Manage the collection of data in the History Manager

In the History Manager, you can manage the intervals in which the software collects the historical data and the number of data points to collect.

There are three data collections: Fast, Medium, and Slow. Each data collection has a calculated step interval (Interval), starting time (From), and ending time (To) that depend on the specified:

• Time step (dt) of the simulation

• Time-step multiplier (Multiple)

• Number of data points (Points)

The Fast data collection always starts at the most recent data point (From = 0 s) and proceeds backwards in time up to the calculated Fast ending time.

You save historical data in a snapshot. When you capture a snapshot of a simulation, you can choose whether the snapshot includes the historical data. See Manage historical data in the Snapshot Manager for more information.

You can choose to save historical data for only the variables that appear in a Trend or for all favorite variables in the simulation. Snapshots that include historical data for all favorite variables are often very large and may significantly increase the size of a simulation. You can reduce the size of your snapshots (and therefore the simulation) by saving historical data for only the variables that appear in a Trend. However, if you add new variables to a Trend and then revert to a snapshot that includes historical data for only the variables that appear in a Trend, then trend data is not available for those new variables.

Manage the collection of data

1. Open the History Manager.

   

   The three collections (Fast, Medium, and Slow) allow you to specify the frequency at which you want to collect data and the number of data points that you want to collect.

2. In the Multiple box, enter the time-step multiplier that you want to use for the Interval calculation.

   The Interval value equals the simulation time step (dt) multiplied by the Multiple value (Interval = dt × Multiple).

3. In the Points box, enter the number of data points that you want to include in the data collection.

   The From and To values depend on the Points and Interval values.

   For the Fast collection, the From value is 0 s (From = 0 s), and the To value equals the Points value multiplied by the Interval value (To = Points × Interval).

   For the Medium and Slow collections, the From value equals the preceding To value, and the To value equals the From value plus the Points value multiplied by the Interval value (To = From + Points × Interval).

4. In the Configuration section, select one of the following:

   • Trended variables: Collect and save historical data for only variables that appear in a Trend.

   • Trended and Favorite variables: Collect and save historical data for all favorite variables and any non-favorite variables that appear in a Trend.