FANUC Alarm CPMO-063 — MAINCHN is NULL

Manufacturer wording — MAINCHN is NULL (G: %d^2)
The manual prints placeholders; your controller fills them in with the real group, axis or number.

FANUC CPMO-063 (“MAINCHN is NULL”): Internal Error: Main Channel is NULL First check: Perform a Cold start:

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 →