DAQ Assistant

[roadrunner23]

Hi,

How can i have optimal data aquisition using DAQ Assistant during a process that lasts around 2 hours but i don t know exactly how long. Should i use continous or finite sampling? Is there any given situation that calls one of these 2 modes?

Thanks in advance!

[crossrulz]

If you want constant data for the undefined amount of time, you want Continuous Sampling.  Finite Samples is only useful for capturing small windows of data (like 100ms worth of data).

[roadrunner23]

And should i place the DAQ in a while loop (for continuous sampling)? Because after the aquisition i need to save the data into a file and i use Write to Meas file.Vi

Thanks!

[Dennis_Knutson]

Yes, of course you need a while loop.

I would suggest that you use a producer/consumer architecture and save as you acquire.

[roadrunner23]

I understand, but what do you mean by producer/consumer architecture?

Thanks!

[Dennis_Knutson]

It's a common design pattern. Look at the examples and templates that come with LabVIEW. At the simplest level, you have one loop (the producer) that just does the acquisition and possess the result to a queue. A second loop (the consumer) reads the queue and writes to file.

[crossrulz]

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@Dennis_Knutson wrote:
I would suggest that you use a producer/consumer architecture and save as you acquire.

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Depends on the format the OP wants the data in.  I recommend using a TDMS file since DAQmx makes this way too easy for you.  In the DAQ Assistant, there is a Logging tab.  Go there and enable the logging.  DAQmx will stream your data straight to a TDMS file.  You don't have to do anything else and it is highly efficient.

For any other file format, you should use the Producer/Consumer.