Bessel filtering?

[Graziano]

I want to get IIR bessel filter a and b coefficients, but I get all zeros as b. I used
Bessel_CascadeCoef(sampling_freq,lower_cutoff, upper_cutoff, filterInfo );
CascadeToDirectCoef (filterInfo,a,ORDER+1,b,ORDER+1);
with all defined variables.
The old style function does the same (Bessel_coef()).

[AlessioD]

Hello,

I was trying to reproduce the problem you are talking about but was not able to.
I am attaching below a small piece of code that I just tested on my CVI 7.1 and it returns meaningful values for the B coefficients.
Let me know how this works for you.

Regards,

AlessioD
National Instruments