User: Our CNC milling machine is using GSK980MDa control system, positioning the tool
to the center of the workpiece, run G81 drilling cycle, the tool could not go back to
the original Z position, then the CNC alarms for "Z axis not ready", and it alarms only
when the speed of G00 is 100%, no alarm when it is 50%.

CNCmakers Support: This could be the vibration caused the short open of the limit switch.