wrote: Thank You.
Can you provide me some links to study about "principle of data flow".
Sure. Open a browser and type in "LabVIEW Data Flow". Pick several and read them. Then revisit your Block Diagram, which shows two processes (Data Generation and Data Acquisition) running in parallel, with no syncronization, no specification of "which comes first" or how they relate temporally to each other.
To do what I think you want to do, you need to be more "up to speed" with LabVIEW and how it works. Spend time (hours, at least) with the LabVIEW Tutorials (check the first page of this Forum). Take a Class. Study for a Certification Exam. Write (and run, and debug, and test) LabVIEW code. If you can, find a LabVIEW Guru and apprentice yourself for a while.
Bob Schor