FANUC Alarm PRIO-063 — WARN Bad I/O asg: rack … slot …
Manufacturer wording — WARN Bad I/O asg: rack %d slot %d
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC PRIO-063 (“WARN Bad I/O asg: rack … slot …”): One or more assignments to the process I/O board or module at the specified rack and slot was invalid when the controller was turned on. First check: Check the connections and power to the board or rack and that the module(s) are firmly installed.
Updated 2026-09-17 · LogrobotLM reference
Description
One or more assignments to the process I/O board or module at the specified rack and slot was invalid when the controller was turned on.
Remedy
Check the connections and power to the board or rack and that the module(s) are firmly installed. If the board or module has been permanently removed, moved to a different Model A slot or had its switch settings changed (model B), use the CONFIG option on the Digital I/O menu to delete or update the assignment(s).
Related codes
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 →