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Okuma OSP Controller
Servo/Axis · Intermediate
Okuma OSP Alarm D 4685 - MCS Rotary encoder 4 initialization failure
The MCS could not finish initialization of rotary encoder 4 (HEIDENHAIN) for the axis named in the object field. The encoder did not complete its power-up handshake, so position feedback from that encoder is unavailable.
4685
Okuma OSP Alarm D 4685 - MCS Rotary encoder 4 initialization failure
MCS Rotary encoder 4 initialization failure
The MCS could not finish initialization of rotary encoder 4 (HEIDENHAIN) for the axis named in the object field. The encoder did not complete its power-up handshake, so position feedback from that encoder is unavailable.
Common Causes
- Failed rotary encoder 4 (HEIDENHAIN) unit
- Encoder cable or connector problem between the encoder and the MCS
- Encoder supply or signal line fault preventing initialization
Troubleshooting Steps
- 1Note which axis is named in the object field, then power down and lock out before touching encoder wiring.
- 2Inspect the connector at rotary encoder 4 (HEIDENHAIN) for that axis: reseat it, check for bent pins, coolant ingress, or cable damage in the drag chain.
- 3Swap the encoder cable with a known-good one if available, or measure continuity of the signal and supply lines back to the MCS.
- 4Power up and watch whether initialization completes; if the same axis fails again with good cabling, the corrective action is to change rotary encoder 4 (HEIDENHAIN) as the manual directs.
- 5If the alarm follows a cable swap to another axis, suspect the MCS input channel rather than the encoder.
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