03-20-2014 11:46 AM - edited 03-20-2014 11:48 AM
Dear all;
I write a labview program for isolated a signal from the mixture of two signals by using a reference input. I choose to use butterworth filter and apply it in bandpass mode. To determine the band width of the filter, I also use two tone measurement vi to detect the phase of the reference signal and the signal I want to outcome. Unfortunately, when I run my program, warming with message "waveforms have different dt value" is always show. How can I fix this problem?
Regards
03-20-2014 02:10 PM
Well you got a bad case of the DDT's and dt's
If you get rid of those express vis and use a vi from the waveform measurments pallette you won't get fooled by that dt that does not exist coming out of your filter
Of course you COULD use the Digital IIR Filter vi off the Waveform conditioning palatte and keep your dt info but that doesnt get rid of your DDT's
Here is one quick mod
03-20-2014 08:21 PM
Thank you very much. Unfortunately,my labview version is 2010, cannot see your attachment
03-20-2014 09:05 PM
Thank you very much, I have changed the VIs and then no dt value error. However, the measured phase for reference signal and all measurements for the filtered signal is wrong. How can I solve it.
Regards
03-21-2014 08:17 AM - edited 03-21-2014 08:18 AM
the butterwortth filter vi you are using removes timing information prior to filtering use the Digital IIR filter vi instead it works on the waveform as a waveform.