Digial Waveform Graph- Samples

I am trying to use Digital waveform graph for my application. I could find a related example in labview Simple Digital Waveform DT Graph.vi. 
Tried to modify it a little bit with some control boolean switches but i cant change the number of samples which is possible in Example Vi.
Is there a way that i can also control the number of samples in x axis. because that doesnot seem to be possible when i convert for boolean array to digital.
Thanks
Attached Vi
Attachments:
Simple Digital Waveform DT Graph- mod.vi ‏14 KB

I have done some work in the attached VI
I have got three toggle switches a, b and c. I want to switch them based on timings for which I require a function where I can feed in the time based on the switching sequence. Just consider the switches in the form of truth table.
If none of the switches are turned On that means O000 time is going to be To/4 as shown in the fig attached. Similarly when the swtiches  a, b and c are in 100 fashion, then the time is going to be T1/2 as shown.
The attachment clearly shows my end application.
Take a look
thanks
Attachments:
Digital Wfrm.vi ‏35 KB

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