Manual Recalculation of Tags

One instance when you might want to recalculate data would be after the Historian Server restores a lost connection. During the period of connection loss, the collector buffers data. When the connection is restored, the buffered data is forwarded to the Historian Server.

When the buffered data arrives, the timestamps are earlier than the most recent calculation timestamp. Since the timestamp is earlier, polled calculations do not execute again with the new data but unsolicited calculations will retrigger. Hence, it is possible that calculations performed for tags during and after the connection loss might not be entirely accurate.

With the recalculate feature, you can recalculate all tags for time period during and after the connection loss. The recalculated tags will use the most accurate values in calculations.
Note: You can still use manual recalculation without automatic recalculation by disabling the automatic recalculation feature. To disable the automatic recalculation, set the Max Recovery Time to 0 on the Configuration tab of the Collector Maintenance screen for the specified Calculation or Server-to-Server Collector.

S2S/S2C collector Backfill procedure

With the Recalculate feature you can recalculate all tags for the time period during and after the connection loss. The recalculated tags will use the most accurate values in calculations.

During the period of connection loss, the collector buffers the data. When the connection is restored, the buffered data is forwarded to the Historian Server. When the buffered data arrives, the timestamps show earlier time than the most recent calculation timestamp.

Since the timestamp is earlier, the polled calculations will not execute again with the new data but the unsolicited calculations will re-trigger. Therefore, it is possible that calculations performed for tags during and after the connection loss might be not be entirely accurate.

Run S2C Backfill via Command line
ihServerToServerCollector.exe RELOADFILENAME=[file location] 
RELOADUSERNAME=[Username] <start time> <end time>

Example: C:\Program Files\Proficy\Proficy Historian\x86\Server>ihServerToServerCollector.exe RELOADFILENAME=c:\taglist.txt RELOADUSERNAME=\Administrator 1516875659 1516875785

See the following information about the parameters:
  • RELOADFILENAME: This is an optional parameter. File name should be absolute path, this file consists of the tag names, for which Backfill should be performed, each tag should be separated by new line. Any discrepancies in the file/no file exists/parameter not provided leads to Backfill all the tags related to the collector at the current time. After the Backfill, file gets deleted.
  • RELOADUSERNAME: This is an optional parameter. This username is used only when destination server is Historian for auditing purpose, and gets ignored when the destination is cloud.
  • TIMESTAMP: This parameter accepts Start and end time in seconds in epoch format for which Backfill should happen. https://www.epochconverter.com/