I am having very similar problem like this one: [image] Arduino PLC IDE Freezes when Connecting to Opta PLC IDE After downloading the runtime environment and configuring the Modbus port as described in the Setup & License Activation Guide, I'm stuck at step 5. Whenever I try to connect the PLC IDE to the target, the Arduino PLC IDE freezes without any error messages. While the IDE freezes, another window popps up in the background which is listed as WinCommLibs in the task manager. Unplugging the USB cable unfreezes the IDE. Reinstalling the PLC IDE and IDE-Tools or loading a sketch from the classical Ard… Either IDE freezes, or I get error on the bottom right corner and WinCommLibs pops up. I tried all solutions I found on the web. I use IDE 1.0.6, the solution on the mentioned post is to install IDE 1.0.3 but that version also requires IDE Tools which I cannot find to download. I tried partitioning the memory, flashing, uploading code from the regular IDE... all that stuff works!, I can upload runtime, I get 2 new COM ports in the device manager but when the moment comes to connect to the device - it just doesnt happen! The default COM setup is 38400, 8,N,1 ... I tried playing with that also but zero success. Can someone please help me, I find it absolutely NOT serious from a company to sell PLC's with unusable software!

Ditto.... I have the exact same scenario as DigitalMeth describes above. There does not seem to be a standard solution available.. I don't have a Portenta to try, but don't see a reason to invest in one if the PLC IDE will not connect. This is frustrating to no end.

I solved the first problem by using the 2nd COM port as communication. So for example if when you connect it you get COM port 6, and after downloading the runtime environment COM 7 appears, try using that one. After that some other issues appeared but I was able to clear them through. To me this is completely whacky, I understand that maybe this product is still in optimization phase, but to me is more like hobby stuff. I wanted to utilize these controllers in a production facility for simple tasks, because they are cheap and sometimes I just need to control 3-4 outputs based on 3-4 inputs, but obviously what you pay is what you get. Hopefully in the future these bugs/ inconsistencies will be solved because I was really looking forward in using these controllers.

3 months later and IDE 1.0.7 but still the same problem. Has no one found a solution to the problem?

Then it feels like all hope is gone the solution is found. This worked for me at least Followed: https://forum.arduino.cc/t/opta-sill-not-connecting-to-plc-ide/1230775/15?u=jesper_jonsson and https://forum.arduino.cc/t/opta-sill-not-connecting-to-plc-ide/1230775/16?u=jesper_jonsson

Try to upload and run the Arduino IDE example STM32H747_System > QSPIFormat and then the entire Arduino PLC IDE Process

I had the same freeze when connect issue, Digging through all the post and your reply helped finally. It's just a matter of downloading using the lower port and connecting using the higher port. So many people have the same issue from what I can see from all these posts over months, how is this not addressed?

Having the same issue setting up an Arduino Opta Lite. Using Arduino PLC IDE 1.0.8. Tried both COM ports that shows up, tried regressing to Arduino PLC IDE 1.0.3 based some other forum threads. I have also tried the memory partitioning, but still struggling. So finnicky to just set-up this Arduino PLC... I can't even get to the point of trying to use it.

ins this case, that could help! [image] Arduino PLC IDE Freezes when Connecting to Opta PLC IDE I hope this finds everyone sane, I nearly lost my mind trying to resolve this issue. I was able to fix it by going to: and downloading and running the Opta Factory Reset tool: https://opta.findernet.com/download/OPTA%20Arduino%20Factory%20Reset_1.0.0_x64-setup.exe Then downloading Arduino PLC IDE 1.0.85 from: https://opta.findernet.com/download/Arduino-PLC-IDE-Installer_1.0.8_Windows_64bit.exe I am not sure where the underlying issue was, but this resolved 4 days of beating my head agains…

PLC IDE and Arduino OPTA - cannot connect

Development Tools PLC IDE

cmil413 July 9, 2026, 7:06pm 10

I believe that I have figured out a reliable solution for working with the Opta: Guide for Connecting to Arduino.

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PLC IDE and Arduino OPTA - cannot connect

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