From Friday, April 19th (11:00 PM CDT) through Saturday, April 20th (2:00 PM CDT), 2024, ni.com will undergo system upgrades that may result in temporary service interruption.
We appreciate your patience as we improve our online experience.
Have you seen the IIR Filter documentation from the LabVIEW help? It explains some theory behind our IIR filter VIs. As for the internal logic behind the function, the VI just uses a Call Library Function on one of our LabVIEW analysis DLLs to call into the specific function corresponding to the filter you have selected.