Extensions are found in several palettes, including alarm, control, history, and kitControl. Point extensions include the standard proxy extension (one for each point) and also optional extensions.
There are three main categories of optional extensions:
You typically add an extension by either:
A point’s Property Sheet lists extensions below its normal (frozen) properties. You can expand each extension to view and modify its properties.

The screen capture shows the properties for a Numeric Interval History extension that has been added to a numeric point (MidPoint).
If a point has multiple extensions, the station processes them in the same top-to-bottom order that they appear listed in that point’s Property Sheet . To re-order extensions from the top of the point’s Property Sheet, or on the point’s icon in the Nav sidebar, right-click and select Reorder.