GLST returns an aggregate last statistics for an input variable.
The number of values that are aggregated is determined based on the frequency of the input variable.
Cx is an input conditional variable x.
The input variable frequency should be less than the result variable frequency. It makes sense to aggregate 5 one-minutely values into a 1 five-minute variable, but not the other way around.
V6091 = GLST(C6000)
where V6000 is a 15 minute variable, and V6091 is an hourly variable.