Timing problem with writing to file with analog input

[JoachimTaelman]

That is indeed the problem I am looking for since a couple of days. I thought I did something wrong with the settings or so.
You tested my program with a cdaq, as you said before that everything worked fine with you? If that is the case, the problem is somewhere with me (or my cdaq???).
I'm using labview 8.2. We have a full version. I will try to do some signal processing with labview. But I'm not experienced in it, so it could take me some time.

[JoachimTaelman]

JHoskins,

I already deleted the loop as 10Degree suggested to me.
I still have the same problem.

I printed the dt after the recording of the data (just after DAQmx Read). There is the dt already 0.00062.

Joachim

[10Degree]

Joachim,

I think you need to back up and establish that your hardware and system works as it should.  If you open and run the sample "Cont Acq&Graph Voltage-Int Clk.vi" and inspect the waveform data after the read, you should be able to see the correct sampling rate in the waveform.  If this basic test does not work, then it would seem that something is wrong with the hardware.

In the referenced VI, create an indicator for the waveform array coming from the "DAQmx Read.vi".  If you configure 1000 samples per second, you should see 0.001 as the dt value.  I attached the modified VI that you can use directly, or open and modify the example yourself.

-cb

[JoachimTaelman]

Thank you for your help!
We has solved the problem ourselves as it worked fine at 2kHz. By re-reading the manual, we discovered that the minimum sampling rate equals 1.611kHz (which was exactly the value we had). Now we are sampling at 2kHz and downsampling the result to 1kHz.

Thank you very much for your help and your time.

Joachim