I have a strange case.Compression does not work while loading data from OPC HDA ("history recovery only" option).
Below is a sample of data and settings for a given point. Any advice?
Thanks in advance
When performing history recovery through PI OPC HDA interface by using the /hronly (history recovery only) switch, the interface will apply exception to the data. However, compression would not happen when filling a gap in history recovery mode.
Both exception and compression will be performed on the data when the interface is collecting snapshot data (i.e. not history recovery).
This is due to how the PI Server handles compression. It only applies to data sent in-order. Otherwise, it is not able to calculate the compression slopes.
Thank you very much for the explanation. I suspected it was such propery.
Retrieving data ...