NI-scope waveform measurement

[ESD]

Newbie here.

I want to acquire a waveform from my digitizer using LabView and NI-scope and perform a scalar measurement on the same waveform.  Looking at the example niscope Ex Measurement Library.vi it appears that a waveform is acquired and displayed in a graph and then a second waveform is acquired and measurements are performed on it.  Is there an NI-scope subvi that performs a measurement and returns the acquired waveform along with the measurement?  Do I need to just acquire the waveform and perform the measurements using some other subvi's?

Thanks.

[adamg]

Hey Newbie ;),

If you remove the "niScope Multi Read Cluster.vi" from the "niScope EX Measurement Library.vi" and try to run it you will get an error that says:

An acquisition has not been initiated.

The "Multi Fetch Measurement Stats.vi" does not actually acquire a new set of points from the digitizer but instead uses the set the multi read VI has already acquired (look at the niScope help file for more information on Fetch VIs). The wording for these two VIs is subtly different in the help documentation. The read VI acquires a new waveform and the measurement VI obtains the (currently acquired) waveform. There are two VIs that acquire data and perform a measurement all within the same VI. They are called "niScope Read Measurement.vi" and "niScope Multi Read Measurment.vi." I hope this gets you pointed in the right direction.


Regards,
Adam
National Instruments