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FANUC Alarm SRVO-270 — SERVO EXEMG1 status abnormal

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

FANUC SRVO-270 (“SERVO EXEMG1 status abnormal”): The EXEMG2 status is still ON when the EXEMG signal is asserted. First check: Repair the EXEMG2 circuit.

Updated 2026-10-22 · LogrobotLM reference

Description

The EXEMG2 status is still ON when the EXEMG signal is asserted.

Remedy

Repair the EXEMG2 circuit.

Field diagnosis

Chain alarm on channel 1 of the external emergency stop: EES wiring inconsistent between channels.

What to check

  • Check the circuit on both EES inputs and the simultaneity.
  • After correction: emergency stop pressed/released, RES_1CH, RESET.
  • Note: Often an external button with only one of its contacts wired.
  • Diagnostic sequence “Dual emergency stop circuit”: A chain code (230/231, 266…275, 370…373) means that only one of the two redundant channels has switched: the robot still runs, but safety is no longer redundant. Identify the channel from the number (1 = +24 V, 2 = 0 V), reproduce a firm operation of the device concerned, wait for the chain-repaired message, then RES_1CH and RESET. Never reset without having found the cause.

Related codes

SRVO-271SERVO EXEMG2 status abnormalSRVO-007SERVO External emergency stopsSRVO-204SYSTEM External(SVEMG abnormal) E-stopSRVO-268SERVO SVOFF1 status abnormalSRVO-269SERVO SVOFF2 status abnormalSRVO-272SERVO SVDISC1 status abnormal

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 →