LogrobotLM

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FANUC Alarm SRVO-455 — CPU watch dog

Error
Hardware
servo amplifier
Controllers
R-30iB (this generation only)
FANUC class
SERVO (default, not tabulated in the sources)
Hardware family
FANUC servo amplifier alarms: power, DC link, currents and IPM

FANUC SRVO-455 (“CPU watch dog”): The amplifier processor has stopped responding to its watchdog.

Updated 2026-10-22 · LogrobotLM reference

What it means

The amplifier processor has stopped responding to its watchdog.

What to check

  • Replace the amplifier.
  • Note: R-30iB code only.

Related codes

SRVO-454CPU BUS failureSRVO-451Internal S-BUS failSRVO-453Low volt driverSRVO-456Ground faultSRVO-459Excess regeneration2…

Indicative field information — the robot manufacturer's manual and safety procedures always prevail. Never bypass a safety device; apply lockout/tagout (LOTO) before any physical intervention. How this reference is built →