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FANUC Alarm SRVO-205 — SYSTEM Fence open(SVEMG abnormal)

Error
Hardware
emergency stop and dual safety chains
Controllers
R-J3iB / R-30iA / R-30iB
FANUC class
SYSTEM
Hardware family
FANUC emergency stop, pendant and dual safety chain alarms

FANUC SRVO-205 (“SYSTEM Fence open(SVEMG abnormal)”): The fence circuit is open and mis-wiring on SVEMG is detected. First check: Power off. Correct the wiring on SVEMG.

Updated 2026-10-22 · LogrobotLM reference

Description

The fence circuit is open and mis-wiring on SVEMG is detected.

Remedy

Power off. Correct the wiring on SVEMG. Close the fence circuit and then press RESET. Refer to the maintenance manual for details.

Field diagnosis

The fence circuit was opened without the emergency stop line being cut: one of the two EAS channels does not follow the other.

What to check

  • Check the switches and cables of both EAS channels; replace any suspect cable.
  • Otherwise, the emergency stop board is suspect (full backup before replacement).
  • A power cycle is required to clear the code.
  • Note: Doors with a single contact wired to both channels in parallel are the leading cause.

Related codes

SRVO-004SERVO Fence openSRVO-266SERVO FENCE1 status abnormalSRVO-267SERVO FENCE2 status abnormalSRVO-230SERVO Chain 1 (+24v) abnormalSRVO-203SVON input(SVEMG abnormal)SRVO-204SYSTEM External(SVEMG abnormal) E-stop

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 →