Filtering of noisy signal

[qinn]

I'm currently work on this project which I connect the output signal from photodetector to Agilent DSO6014A oscilloscope. But the signal displayed on oscilloscope is too noisy. I already interface oscilloscope to laptop via USB. However, how can I programmed the application to filter the signal and display it on excel sheet? I need to use a bandpass filter just to get the signal I need.

[shrekt]

Hi,

you can find filter vi in signal processing pallete.

see  attached image

and search forum to write a signal in excel.

Regards,

[Norbert_B]

You better include a highpass filter in hardware before acquiring samples with your oscilloscope. This is due to aliasing which probably occurs. Aliasing depends on the sample frequency of your signal, in this case your time resolution you selected in the scope.

Connecting any laptop to the scope does/should not influence noise at all. So if you already acquired your signal, you have to filter the signal in software. You can use a LabVIEW VI to do this on your laptop. You need to have the signal from the scope though....so a working datatransfer is mandatory.

You can also look if the scope supplies software filtering before you transfer the data to the laptop.

hope this helps,

Norbert

[Edit]: Enabled link to wikipedia 

Message Edited by Norbert B on 01-07-2010 01:38 AM