Okuma Alarm-C 3688 MCS Rotary encoder 3 error

Okuma Alarm-C 3688 MCS Rotary encoder 3 error
Illegal data was detected in Rotary encoder 3(HEIDENHAIN).

Object
Axis

Character-string
None

Probable Faulty Locations
Rotary encoder 3(HEIDENHAIN).

Corrective Action
Change Rotary encoder 3(HEIDENHAIN).