Logging Data Fails NI USB 6009

[sevenOFnine]

Hello,

I want to record analog voltage values with an NI USB 6009 over some minutes.

Cause I have never used any NI hard or software I went through the LabView Signal express tutorial.

To test if the hardware works and to get familiar with SignalExpress (SE) I did connect a function generator to analog input 0 of NI USB 6009.

The function generator generates a rectangular function with 10KHz with 5Vpp and 2.5V DC-Offset (so that voltage level swings between 0V and 5V compared to signal ground).

The output is surveyed from a DSO.

I created a recording step in SE an configured the sampling rate to 10KS/s and number of samples to 1K. (I know that I actually need a higher sampling rate).

Here is the signal preview:

 

If I activate “Record While Running” recording stops with Error in DAQ-Assistent: -200279

 

The buffer size is chosen from recommendation of help file.

Any suggestions what to do?

If I increase sampling rate to 20KS/s and buffersize to 2K then signal looks more dissimilar to a rect than before, though sampling rate should be sufficient...

My OS is WinXP 32bit SP3.

TNX

7

[sevenOFnine]

Oh sry guys, of course i'm not doing a signal reconstruction, just connection the measurements points.

So the rectangle in second recording is expectable.

[BRennhofer]

Hi

I hope I understand you correct. You have two questions.

1) Why you get the error -200279:

The connection from USB device to PC is through USB. When you can not read fast enough your samples from the device, you get the error -200279

see folowing link.

http://forums.ni.com/t5/Dynamic-Signal-Acquisition/Error-code-200279/m-p/1322481

2)Why you get a triangle signal:

see folowing link. The issue is your signal and the smpling rate are not in the right ratio. See the nyquist theorem.

http://forums.ni.com/t5/Dynamic-Signal-Acquisition/Error-code-200279/m-p/1322481

I hope this information can helps.

Best regards

Bernhard
NI Munich, Germany