Initial transient while filtering

[aravind_phd]

Hi All,

I'm presently acquiring data (DaqMX) of a mechanical system and i need to use a continuous realtime bandpass filter in which I can control the upper and lower cut-off frequency depending upon the frequency of the signal.

I tried using the butterworth filter while the acquistion is in a while loop. The problem I'm facing is that i'm getting a transient in the filter output everytime new samples are acquired. Is there anyway I can avoid the initial transient.

I have found that the transient can be avoided if i filter the signal off-line, after reading the data from a file.

Thanks in advance

Aravind

[Dr._Imad]

All the filters vi's have an boolean  (initialize / not initialize).  In a while loop as data are collected, the boolean should be set to True (initilaize) for the fiirst iteration (i=0) , and to False for  the next iterations

[aravind_phd]

Thanks Dr.Imad for the reply.

What is the difference between pt-by-pt filter and array type, can i avoid the initial transient problems by using pt-by-pt filters? Thanks again for that tip, I will try that and let you know the sollution.

Aravind