Filtering my displacement signal

[krithika]

Hi Dev

I tried increasing the sampling freq to 10000 but no help!

When i run the VI (just analog input), with no analog output (ie not feeding the sine wave), i see the offset.

So how do i do get rid of this initial offset? I need help combining the finite acquisition to subtract the offset and then perform the actual acquisition. The test.vi that i had attached is incomplete, can you suggest how i can do the same?

Pls Help!!

Thanks

Krithika

[krithika]

Hi

Do you guys have some suggestions on FFT?

I attached a VI earlier withFFT.vi.

Thanks

Krithika

[devchander]

Hi Krithika,

The simplest way to cancel initial offset is to put the values read in first iteration into a shift register and subrtact all the subsequent values from it

If not do a finite acq and subtaract all future values from that acquired values

Look at attached VI's, they demonstrate both logics.

Regards

Dev

[krithika]

hi Dev

I tried implementing the Vi that you sent me - i am getting an error- no buffer trasfer is possible.

I actually changed the filter settings in SCXI 1121 from 4hz to 10Khz and i am able to see a sinusoidal wave. but it has some distortions at the peaks. I have attached my output. I tried using a butterworth filter (lowpass) to filter the signal. But my display of the filtered signal is not a sine wave.

Pls help me out.

[devchander]

Hi Krithika,

Of the two VI's i sent, which one gave this error ?

regards