This post has some information about how to troubleshoot Modbus RTU:
It’s using a different device, but a lot of the information would be applicable for the Flexy as well. The biggest difference is how to view the logs. In the Flexy, you want to enable serial debugging which is demonstrated in this post:
Hello @VIJAYSUNDAR,
We are facing the same issue with Melsec protocol.
Can you please let me know what was causing the issue and how it got solved?
Hi @Kshitij_Mayekar,
That’s a completely different issue. I would recommend creating a support case at https://support.hms-networks.com so that your local support team can help you with that.
Best Regards,
Kyle Reynolds