06-06-2016 03:26 PM
Hello,
I am using a DAQ (NI USB 6351) to record my signals. AI 0 records a sinusoidal measurement signal and AI 4 is a trigger ramp signal. I’m trying to synchronize the start of the measurement signal to a voltage level based on the ramp signal. In other words, I would like the measurement signal to start recording and save to a text file only when the trigger signal satisfies the voltage condition of: .
Currently, the measurement signal is not triggered properly, observed with the recorded voltage level from text file, where the starting voltage (at time = 0 sec) ranges from 3.5 to 2 V.
Is this problem caused by DAQ2 (Received ramp signal) sending in data faster before the comparison operation has been carried out? Or ..? How to fix this ..?
Please see attachment for the current VI build.
Thank you for the help,
Best,
06-06-2016 02:45 PM
Hello,
I am using a DAQ (NI USB 6351) to record my signals. AI 0 records a sinusoidal measurement signal and AI 4 is a trigger ramp signal. I’m trying to synchronize the start of the measurement signal to a voltage level based on the ramp signal. In other words, I would like the measurement signal to start recording and save to a text file only when the trigger signal satisfies the voltage condition of: 2.5 V <= Measurement signal <= 2.7 V.
Currently, the measurement signal is not triggered properly, observed with the recorded measurement signal from text file, where the starting voltage (at time = 0 sec) ranges from 3.5 to 2 V.
Is this problem caused by DAQ2 (Ramp signal) sending in data faster before the comparison operation has been carried out? Or ..? How to fix this ..?
Please see attachment for the current VI build.
Thank you for the help,
Best,
06-06-2016 06:03 PM
Your code makes no sense. The dynamic data out of the first comparison has only two possible values (coerced back to a DBL number of either 0 or 1), so comparing it to a fractional number is pretty pointless.
Why don't you use more defined datatypes instead of dynamic data?
06-06-2016 08:06 PM - edited 06-06-2016 08:07 PM
In your DAQ Assistant, there is a Trigger tab. Use that to set up an analog trigger on your signal at the level you want.