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PXIe-5646R Example "RFSA Stream IQ to Disk.vi" -Error -369019



while trying to run the example "RFSA Stream IQ to Disk.vi" i get an error

after a few seconds with the PXIe-5646R and with the settings in the main vi:

IQ Rate: 125 M S/S

Total Samples: 12500000

Max. Samples per Block: 1000


Error: -369019

in niRFSA Fetch IQ (1DI16).vi :

"The requested data has been overwritten in memory.

Therefore, it is no longer available for fetching."



-What does this mean?

(-Is there a buffer underrun? -Ho can i appropiatly configure it to run? )



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Message 1 of 7

Hi PXIeuser !

The message mean the data in memory has not been read fast enougth and the new data coming from the digitizer has overwritten the old data.

I thin you must increase the number of sample per read. 

1000 sample per read @ 125 Ms/s = 125000 loops per second to read each buffer ! Impossible on host computer !

try to read a power of 2 to match with the bus size and about 2 mega samples ou 4 MS.



Il a LabVIEW, il a tout compris !
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Message 2 of 7



thanks for your help:


i've tried Max. Samples per Block with

4194304  (= 2^22 Samples =approx. 4 MS)




2097152 (=2^21 Samples = approx. 2 MS),


but i get the same error.


My System:

Chassis: NI PXIe-1082
Controller: NI PXIe-8880
VST: NI PXIe-5646R

OS: Win 10 Pro LabView 2017, 32 Bit


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Message 3 of 7

Ok i don't look at your example before but now i can tell you this VI is not the good way for high data throughput.

Give a try to this example : http://www.ni.com/example/30895/en/

Maybe you will have to modify some values but it is the good architecture to record data. 

To resume, you must look at the fetch backlog which is the amount of data available on the onboard memory and fetch data when the desired number of sample is reached.

Oh an other thing : don't try to stream back data to VST with RFSG, it is not supported !



Il a LabVIEW, il a tout compris !
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Message 4 of 7

If you're trying to stream full rate to disk, then you should consider this example.

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Message 5 of 7

Many thanks!!!


This example ("Streaming Host Example for the NI PXIe-5644R/45R/46R ")


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Message 6 of 7


I hope you are doing good.

I don't find the "RFSA Sream IQ to disk" Example. Can you provide me with that?

I need to stream IQs directly from the device buffer to the hard disk bypassing the Windows, LabVIEW, and TDMS buffers. Hope this example will help. 

Thank You.

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Message 7 of 7