Okuma Alarm-D 4181 MCS DIFF over

Okuma Alarm-D 4181 MCS DIFF over
Axis movement caused a large positioning error.
While the axis is in a target position or stopped, the target value and the calculated value are the same. With an axis movement command, the NC starts creating calculation values (RCON) until the target point is reached. At this time, the actual position follows the calculated value with a certain delay. This delay is called “following error” and calculated by ([calculation value] – [actual value]). If the “following error” exceeds the allowable limit, the above alarm occurs.

Axis name or none (spindle)


Absolute value of following error [pr/65536]
pr = One turn of position encoder

Probable Faulty Locations
– Overload due to faulty ball screw or bearing
– Motor
– Inverter unit
– Servo data file

Okuma Alarm-D 4181 MCS DIFF over