remote diagnostics
Better deployment workflows
Integration with DevOps systems
APIs
CI/CD integration
That's where I think the real potential is.
🤔 So... should CODESYS have waited?
This is the controversial part.
My answer is:
No — but I would have called it an early foundation rather than expecting everyone to see it as the finished future.
Releasing it now allows the ecosystem to start building around the new architecture.
Developers can experiment.
Automation engineers can test it.
Edge vendors can integrate it.
And people like me can start putting it inside Docker and asking:
"What else can we do with this?"
That's valuable.
But if the question is:
"Is CODESYS 4 already the complete replacement for the traditional CODESYS engineering experience?"
I don't think we're there yet.
🚀 Where I think this could go
This is the part that excites me more than the current feature list.
Imagine five years from now.
You have an industrial Edge device.
It runs Linux.
Docker manages your applications.
One container runs your automation runtime.
Another provides your engineering environment.
Another provides your monitoring.
Another provides your historian.
Another provides your AI/ML application.
And the engineer accesses the whole environment through a browser.
Now we're talking about something much bigger than:
"A PLC IDE running in a browser."
We're talking about an Industrial Engineering Platform.
And that's where I think CODESYS 4 could become really interesting.
🎯 My verdict
If I had to summarize CODESYS 4 today:
Direction: ⭐⭐⭐⭐⭐
Concept: ⭐⭐⭐⭐⭐
Linux potential: ⭐⭐⭐⭐⭐
Web engineering potential: ⭐⭐⭐⭐⭐
Current maturity: ⭐⭐⭐
Feature completeness: ⭐⭐⭐
Docker potential: ⭐⭐⭐⭐⭐
So no, I don't think CODESYS 4 is a bad release.
Actually, I think it's a very important direction.
But I also think we should be honest about where it is today.
It feels less like:
"Here is the finished next generation of CODESYS."
and more like:
"Here is the foundation of what CODESYS could become."
And personally, that foundation is what I find exciting.
I've been testing exactly that combination:
CODESYS 4 + Linux + Raspberry Pi + Docker + HTTPS
And I'm going to keep pushing it further.
Because the interesting question isn't really:
Can CODESYS 4 run in Docker?
We already know the answer.
The interesting question is:
What happens when the engineering environment itself becomes deployable?
That's where things get really interesting.
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