On the Fanuc control, check Diagnostic (DGN) 200 and 204 . DGN 200 #4 (HCA): Indicates an abnormal current alarm. DGN 200 #5 (OVC): Indicates an overcurrent alarm.
In the context of this essay, the "n-th axis" is the Z-axis. This alarm indicates that the digital servo system has detected a discrepancy between the command sent by the CNC control and the feedback received from the servo motor. The control system essentially "lost track" of where the Z-axis is physically located. Because the Z-axis typically controls the vertical movement of the spindle or the tool, a loss of position detection is treated as a critical safety fault, immediately engaging the emergency stop to prevent the tool from crashing into the table or the workpiece.
To minimize the likelihood of future FANUC 414 servo alarms related to the Z-axis detect error: