The History Source Node Delta is a subclass of History Source Node from the seriesTransform module. It functions exactly the same with one exception. There is an additional boolean property named Delta Values which is used to configure whether to display raw totalized or delta values in the result set.
The component is located in the vykonProTransform palette.
Delta Values
If history values are totalized (ever increasing) setting delta values to true will return interval values (change of value) instead of the raw totalized values