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FANUC Controller
Servo/Axis · Intermediate · 5-30 minutes
Fanuc 482 - Fssb gain error
Alarm 482 indicates a gain mismatch or configuration error in the FSSB communication system between the CNC and servo amplifier. This typically occurs when the servo amplifier's gain settings don't match the CNC parameters, after amplifier replacement, or when parameter corruption has occurred.
482
Fanuc 482 - Fssb gain error
FSSB GAIN ERROR
An FSSB (Fanuc Serial Servo Bus) error has been detected related to fssb gain error. The serial bus communication between the CNC and servo amplifiers is affected.
Root Cause Summary
Alarm 482 indicates a gain mismatch or configuration error in the FSSB communication system between the CNC and servo amplifier. This typically occurs when the servo amplifier's gain settings don't match the CNC parameters, after amplifier replacement, or when parameter corruption has occurred.
Safety
- Verify corrected program or parameters before resuming machining
Causes and Fixes
- 1
Power down the machine completely and verify which axis is affected by checking the alarm detail screen for the axis number.
- 2
Access servo parameters and compare parameter 2020-2027 (servo motor model) and 2041-2048 (current loop gain) against the actual motor and amplifier specifications on the affected axis.
- 3
If parameters are incorrect or suspicious, re-input correct servo parameters from machine documentation or use automatic parameter setting function (axis parameter setup wizard) if available.
Incorrect servo parameters can cause runaway conditions. Ensure all safety measures are active before testing.
- 4
Execute servo parameter initialization by cycling power, then perform a careful jog test at 5% rapid override with one hand on emergency stop.
Be prepared for unexpected axis movement during initial jog test.
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Always verify with your machine manual or a certified technician before performing service procedures.