ProSoft Technology MVI56-AFC - Manual (Page 139)

MVI56-AFC ♦ ControlLogix Platform Events
Liquid and Gas Flow Computer User Manual
ProSoft Technology, Inc. Page 139 of 316
February 25, 2011
9.6 Period-end Events
A "period-end" event is detected by the wallclock. There are two such:
a) "End-of-hour" occurs when the minute of the hour steps into the "End-of-
hour minute" of Site Configuration.
b) "End-of-day" occurs when the minute of the day steps into the "End-of-day
minute" of Site Configuration.
A wallclock change that skips forward over an end-of-period minute will cause
that period-end to be missed, and a change that skips backward over that minute
will cause that period-end to be repeated, so wallclock adjustments should be
performed at times well-removed from either end-of-period minute.
Though a period-end event is not recorded in the event log, it does cause
archives and resets to be scheduled for all enabled meters according to their
configured "period-end" Archive Options. Archives and resets scheduled by
period-end are delayed in their action until at least one meter scan has occurred
after the event (the archive data accumulation that takes place at the end of the
meter scan also records the latest timestamp, so the written archive then reflects
the fact that the period-end has occurred).