Digital filter design ouptut scale in FXP mode

[MatGG]

Hi everyone,

I would like to make a LP filter on a AquadB signal I have from an interferometer, everything being embedded on a FPGA on a CRIO board 9237.

I get the A and B signal OK, and pass them to a loop where my filter is as 32 signed integers. I would like to have the output of my filter being more precised. therefore, I convert my signed integers to 32,24 FXP before entering my filter. I would like the ouptput of my filter to be 32,24 FXP values also before going up to my host.

Whatever I try in the step by step design filter vi (see picture attached), my output is between -1 and 1, instead of being between +/- 8.366 millions as mentionned in the help of the filter (see picture).

You'll find attached a picture of the config I choose in the step by step design, and my FPGA code.

Any help is welcome!!!

Regards,

Matthieu

[Jun']

Hi MatGG,

Would you mind sending your code instead of the picture?

Why is there a 0 conntected to your "convert into fxp" function?

Thanks

Junior