LogrobotLM

LogrobotLM — AI fault diagnosis for ABB · KUKA · FANUC robots. It reads your robot backup in your browser (never uploaded) and pinpoints the fault. Try it free →

FANUC Alarm SRVO-056 — SERVO FSSB com error 2

Error
Hardware
FSSB link and axis control card
Controllers
R-J3iB / R-30iA / R-30iB
FANUC class
SERVO2
Hardware family
FANUC FSSB link, axis control card and amplifier initialisation alarms

Manufacturer wording — SERVO FSSB com error 2 (G:%d A:%d)
The manual prints placeholders; your controller fills them in with the real group, axis or number.

FANUC SRVO-056 (“SERVO FSSB com error 2”): An FSSB communication error from SLAVE to SRVO occurred. First check: Check the FSSB hardware connection.

Updated 2026-10-22 · LogrobotLM reference

Description

An FSSB communication error from SLAVE to SRVO occurred.

Remedy

Check the FSSB hardware connection.

Field diagnosis

FSSB communication error in the amplifier to main board direction.

What to check

  • Same procedure as SRVO-055: fiber, axis control board, amplifier.
  • Note: 055 and 056 together: the fiber; only one of them: rather the transmitter for that direction.

Related codes

SRVO-055SERVO FSSB com error 1SRVO-057SERVO FSSB disconnectSRVO-054SYSTEM DSM memory error (DSM:…)SRVO-058SYSTEM FSSB 1 init error

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 →