Analog input to modulate triggered sine wave analog output

I'm new to Labview and having trouble getting my app to program correctly.
I would like to use an analog input (AI) to modulate the amplitude of a
100 kHz sine wave and output the results to an AO. This is a real
time application: the AI will change every few 10's of ms so during one
"cycle" the amplitude will be modulated many times. Plus, the entire AO
will be triggered on and off with a digital input TTL trigger. The
waveform "cycle" will run continuously and so will the AI.
I've used an example included with Labview to read
the AI and a separate one to generate the sine wave and trigger it on
and off, but cannot combine the two together. I assume what I need to
do is implement a loop properly but when I try I can only trigger the
AO on and off and the AI does nothing or is static. I assume that the
vi just takes one point from the AI and uses that to determine the
amplitude of the sine wave, but doesn't "redraw" the sine fast enough
to respond to the AI changes.
Thanks,
Ethan

Hal,
I do not think I have Labview Realtime (unless it comes standard with the full version of Labview ). Do I need to have that? I have a 6251 DAQ board.
I've enclosed my program- it has the name of the original included program in its file name so you can see that I didn't do much to change it. I made some changes today (to make it non regeneration) but now can't get the AI to read at all. And I have no idea how to modulate the sine amplitude using the AI.
The sine wave works fine and triggers as needed. The one problem is that the sine wave doesn't end at the same point (phase) each trigger period so during the times between triggers the DC level on the AO is variable (which I do not want). Is there a way to end the sine wave at the same phase (at the zero crossing) while still triggering it with a digital input.
Thanks,
Ethan
Attachments:
ERB6-Cont Gen Voltage Wfm-Int Clk-Non Regeneration.vi ‏157 KB

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Message Edited by sandeep palreddy on 07-08-2007 12:46 PM
Sandeep Palreddy, Graduate Research Assistance
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151 Holdsworth Way
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