I have set up a basic screen for some experimenting,  I am using standard X,Y,Z Dros  for the stepper motors and have added encoders to the axis,s for a comparison read out, I am using OEM DRO codes of 170,171,172 and have added buttons to zero encoders and asigned Button codes 133,134,135, when I press one of these buttons to zero a encoder it will not totally zero the encoder, I also added DRO to show differences between stepper DRO and encoder DRO using DRO codes 127,128,129 these seem to be working, does anyone have a clue to what I am missing? also in Dro code 173 would allow me to add a 4 encoder DRO but in button codes there is only button codes for XYZ ( three axis ) how would I zero the 4th encoder?.  John