Converting 1-D array of dynamic data to dynamic data

[jdb1986]

I am collecting 5 channels of data at 80kHz continuously.  I collect blocks of 800 samples/channel using DAQ assistant then index the data on the loop.  I need to display this data as one long continuous "block" so i append each array to the next.  I believe there has to be a better way of doing this.  I have attached screen shot of block diagram.  Any help is greatly appreciated.

-Jake

[GerdW]

Hi Jake,

you could do the adding directly in the DAQ-whileloop, no need for an additional loop afterwards...

[jdb1986]

I could use same loop but I want the acquisition to be as fast as possible.  I just need to know if there is a way to append my data that will use less memory because right now I am getting a memory full error.

-Jacob

[GerdW]

Hi Jacob,

you acquire 5 channels with 80kHz. Let's do some math:

5*80kHz = 400.000 samples per second.

400kS/s of DBLs = 400.000 kS/s * 8 Byte = 3.2MB per second

So you get 3.2MB of data each second. How long do you measure? In one minute you collect ~200MB of data, surely enough to force you into "Out of memory" messages...

You should think about:

- not using a While loop for measurement (as LabVIEW doesn't know the final array size before the loop starts)

- using queues

- using a proper Producer/Consumer structure

- not using the DAQ-Assistent for these data rates due to high overhead

- reading the knowledge base article on "Handling large datasets"

[Captain_Kirby]

GerdW provided some excellent advice!

Dealing with large datasets in LabVIEW is definitely an art which requires good programming practices.

You may also find this KnowlegeBase article useful.

Why do I get "Memory is Full" Error in LabVIEW?