Hi everyone, i bought the opta over half a year ago. That time it was unable to connect to the arduino plc ide as it was not supported. Due to having other resources at work (i work as plc software engineer in automation) i didnt try the opta since then. Today i was in the mood to try it out again, but the opta still cannot connect to the plc ide. I downloaded the newest version IDE, downloaded and installed the PLC-tools. I have uploaded the first scetch from the arduino ide, connected the opta, selected the right port (same as in the arduino ide) run the first setup, changed the port in modbus settings to 247. But still when i want to connect the IDE freezes a d crashes, or it gives [ERROR] in the bottom right corner without connecting and without giving an actual error code or message. If arduino want to get serious about this they still have a long way to go. Has the plc ide or the opta turned into abandonware? I see a lot of topics about this from the last year without an actual solution. Did anyone manage to connect the opta to the plc ide?

This is 100% the solution! Key steps NOT included in Arduino's PLC IDE Setup doc are the memory partitioning, using Automatic (Bootloader) port for first setup download, then using the HIGHER port for connecting. Thanks a million @dscialabba!

after struggling for 3 days this work for me

Ich habe auch schon Tage damit verbracht. Es hat schon einmal für etwa drei Tage funktioniert. Es ist eine Katastrophe.

Thank-you for your comprehensive solution. I was expecting better from the Opta...

I followed all the instructions as described, but when I try to connect, an error appears in the bottom right corner. [Screenshot 2025-05-10 134955]

Hi. This did not work for me. I have an Opta RS485. Which version did this work on?

Hello @dscialabba I'm using an Arduino Opta AFX00002, and I'm still having issues with license activation and connection in the Arduino PLC IDE. I followed all the steps shared in the setup guide and forum (including memory partitioning and QSPI flash formatting). The device reaches the message: QSPI Flash formatted! It's now safe to reboot or disconnect your board. After that, I restarted the Opta (tried both pressing the reset button and reconnecting the USB). However, when I try to connect in the Arduino PLC IDE, the IDE freezes, and after some time I just get an "ERROR" message without much detail. Here’s what I’ve done: Used COM12 for both the Arduino IDE and Arduino PLC IDE. Tried uploading the memory partition example from Arduino IDE successfully. double-pressed reset when necessary. Reinstalled the IDE. Here is a screenshot of the error (when it totally freezes): [image] these are the ports I have (I used COM12 for the configuration on arduino IDE and arduino PLC IDE): [image] Any advice, workaround, or fix would be PERFECT. Thanks in advance!

Hey guys! I finally could make it work on my AFX00002 (for those that couldn't make it with the instructions posted above): I contacted support, and they sent me a .zip file . It includes: A sketch to reformat the memory partition. A certificate file, required during the process. opta_memory_partitioning.zip (62.8 KB) Unzip the contents and place both files (the sketch and the certificate) in the same folder. Open the .ino sketch using Arduino IDE version 2.3.5 (or compatible). If multiple COM ports appear (due to previous attempts using PLC IDE), Select the port with the lower number (e.g., COM11) to upload the sketch. Upload the sketch without making any changes. Once uploaded, open the Serial Monitor. Do not type anything. Wait until the following message is displayed: It's now safe to reboot or disconnect your board. Open Arduino PLC IDE (v1.0.8 in my case) and go to the Other section. Select the COM port available, then click Download — if the download fails, continue to the next step. Double-tap the reset button on the Opta using a clip or pen tip. The green LED above the reset button should start blinking slowly. A new COM port (e.g., COM12) will become available. As per the official documentation: “If the following message appears during the download procedure, double-tap the reset button using the tip of a pen or a similar pointed object. The LED above the reset button for Opta™ or the Digital Outputs LEDs for Portenta Machine Control will start blinking, indicating that the device is ready to be flashed with new firmware. Click the Download button to begin the process again.” In PLC IDE, go to Project > Refresh Current Target to update the available ports list. [image] Select the new COM port (e.g., COM12) and click Download Runtime again. Once the runtime is successfully installed, go to Online > Setup Communication. Select the COM port with the HIGHER number (e.g., COM13) and click OK. Click the Connect button Keep following: https://docs.arduino.cc/software/plc-ide/tutorials/plc-ide-setup-license/ I hope this helps others struggling with the same issue. Let me know if any step is unclear!

After much frustration... This is what solved the issue for me. I can finally connect to the Opta! What I find odd though, is that the IDE is saying my Opta 485 has WiFi...

Opta sill not connecting to plc ide

Official Hardware Opta

cmil413 July 10, 2026, 1:35pm 46

Hello, everyone.

I believe that I have found a reliable solution for working with the Optas: Guidance for Connecting to Arduino Opta using Arduino PLC IDE.

Topic		Replies	Views
PLC IDE cannot connect to OPTA Opta	39	12121	May 7, 2026
Can not connect to my arduino opta plc how to solve it Opta	5	157	July 9, 2026
Upload to Opta and communication errors with PLC IDE Opta	4	926	March 30, 2025
Guide for Connecting to Arduino Opta Opta	3	715	July 16, 2026
PLC IDE and Arduino OPTA - cannot connect PLC IDE	9	2336	July 9, 2026

Opta sill not connecting to plc ide

Related topics