As opposed to data-archiving, snapshots usually show plant conditions at certain trigger events, e.g. when an alarm condition rises or a maximum peak of energy consumption occurs.
Snapshots are used to monitor the condition of a system, a machine or a building at certain moments. Thus, a periodic maintenance log reports e.g. all relevant measured values, operating hours and conditions at specific time intervals.
An error log presents data before, during and after an error event.
A peak load protocol logs all energy consumption values for occurrence of peak load events.