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FANUC Controller
Servo/Axis · Intermediate · 5-30 minutes
Fanuc 471 - Fssb axis setting error
Alarm 471 indicates a mismatch or configuration error between the FSSB axis assignments in the CNC parameters and the physical servo amplifier setup on the serial bus. This typically occurs when the number of axes, axis addresses, or amplifier types defined in parameters do not match what is detected on the FSSB communication line.
471
Fanuc 471 - Fssb axis setting error
FSSB AXIS SETTING ERROR
An FSSB (Fanuc Serial Servo Bus) error has been detected related to fssb axis setting error. The serial bus communication between the CNC and servo amplifiers is affected.
Root Cause Summary
Alarm 471 indicates a mismatch or configuration error between the FSSB axis assignments in the CNC parameters and the physical servo amplifier setup on the serial bus. This typically occurs when the number of axes, axis addresses, or amplifier types defined in parameters do not match what is detected on the FSSB communication line.
Safety
- Verify corrected program or parameters before resuming machining
Causes and Fixes
- 1
Access parameter 8000 and verify the number of controlled axes matches your machine configuration.
- 2
Check parameter 8020 (FSSB axis assignment) for each axis to ensure correct axis numbers are assigned sequentially without gaps or duplicates.
Write down current settings before making changes for recovery purposes.
- 3
Verify parameter 8025 (amplifier type setting) matches the physical amplifier models installed on each axis position.
- 4
Power cycle the complete system after parameter corrections and verify all axes are recognized during boot sequence.
Ensure machine is in a safe state and emergency stop is accessible before power cycling.
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