measure signal level pass fail

[slipstick]

I have a signal which has a large pulse in it that varies from unit to unit. I want to measure the level of the pulse and then continue the test, and pass or fail the test later based in part on the pulse level. However, I can't trigger off of the pulse level change since it always changes (ends). How might I do this? See the picture.

Tay

[samantham]

Hello,

Are you limited to triggering the off the signals variable pulse?  Can you measure for a specific amount of time, get the maximum value, and then determine if it is a pass or fail?  I would suggest using the Max & Min vi located in the Programming then Comparison function palette to get the maximum value. 

If the application is limited to triggering, another option would be to use a Start or Reference Analog Window trigger.  The acquisition would trigger upon the signal leaving a set window, where the top of the window is set the lowest expected pulse level.  Please reference the Labview Help for the topic titled DAQmx Trigger for more details.

[slipstick]

Hi,

Yes, unfortunately I have to trigger, because the duration of each power level varies with time. Could be 1 minute or more variation.

I will look into the window trigger and post back.

Thanks!

Tay

[slipstick]

I have a passable solution I have posted here. I am stopping the measurements when the values exceed the limits, and take the mean of the measurements and decide which case to go to next. The program will still run away on rare occasions, but it is to be superceded by another program shortly. I will work on it as an exercise to learn how to fix the final issues in it.

Thanks for the help.

Tay