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Starting data acquisition at some specific time

Hi, 

 

I have asked this question a little differently before and got some answers.

I want to have a button that the user can click and start acquiring data. So my labview is working and at time T the user clicks and the data will be collected to be processed.

 

I have been told that I can collect the data from the beginning and then use extraction portion of the signal. But for some reasons it has its own problems. I was wondering if anybody know any way that the data acquisition can start manually. (my labview should be working and I am sending some analog output at  time 0. Just the analog input should be collected by demand.)

Any idea?

 

Thanks,

Baran.

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Baran,

 

Here is an idea:

 

1. Create your tasks for AI Read

2. Set Sampling Clok to Finite Samples

3. Use an Event Structure. Add an Event Value Changed - Button "Start Acquisition". In this event tab you'll: 

3.1 Start task (not necessary in daqmx 9.1)

3.2 Read Samples - same number as defined in 2.

3.3 Stop task (not necessary in daqmx 9.1)

3.4 Process data or whatever

 

That's all.

 

Paul

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Just for the record, I have been told by one of the NI support group that I can use case structure and put my DAQ assistant/processing data in that, and have a push button wired to case structure to start acquiring data leave the false part of case structure empty. That worked. 

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