FANUC Alarm CPMO-031 — JBF Len <= 0
Manufacturer wording — JBF Len <= 0 (G: %d^2)
The manual prints placeholders; your controller fills them in with the real group, axis or number.
FANUC CPMO-031 (“JBF Len <= 0”): An Internal INTR error has occurred. First check: The system might have been corrupted.
Updated 2026-09-17 · LogrobotLM reference
Description
An Internal INTR error has occurred. This class of error should not be encountered during normal operation.
Remedy
The system might have been corrupted. This might have been caused by any of a number of reasons including: Incorrect loading and setup loading incompatible options, mixing software version when adding options and other memory corruption problems. The following is a list of possible remedies:
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 →