FANUC Alarm SRVO-055 — SERVO FSSB com error 1
Error- Hardware
- FSSB link and axis control card
- Controllers
- R-J3iB / R-30iA / R-30iB
- FANUC class
- SERVO2
Manufacturer wording — SERVO FSSB com error 1 (G:%d A:%d)
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC SRVO-055 (“SERVO FSSB com error 1”): An FSSB communication error from SRVO to SLAVE occurred. First check: Check the FSSB hardware connection.
Updated 2026-10-22 · LogrobotLM reference
Description
An FSSB communication error from SRVO to SLAVE occurred.
Remedy
Check the FSSB hardware connection.
Field diagnosis
Communication error on the FSSB link in the main board to amplifier direction.
What to check
- Check the optical fiber between the axis control board and the amplifier (bending, dirty connector) and replace it if suspect; then axis control board, then amplifier.
- Auxiliary axes: see their own amplifier.
- Note: A fiber bent too tightly in the cabinet cable duct is enough; check the bend radius first.
Related codes
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 →