Contiguous Waveforms using an Oscilloscope

[slucas]

hello one and all, i am grabbing discrete waveforms from an oscilloscope. each waveform has approximately 5 periods at the frequency i am studying and there is a lot of noise that i want to filter. so i want to apply a IR notch filter to do this, however, those filters require prior waveforms for the frequency rejection. the waveforms are snapshots from the scope and so i get the error "20352: Current and previous waveforms are not contiguous." so how can i use FIR or IIR filters with my scope?

thanx in advance.

lucas

[DFGray]

That really depends upon what oscilloscope you are using.  Most modern oscilloscopes have the capability to continually stream data to a host computer.  Bandwidth is an issue, so board based scopes (like the NI ones ) will allow you to stream at higher acquisition speeds.  If you are using an NI scope, check out the example niScope EX Fetch Forever.vi.  IVI based scope APIs should use a similar mechanism.  I can't comment on GPIB/SCPI based scopes, since I have not used that API for years.

Let us know a few more specifics - scope model, acquisition rate, API used, etc. - and we can help you more.

[slucas]

ok, i think i got it working nicely.  since i was grabbing discrete waveforms from the scope i had to create a waveform.  the waveform's dt was not to difficult, but the t0 between waveforms was a little tricky.  once i had that coded properly, the IIR filter works great.  i was afraid to go continuous on the scope because i didn't want a computation bottleneck somewhere causing the thing to crash.  thank you for the help.  lucas