How to extract data from PSA to Infocube and to the custome infocube ??

Hi.

I have created a Custom Infocube and created update rules between standard infocube and custom Infocube . The Dataflow is in 3.x . we have data in PSA . but now am unable to load data to Infocubes.  how to load the data to Standard infocube and custom Infocube . Can anyone please reply me ?  .