Cut off frequency of a low pass filter

[KDGREAT.]

Hi everyone,

I need to develop a labview to determine the cut off frequency of a low pass filter. The filters have already been simulated but I have to write a labview code to determine their cut off frequencies.

I have attached the code I developed but I will welcome an improvement or a new code. Also how can I modify the program to measure the fiters by just locating the files (filters) and automatically measure their cut off frequencies without writing the code for each of them

any suggestion will be highly appreciated.

Thanks.

kdgreat

[jyang72211]

Can you attach your dlsimfilter2.vi as well?  When you said files (filters), do you mean the filters' transfer functions in files or DSQ coefficients in files?  Attach a file that you are referring to as well.  

[KDGREAT.]

thanks. the file are to be traeted like a blackbox. there is no access to the block digram bcos it is pass worded. the task is just to write a program to interroge this file (filter) 

[johnsold]

This sounds like a school assignment?

Why not do it the same way you would measure a physical filter in the lab?  Create a swept frequency signal as the filter input.  Look for the freqeuncy where the output is 3 dB below the passband level.

Lynn

[jyang72211]

I agree with johnsold

[kufre2eng@yahoo.com]

Send me your final work to review and provide solution

[RavensFan]

"Review"??  Or to use to pass off as your solution for your assignment?

[kufre2eng@yahoo.com]

how was the problem solved

[pobrepablo1]

Nobody is going to do your homework for you. 

[kufre2eng@yahoo.com]

We need to share knowledge not doing ones home work as you may think.