How do i add array element after acquiring 8 samples from pulsatile signals and display it?

Question

Hello, LabVIEW Experts,
I'd like to do the following with the attached VI:
1)enter raw data(sampling frequency 333K/sec and 333K samples) into array1
2)the rising edge of the pusatile input triggers/starts the analog input(the first 8 points)
3)the 8 data points are appended/inserted into array2
4)front panel displays array and waveform of both array1 and array2
I know what to do in other langauges but i am having a hard time doing it with LabVIEW.
Please advise.
Thank you.
CK
Attachments:
tim continuation 020206.vi ‏90 KB

Answer 1

Hi CK-
The easiest method I can think of to perform this function is to sort through the array of data as it comes in and pull the necessary points.  I have attached a short example that shows how to graph the raw data and also to check two conditions:
Checking through the array, always check to see if one element in the array is greater than the previous (using shift register to store data)
Checking each point, always check to see if it exceeds the "Trigger Lvl" value
If both of these conditions are met (hence the AND "gate"), we break the While loop and save the iteration value.  We then grab values from the original array starting at this index and take "Length" number of elements.  Finally we present the array subset similarly to the original data.  This example uses a simulated square wave with noise, but reading an array from your DAQ operation should allow you to achieve the same results.
Hopefully this helps-
Tom W
National Instruments
Attachments:
Subset Suggestion.vi ‏79 KB