OPC HDA aggregation mode


I have a OPC HDA interface to Factory Talk Historian SE, an OsiSoft PI database. I do have some latency when using EasyChart with pens pointing to this historical database.

After 10-20 sec, the client is reporting:
“PI_208DAS_HDA (id=c6bdded7) Some of the requested aggregation modes are not available on the server. The backup mode ‘OPCHDA_INTERPOLATIVE’ will be used.”

… and then the read is finished after 2 sec.

What aggregation mode shale i use?

If i write OPCHDA_INTERPOLATIVE in the aggregation mode column i have an error in designer: “Invalid aggregation mode: OPCHDA_INTERPOLATIVE on pen:”. Now I got the same message
immediately in client, and the read is finished after 2 sec.