FANUC Alarm TAST-004 — STOP TAST IO start failed

FANUC TAST-004 (“STOP TAST IO start failed”): IOSETRTN error has occurred First check: Perform a cold start of controller

Updated 2026-09-17 · LogrobotLM reference

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 →