What causes Okuma OSP alarm 2690?

Rotary encoder 1 itself defective. Motor encoder faulty. Encoder link cable damaged or connector loose/contaminated. Control base of the inverter unit defective.

How do I fix Okuma OSP alarm 2690?

1. Read the code number shown with the alarm: code XXYYZZZZ = Same code breakdown as alarm 0865 'MCS Encoder initialize failed', indicating the initialization stage that failed 2. Note the axis named in the object and the displayed code — the code format matches alarm 0865 'MCS Encoder initialize failed' and points to the failing stage of initialization. 3. Inspect the encoder link cable and connectors on that axis: reseat both ends, check for crushed cable, oil ingress, or bent pins — this is the most common and cheapest fix. 4. Swap the encoder link cable with a known-good one (or another axis if identical) and see whether the alarm follows the cable. 5. If the cable checks out, replace rotary encoder 1 / the motor encoder on the named axis and retry power-up initialization. 6. If the alarm persists with a known-good encoder and cable, replace the control base of the inverter unit for that axis. 7. If it still returns after these checks, record the alarm number, code, and object and contact Okuma service.

Okuma OSP codes

axismd.ai

Okuma OSP Controller

Servo/Axis · Intermediate

Alarm 2690

Okuma OSP Alarm B 2690 - MCS Rotary encoder 1 initialization failure

The control could not complete the initialization sequence for rotary encoder 1 on the axis named in the object. Because position feedback cannot be established, the axis cannot be operated until the encoder, its cabling, or the inverter control base is repaired.

Okuma OSPServo/AxisIntermediate

2690

Okuma OSP Alarm B 2690 - MCS Rotary encoder 1 initialization failure

MCS Rotary encoder 1 initialization failure

Common Causes

Rotary encoder 1 itself defective
Motor encoder faulty
Encoder link cable damaged or connector loose/contaminated
Control base of the inverter unit defective

Troubleshooting Steps

1Read the code number shown with the alarm: code XXYYZZZZ = Same code breakdown as alarm 0865 'MCS Encoder initialize failed', indicating the initialization stage that failed
2Note the axis named in the object and the displayed code — the code format matches alarm 0865 'MCS Encoder initialize failed' and points to the failing stage of initialization.
3Inspect the encoder link cable and connectors on that axis: reseat both ends, check for crushed cable, oil ingress, or bent pins — this is the most common and cheapest fix.
4Swap the encoder link cable with a known-good one (or another axis if identical) and see whether the alarm follows the cable.
5If the cable checks out, replace rotary encoder 1 / the motor encoder on the named axis and retry power-up initialization.
6If the alarm persists with a known-good encoder and cable, replace the control base of the inverter unit for that axis.
7If it still returns after these checks, record the alarm number, code, and object and contact Okuma service.

Seeing Multiple Alarms?

Seeing another alarm with this one? Enter the code.

Get machine-aware diagnosis

AxisMD logs alarms against your actual machines, tracks patterns, and gives AI context your manual doesn't have.

Start free

Was this guide helpful?

Always verify with your machine manual or a certified technician before performing service procedures.