filter problem

[dekydek]

Hi!

I just wanted to do a filtering (with the digital IIR filter) on a data acquisition performed with DAQmx drivers, but i have a problem: at each new acquisition (every second), the first value seems to be set at 0 by the filter. So what's the solution?

Thank you for your help!!

[gwd]

I can't look at your vi because it's in 8.0.

There may be some filter types which necessarily have this behavior. See the Labview Analysis Concepts documentation and in particular look at the definition of the IIR response. If one particular coefficient (b0) is zero for your filter you will see that behavior.

Note that you would see exactly this behavior for an analog filter in some cases;  driving a low-pass filter with a step function at t = 0 would give zero output at t = 0+.

[rpursley8]

Message Edited by rpursley8 on 06-08-2006 04:22 PM