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Disadvantages of using DAQ Assistant

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I need to sample 2 analog inputs continuosly at 5-10Khz and then use a combination of Producer Consumer and State Machine for real time data processing.

 

In most of the example which I saw, people always use the groups of subVI for data acquisition. Although, I know how to setup an data acquisition using the subVI, I like to use Express VI DAQ Assistant to perform the data acquisition.

 

Does any one know of the disadvantages of using express VI in my case (See 1st Line)?

 

 

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If you open the block diagram of the express VI (right click on the icon and select open block diagram) you will see the differences. In summary it is potentially less efficient  to use an express VI as it has to check if it is first call, or if you have selected stop etc every time it is called.

 

However, depending on your application this is not always an issue. Open the VI and take a look as that is something you will need to make a judgment on.

David
www.controlsoftwaresolutions.com
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Oh Yes, I saw the block diagram and it looks more complicated than its required to. Hence the express VI can be more inefficient. On the other hand, for my appplication (2 Analog inputs sampled at 5-10KHz each) do you think it can make a difference?

 

Timing is very critical in my program. Hence I am using Producer-Consumer with Queues for implementing parallel loops for real time data analysis. 

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Solution
Accepted by topic author Neuropotential
Using an express VI will slow execution time and consequently your loop iteration time due to the associated overhead.  If you are concerned about the timing of your program, then you should strongly consider using the DAQmx API VIs.
Regards,


h_baker
National Instruments
Applications Engineer
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Ok Thank You.
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