About this task
When the connection between the collector and the
Historian server is lost, the collector buffers data. When the connection is lost, the
buffered data is sent 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 are not performed again with the new data (unlike the
unsolicited calculations). Hence, it is possible that calculations performed for tags
during and after the connection loss might not be entirely accurate. Therefore, after
the Historian server restores a lost connection, you may want to manually recalculate
tag values. The recalculated data will use the most accurate values in
calculations.Note: If you want to disable the automatic recalculation, set the
Max Recovery Time to 0 in the
Configuration section of the Collector
Maintenance page of the collector.