What type of data will not be captured if the Historian is not running?

When the Historian is not running, real-time data will not be captured because the primary function of the Historian is to continuously collect and store data from various sources in real-time. This includes current process values, events, and alarms as they occur. If the Historian service is offline or down, it cannot perform this task, resulting in a gap in the data capture for that period.

In contrast, archived data, historical data, and backup data refer to information that has already been collected and stored when the Historian was functioning, and these types of data would still exist regardless of the current operational status of the Historian. Thus, only the real-time data, which is dependent on the active operation of the Historian for collection, will be affected if the system is not running.