What causes FANUC alarm 5137?

FSSB parameter settings (Param 1023, 1905, 1910-1919) do not match the actual amplifier hardware connected on the fiber optic loop. A servo amplifier has been replaced with a different axis count or model type without updating the FSSB configuration. Fiber optic cable is damaged, disconnected, or connected in the wrong order causing the control to detect a different amplifier layout than expected. Control parameters were restored from a backup that does not match the current machine hardware configuration. An amplifier was added or removed from the FSSB loop without performing a new FSSB automatic setting.

How do I fix FANUC alarm 5137?

1. Go to the FSSB setting screen (System > FSSB) and compare the amplifiers detected on the Amplifier screen against what is physically connected. Look for any mismatches in axis count or amplifier type. 2. Check Param 1023 for each axis to confirm axis-to-amplifier assignments are correct and match the physical order of amplifiers on the fiber optic loop. 3. Inspect all fiber optic cables on the FSSB loop from the control to each amplifier and back. Reseat any loose connectors and replace any cracked or damaged cables. 4. If the hardware matches the intended configuration, try running FSSB automatic setting: go to the FSSB screen, select the Amplifier tab, and use the automatic initialization function to let the control re-detect and assign amplifiers. 5. After any FSSB re-initialization, power the machine completely off and back on to allow the new configuration to take effect, then verify no alarm returns. 6. If the alarm persists after re-initialization, compare current parameters against the machine builder backup and restore correct FSSB-related parameters (1905, 1910-1919) manually.

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FANUC Controller

Servo/Axis · Advanced · 45-120 minutes

Alarm 5137

Fanuc Alarm 5137 - FSSB: CONFIGURATION ERROR

Fanuc alarm 5137 FSSB CONFIGURATION ERROR occurs when the physical FSSB (Fiber Servo System Bus) hardware configuration does not match the servo amplifier parameters programmed in the CNC control. This mismatch is typically caused by incorrect axis parameter settings, amplifier type misidentification, wrong FSSB channel/address assignments, or replaced amplifiers without proper parameter updates.

FANUCServo/AxisAdvanced45-120 minutes

5137

Fanuc Alarm 5137 - FSSB: CONFIGURATION ERROR

FANUC ALARM 5137

Root Cause Summary

Fanuc alarm 5137 FSSB CONFIGURATION ERROR occurs when the physical FSSB (Fiber Servo System Bus) hardware configuration does not match the servo amplifier parameters programmed in the CNC control. This mismatch is typically caused by incorrect axis parameter settings, amplifier type misidentification, wrong FSSB channel/address assignments, or replaced amplifiers without proper parameter updates.

Causes and Fixes

1
Navigate to SYSTEM > PARAM and check parameters 8120-8139 for each axis. Parameter 8120 assigns axis 1, 8121 assigns axis 2, etc. Format is XXYY where XX=FSSB channel (01-04) and YY=axis address (01-08). Record all settings.
2
Power down CNC and check physical servo amplifier rotary switches or DIP switches. Each amplifier must have unique axis address matching parameter settings. Verify FSSB optical cable connection sequence matches channel assignments.
Power off both CNC and amplifier power supply before accessing amplifier switches. High voltage present.
3
Navigate to DIAGNOSIS > SERVO > FSSB (screens vary: may be under DIAGNOSIS screen #380-#389 or dedicated FSSB page). Verify detected amplifiers match parameter configuration. Check for missing axes or duplicate addresses.
4
Correct any mismatches by either adjusting amplifier address switches to match parameters, or updating parameters 8120-8139 to match physical hardware. Power cycle after changes and verify alarm clears.

DIY Feasiblehigh confidence

Call a technician if:

·Multiple amplifier failures detected
·FSSB auto-setup fails repeatedly
·Parameter backup/restore required

Prevention

Regular parameter backup
Secure FSSB cable connections during maintenance
Document amplifier address settings
Use proper FSSB termination

Common Mistakes

Forgetting to power cycle after parameter changes
Incorrect FSSB address sequence
Missing termination resistor
Using non-Fanuc FSSB cables

Related Alarms

5136 5138 5140 5141

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