Simulink eQEP block for frequency calculation with F28069 MCU

Hi,

I'm using eQEP block to read the frequency input of a signal and having some difficulties. Here are the Simulink settings for eQEP block:

I'm reading Position Counter (QPOSCNT) and here is the logic to calculate the frequency:

It reads the frequency of input signal correctly when it's above ~200Hz and for any value smaller than 200Hz the reading is not accurate. For values below 20Hz it's totally off. Any help would be appreciated.

Thanks,

--Kash