Plotting successive triggered signals from Trigger and Gate VI on top of each other

[Sassy363]

Hey all,

I'm currently writing a unit impulse recorder VI and I am using the trigger and gate VI to extract the portions of the wave that I want.  I have the trigger and gate vi inside of a while loop with the data available output set to the stop if true condition.  What I want to do is plot the triggered signals that come from the trigger and gate VI on top of one another on a chart, so that all signals are displayed. 

The problem I have now is that only the current signal is displayed on the waveform graph.  I think I need to get the triggered signals into an array that will replace all of the time stamps associated with those triggered signals to start at time zero.  I have tried different vi's associated with array manipulation but have not been able to figure out how to send the signals into an array that will allow me to plot the individual signals.  The data manipulation I am performing is to be in real time, and there are an infinite number of acceptable triggered signals, so initializing an array with a certain amount of positions for the incoming waves would not be of good use unless I can initialize a very large number of positions.  If you can provide any insight that would be great! thanks!!!!

Jen

[Nadim R]

Hi Jen,

If I understand your problem correctly, you would like to plot the trigger, gate and the current signal in one simple plot.  The easiest way to do that would be to use a waveform chart, however, you can still use waveform graphs.  The only concern would be to save previous data on the waveform graph- to do that, you can use a shift register that saves the previous data from previous iterations (this method could be a processor consuming).  I assume your trigger and gate VI as software based-it therfore does not have as much resolution as a HW trigger.  To summerize, I think your best bet would be to use waveform charts and plot all three signals on one chart.

I hope this helps,

Regards,

Nadim
Applications Engineering
National Instruments