Hello I do have a Digitizer with following setup: - Sample Rate = 20000000 - Record Length = 12000000 This works fine so far and gives me a sampling time of ~600ms. Where the problem occurs is when I like to display the signal in a graph. Here I get the error message "run out of memory". Therefore I used the express vi "Sample compression to reduce the data by a factor 10'000 for example but this still does not work when I set the input of the "niScope Fetch WDT.vi" to the value "-1". It works when I set this value to 1'000'000 for example but this is no solution because I do not the complete signal up to ~600ms! I also can not reduce the sampling rate of the digitizer because I will loose the accuracy of the measurement. How can I solve this issue? Thanks in advance

The NI-SCOPE examples contain sample code explaining how to fetch the data from the scope card in chunks (e.g. niScope EX Fetch In Chunks.vi). As has been previously mentioned, there are tuturials on how to manage large data sets in LabVIEW, including one in the LabVIEW help and one here. Between these three sources, you have sample code to fetch from your scope card in chunks, decimate for display, and display without running out of memory. This is the algorithm and method used by the NI-SCOPE Soft Front Panel.

LabVIEW

Sample Compression

Solved!

Author

Hello DFGray

thanks for your reply with the link to the examples. I will have a look on it in order to solve it!

Thanks

Message 11 of 11

(284 Views)

LabVIEW

Sample Compression

Re: Sample Compression