Read ampere from a spindle with frequency

I have made a small card that read Ampere from my spindle and converts it to a frequency, i wan to read this frequency and show it on axis interface, like my spindle Ampere Meter.

Right now what i have done is connecting the pin where i get the frequency to an encoder phase A in counter mode, i now check the velocity of this encoder to see an approximate frequency.

This way i can see that everything is working, but i want to display better, and i want to be able to display in ampere, right now when i'm at 3 Amps and i see 10000 in encoder velocity.

any suggestion

Thanks, i've done it, works like a charm