Hi Gmadhu,
You do generate that signal by using the: "Simulate Arbitrary Signal.vi" Located at Functions Palette>>Programming>>Waveform>>Analog WFM>>Analog WFM>>Generation.
The Express vi allows you to define your own waveform by defining a look up table.
You can then hook up the Dynamic signal output of the Express vi to: Convert from Dynamic Data.vi and generate single point.
This in the whileloop with the appropriate loop rate will accomplish your desired waveform.
Hope this helps
Van L
NI Applications Engineer