Update settings for Polling UA Server

[Seahhy]

Hi Team,

We are stuck with an issue and we want to find out what are the necessary settings that we need to update on the Unified Automation OPC UA Server in order to allow the client UA Expert and KepWare to Poll the point instead of getting updated by reporting.

Apart from the Publish Interval and the Sampling Interval on the client, what are the other necessary settings that need to be changed on the server? Also, is there a way to enforce client specified scan rate?

We want the timestamps to be updated regardless of the reading changes.
Hope you can advise soonest...

Thanks.

[Support Team]

Hello Seahhy,

the subscription mechanism of OPC UA is specifically intended to save bandwith and to only send data if a value or timestamp actually changed. If there's no change of the value, it is not necessary to transfer it, as the client already knows the current value.

You can set the monitoring filter of a monitored item to STATUS_VALUE_TIMESTAMP, but this only affects changes to the SourceTimestamp. This means that if the value changed to a different value and back to the previous value during a sampling interval, you would get a DataChange, but you would also not get the current value with each sampling interval.