7i76e - Spindle FWD/ENA ok, but no speed output

Well, my tests yesterday showed tiny problems with the frequency. If I set the output to zero/stop, the voltage at TB4, Pin 2 Spindle Out is 0,045V and the VFD shows 1,56 Hz. The Input voltage at Pin 3 is 9,99V.
Next inaccuracy is frequency setting at S3000 ->50Hz, output is at 2,3V and 45,8 Hz instead of 2,5V and 50Hz.

What can I do to put Pin 2 to zero Volt? Is this a problem of the 7i76e/Lcnc or do I have to calibrate my VFD?

Thanks for your help, again!
Hanno

An analog circuit with a 0V negative reference cannot swing all the way down to 0V
so the 45 mV 0 level is expected. Also linearity of the output should be better than 1%.

Normally the 0 level is not too important as the spindle enable should be false so the
drive is disabled at that point. If you want to improve the accuracy, you can use the
lincurve component, but note that spindle speed accuracy is not terribly important
for most applications.

Thanks! I just want to prevent current through the spindle coils. I found parameters in the VFD to suppress low frequencies, so I think its solved. Thanks for your hints!
Hanno