OPC UA: allow historical data access
allow historical data access with custom time ranges, like OPC HDA
We have a feature in the upcoming 1.2 release of the connector that will allow you to collect data from OPC UA tags that do not have current values but do have history. We would poll these every 60 seconds (default) to find new data.
Was that part of this request in any way? Can you describe in more detail what you would like as a feature that prompted you to vote for this time?
Armin Muljadi commented
Agree with Clint Ramsey. The feature to allow history recovery with custom time-range will help in recovering history that the connector is not able to cover, for example: time-sync issue between the connector and source that may cause the connector to miss the actual period where data was missing. The connector uses its own machine clock to recover history and the process could fail if the timestamp from source is leading or lagging. Can it be made that the connector uses the last timestamp from source? Please consider the improvement for the PI Connector for Siemens PCS7 as well.
Clint Ramsey commented
Hey Chris, the OPC HDA interface allows back-filling by entering a custom time range, ie start and end time. The OPC UA Connector with historical access does not allow this; it starts back-filling at the last time it lost connection to the UA server, back-fills and then begins its realtime historical retrieval. The customers would like the ability to back-fill using a custom timerange, like the OPC HDA interface.