Sometimes the tag quality shows "Uncertain_InitialValue" but in Status>Device Connection, it shows as connected. Also I'm able to ping PLC IP address.
In this case if I restart Gateway Service then this issue gets resolved.
I want to understand why this happens and is there any procedure to resolve this without restarting gateway?
I've had this issue when the PLC is under heavy development and debug. I've gotten around it two ways. Turn off the automatic rebrowse on the OPC device connection or you can go into Modules as restart the OPC UA module.
There might be a better way, but once the PLC is in a near complete status, it doesn't seem to pop up again. (Rockwell PLCs mostly)
After turning off "Automatic Rebrowse" option, does this error occurs again?