stdios-Device ENTERS slow poll mode (MELSEC - Address )

Hello Team,

We have installed Ewon Flexy 102 at one of our customer’s site.
Communication with Mitsubishi PLC (FX3U) has been established over MELSEC protocol.
Randomly after few hours/days, Ewon stops communicating with PLC and show “stdios-Device ENTERS slow poll mode (MELSEC - Address )” error in event logs.
Once Ewon is rebooted, it starts communicating with PLC again.
This scenario repeats multiple times throughout.

Can anyone please tell me what could be the possible reason causing this issue?


Hi Kshitij,

We do not support the Flexy 1xx series in our market, but if you create a support case at, a local HMS Technical Services engineer will be able to help you.

Best Regards,

Kyle Reynolds