FIR coefficients

[shirin91]

hi

i'm trying to design FIR filter for DDC. i have tried "Parks-McClellan.vi" and i used only forward coefficient to my FIR and the reverse 0. however there is no coefficeint and my filter just passes the input data with no filtering.

can anyone help please(as im new to labview im sure ive done something wrong)

thanks

[Jonah_TSE · Accepted solution]

Is the VI that you included the one you meant to upload? Currently you are setting the samples of a sine pattern to 0, and then multiplying by the reciprocal of 0, which will return NaN (not a number), so you won't get any meaningful output from this. If you mean to vary these numbers, then I'd recommend making them controls on your front panel (right clickon the number>>Change to Control)

At the moment you have also not wired anything into the coefficients input of the FIR filters. If you were previously opening the VI and changing the values within its front panel, these changes don't persist when you call the function from another VI. Right click on the "FIR Coefficients" input to the FIR Filter VIs, go to Create>>Constant and enter your coefficients into the array that comes up.

Regards,

Jonah