Hello all, I just converted from m3 to m4 with a new hicon 7866 controller.
I'm running steppers , with no feed back to the hicon,
when I'm running my feed rate display keeps changing...

?
if  I  command a G01 Y60 F125 the feed rate display will bounce between something 
like 124.53 to a 125.8  this seems strange to me,  why would it be changing?  also the movement is jerky I can feel it is not smooth. 
Can any one explain this to me? 
this evens happens even  if I use  a G61 .
Thank you
Jerry