Okuma OSP codes
AxisMD

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Okuma OSP Controller

Servo/Axis · Intermediate

Alarm 1690

Okuma OSP Alarm A 1690 - MCS Rotary encoder 1 initialization failure

The MCS drive could not complete initialization of rotary encoder 1 on the axis named in the object field. Without a successful encoder initialization the axis position feedback is untrustworthy, so the control stops the axis.

Okuma OSPServo/AxisIntermediate

1690

Okuma OSP Alarm A 1690 - MCS Rotary encoder 1 initialization failure

MCS Rotary encoder 1 initialization failure

The MCS drive could not complete initialization of rotary encoder 1 on the axis named in the object field. Without a successful encoder initialization the axis position feedback is untrustworthy, so the control stops the axis.

Common Causes

  • Faulty rotary encoder 1
  • Faulty motor encoder
  • Damaged or loose encoder link cable or connector
  • Defective control base of the inverter unit

Troubleshooting Steps

  1. 1Read the code number shown with the alarm: code XXYYZZZZ = Decoded identically to alarm 0865 'MCS Encoder initialize failed'
  2. 2Note the axis named in the object field and record the XXYYZZZZ code; it decodes the same way as alarm 0865 'MCS Encoder initialize failed'.
  3. 3Power down and lock out the machine; inspect the encoder link cable and connectors at both the encoder and inverter ends for looseness, bent pins, or coolant ingress, then reseat them.
  4. 4Power up and retry; if the alarm returns, swap or replace rotary encoder 1 and check.
  5. 5If still failing, check/replace the motor encoder.
  6. 6Last, suspect the control base of the inverter unit — replace and check only after the cable and encoders are eliminated.
  7. 7If the alarm persists after these unit exchanges, record the alarm number, code and axis and contact Okuma service.

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