Can not get the SlopedInterpolation Data

[sunny]

Hi Support team,

I am trying to read a Historical Variable node in C++ SDK Demo Server(V1.5.2 source version) .

1)Select the BuildingAutomation⇒AirConditioner_1⇒Temperature.
2)Stepped property is set to be False.
3)In the Client, I got the SteppedInterpolation data only.

In the V1.5.2 Demo Server, Stepped property node (SlopedInterpolation or SteppedInterpolation) has not be supported yet?

Now I want to get a SlopedInterpolation data by ReadProcessed() with AggregateType=Interpolative from the [Temperature] node,
Would you give me some advice?

Regards
sunny