"SI read.vi" problem

[trn1307]

Hi

I am using “SI read.vi” to measure the frequency and the amplitude of a sinus wave from frequency generator. The frequency measured by the sound card is four times small then the frequency from the generator. The configuration of “SI read.vi” is 16 bit mono, 44100 samples and the buffer size is 8192.

What is the problem?

Regards
Tommy

[Meister]

Hi Tommy,

I need to know a little more about your application to answer your question.
Would it be possible to attach a piece of simplified code?

Regards

Anders M
NIDK

[trn1307]

Hi

I have attached a simplified piece of code. I use a sinus generator as input and I have verified the signal with a digital oscilloscope.

Regards
Tommy

[chrisger]

Hi there

you need to supply any kind of timing information to the VIs doing frequency analysis, e.g. dt = 1/44100 s, otherwise these VIs assume dT = 1 s. Use the waveform datatype for time - related signals.

best regards
chris

[trn1307]

Hi

Can you post an example?

Regards
Tommy

[chrisger]

here it is...

best regards
chris

[trn1307]

ups

I am using Labview 7.0. Can you repost a version I can use ?

Regards
Tommy

[chrisger]

sure ..

have fun
chris

[trn1307]

Thank you very much.