2.5 Raw vs Interpolated Points
2.5 RAW vs INTERPOLATED points
Section titled “2.5 RAW vs INTERPOLATED points”In the following descriptions, reference is often made to Raw and Interpolated points.
Raw points are real data points that have been stored in the underlying data historian.
Interpolated points are virtual data points calculated from the raw points.
By default Interpolated points are used in charts and KPIs but the user can change this to Raw points. The reason for this is that the User Interface has no awareness of the number of raw points in a tag before it queries it. If the tag has very high frequency data (for example one point per second) then the returned dataset will be very large and could take a long time to load, or worse, crash the users browser. Conversely, if the underlying tag is very sparse, for example a safety valve position which only moves occasionally, there may be no data within the window requested.
To overcome this issue, Ingenuity 7 will default to 10001 interpolated points on a trend (this can be changed in the trend configuration) to ensure that a trend will always load and then the user can decide to switch to raw points.