LogrobotLM

LogrobotLM — AI fault diagnosis for ABB · KUKA · FANUC robots. It reads your robot backup in your browser (never uploaded) and pinpoints the fault. Try it free →

FANUC Alarm FRCE-521 — AIT X direction fail (F:…)

Manufacturer wording — AIT X direction fail (F:%d^1)
The manual prints placeholders; your controller fills them in with the real group, axis or number.

FANUC FRCE-521 (“AIT X direction fail (F:…)”): Impedance parameters auto tuning in the X direction did not complete. First check: Correct the errors in the following order; then execute the impedance parameters auto tuning again.

Updated 2026-09-17 · LogrobotLM reference

Description

Impedance parameters auto tuning in the X direction did not complete.

Remedy

Correct the errors in the following order; then execute the impedance parameters auto tuning again. 1. Stop any vibration sources that are near the robot. 2. The desired force might be too small. Increase the desired force.

Related codes

FRCE-519AIT R direction unstable (F:…)FRCE-520AIT all switch OFF (F:…)FRCE-522AIT Y direction fail (F:…)FRCE-523AIT Z direction fail (F:…)

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 →