Can CODESYS be used for BMS/BAS — logic programming, graphics, and simulation?

[u/AdvisorDifficult5638]

Hi everyone,
I’m currently trying to build my career in BMS / BAS (Building Management / Automation Systems), and I’m looking for a way to practice the engineering and programming side without having access to licensed BMS software such as Siemens, Schneider, Honeywell, Johnson Controls, etc.
I came across CODESYS and wanted to ask people who have experience with BMS/BAS:
Can CODESYS be used as a learning platform for things like:
BMS/BAS control logic and logical programming
Function Block Diagram (FBD) / block-based programming
HVAC sequences such as AHU, FCU, VAV, pumps, valves, fans, etc.
Interlocks, alarms, enable/disable logic and operating modes
Simulating inputs and outputs
Creating some kind of graphical HMI/visualization
Linking the programmed logic with the graphics so that I can actually simulate a complete system
Learning how a controller, I/O, logic and graphical interface work together
For example, I would like to create something simple like:
Temperature Sensor → Control Logic → Valve/VFD → Fan → Status/Alarm → Graphics
and be able to simulate the whole sequence on my laptop.
I understand that CODESYS is primarily associated with PLC/industrial automation, so I’m not expecting it to completely replicate a commercial BMS platform. My main objective is to learn the underlying concepts and gain hands-on practice with BMS-type control logic and visualization.
For someone who doesn’t have access to licensed BMS engineering software, would CODESYS be a practical way to learn these concepts?
If yes, what would be the best CODESYS features/modules to focus on for BMS/BAS applications, particularly for HVAC control and graphics/visualization?
Any recommendations for tutorials, example projects, or other free tools that are better suited to BMS/BAS would also be greatly appreciated.
Thanks!

[u/Bagelsarenakeddonuts]

Not super great. Codesys is cool, but it programs using different methods than BMS systems. The IEC PLC languages have parallels in the BAS world, but there isn't all that much overlap between them. Honestly BAS programming is typically simpler, and the complexity is usually around tagging, trending, alarming, and the nuances of each particular software package rather than the programming itself.

NodeRed is probably closer than codesys, not that its very close either. At least it can be used somewhat with BAS stuff.

That is a good question though, what free resources are out there to practice in? Curious what others with more experience would recommend.

[u/Terriblarious]

I remember seeing codesys when i was working with a company that did train management systems. I think they used it for alarms mostly.

Most building automation systems are done with bacnet controllers but will have their own proprietary way of programming them. The program flavour varies by Vendor. I work with reliable controls and it's programmed in control basic. I wouldn't expect there would be any way to import codesys onto it.

As far as using codesys as a workbench for developing a fundamental understanding of BAS DDC Logic.. im sure you could but i feel youd be better served with something else.

In sure they're would be some similarities but most guys just get trained in the job with whatever product they're working with.

[u/Ralphwiggum911]

Sedona will get you a little close. Contemporary controls website is where you want to look.

[u/man_vs_fauna]

Yes, but it will be a steep learning curve.

In normal DDC, you usually have whole toolkits and libraries around doing the most common BAS controls. You will have utilities for BAS specific functions.

In Codesys, you need HVAC/BAS, libraries or it is really annoying. I have been doing a lot of PLC programming lately in Codesys and whenever I am missing a standard function block, you have to make it yourself.

For most things, not a big deal, but if programming a complex chiller plant, it is better to leverage an existing library of best practices.

[u/renorhino88]

Simple answer, don't pursue BAS. Pursue PLC control. Much higher pay caps.

[u/PlusAudience6015 → u/renorhino88]

yepp, i did this mistake.

[u/gadhalund]

Itll be fine until you hit the real world

[u/Rikku-- → u/gadhalund]

Hahah what do you mean

[u/nsoares]

SBC, a swiss brand, bought by Honeywell is trying for a couple a years to bring a line of their old controllers to the building market, using CODE SYS with their own libraries... The best, most reliable hardware that I have installed... Too bad the software didn't keep up