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FANUC Alarm LNTK-027 — STOP Invalid data on LNTK stack

FANUC LNTK-027 (“STOP Invalid data on LNTK stack”): Invalid data was found on the tracking stack. First check: Perform a COLD start of the system.

Updated 2026-09-17 · LogrobotLM reference

Description

Invalid data was found on the tracking stack.

Remedy

Perform a COLD start of the system. (Cycle power.) Notify FANUC Robotics if problem persists.

Related codes

LNTK-025STOP Illegal encoder multiplierLNTK-026STOP Encoder not enabledLNTK-028STOP LNTK stack underflowLNTK-029STOP LNTK stack overflow

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 →