The answer is:
- Yes if the SourceTimestamp has changed (this is normally the case)
- Not to my knowledge, if the source timestamp has not changed.

You need to use "data change filter" and specify a triggering mode that is different form the default.

In principle, the code will be like the example here: opclabs.doc-that.com/files/onlinedocs/QuickOpc/Latest/User%2...e%20nodes%20with%20filter.html

except that you will use UADataChangeTrigger.StatusValueTimestamp.

Note that it is not necessary to use this approach just to "assure yourself" that the value is still coming from the server and has not changed. OPC UA and QuickOPC have enough mechanisms to assure that you either get the changed value, or an error indication.

Best regards