What causes Okuma OSP alarm 0875?

Loose or damaged servo link cable or connector between units. Failed inverter unit control board. Failed FCP board in the NC.

How do I fix Okuma OSP alarm 0875?

1. Read the code number shown with the alarm: code XXXX=0 = Link disconnected immediately in front of the problem unit; code XXXX=8000 = Link disconnected somewhere before (upstream of) the problem unit; code YYYY = Servo link error status at the moment the error was detected 2. Read the code on screen: XXXX=0 means the link broke right in front of the problem unit; XXXX=8000 means the break is upstream of it, so start checking at the unit before the one named in the object. 3. Power down and lock out the machine, then reseat and inspect the servo link cables and connectors at the named axis/spindle unit and the preceding unit; look for bent pins, oil contamination, or chafed cable. 4. Check the link status LEDs on the inverter units to find the last unit still communicating; the break is between it and the next unit. 5. Swap or substitute the suspect link cable with a known-good one before condemning hardware. 6. If cabling checks out, suspect the inverter unit control board, then the FCP board; record the alarm number, code and object and contact Okuma service for board replacement.

Okuma OSP codes

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Okuma OSP Controller

Servo/Axis · Intermediate

Alarm 0875

Okuma OSP Alarm P 0875 - MCS Servo link disconnection

The NC lost communication over the MCS servo link, so the affected servo unit can no longer receive commands. The code identifies where along the link the break occurred and the link error status at detection.

Okuma OSPServo/AxisIntermediate

0875

Okuma OSP Alarm P 0875 - MCS Servo link disconnection

MCS Servo link disconnection

Common Causes

Loose or damaged servo link cable or connector between units
Failed inverter unit control board
Failed FCP board in the NC

Troubleshooting Steps

1Read the code number shown with the alarm: code XXXX=0 = Link disconnected immediately in front of the problem unit; code XXXX=8000 = Link disconnected somewhere before (upstream of) the problem unit; code YYYY = Servo link error status at the moment the error was detected
2Read the code on screen: XXXX=0 means the link broke right in front of the problem unit; XXXX=8000 means the break is upstream of it, so start checking at the unit before the one named in the object.
3Power down and lock out the machine, then reseat and inspect the servo link cables and connectors at the named axis/spindle unit and the preceding unit; look for bent pins, oil contamination, or chafed cable.
4Check the link status LEDs on the inverter units to find the last unit still communicating; the break is between it and the next unit.
5Swap or substitute the suspect link cable with a known-good one before condemning hardware.
6If cabling checks out, suspect the inverter unit control board, then the FCP board; record the alarm number, code and object and contact Okuma service for board replacement.

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