design digital bandpass filter

[sfhj]

hi, i need to design bandpass filter to pass for example from 1 t0 40 hz and then detect band inside that one from 4 to 15 hz to give alarm

[Dennis_Knutson]

And exactly what are you having problems with? You have the Filter palette on the Signal Processing palette. You even have an Express function. Have you even looked at any of the examples that come with LabVIEW?

Same applies to the spectral analysis functions.

Edit - how many posts are you planning on the same subject? No more tnan ONE!

[sfhj]

yes i looked in the examples i ask about making alarm when detecting band inside the big one

and what subject do you mean ,is not it allwed to ask more than one question ...did you buy this forum

[Coq_Rouge]

@sfhj

Good questions draw good answers, and your hijacking of a thread from 2003 has caused some confuse. You are welcome to ask any question, and start any thread you want. But normal forum etiquette rules will apply. Like do not cross-post the same topic, stay in one thread.

[sfhj]

i did not repeat it was another question i asked about two filters difference and now i ask about bandpass 

i think they are different

[sfhj]

i make bandpass filter using elliptic to pass only square wave

then input is sine and square but no output

[Tanya_V]

If I understand correctly you want to bandpass filter your data. And then within that data you want to check a narrower frequency band to trigger an alarm. 

To do this you could apply another filter to the output of the first bandpass filter. Then check the level of this signal to trigger the alarm. Is there any more specific information you were looking for?

Have a great day!