Fanuc 366 Alarm May 2026

The Fanuc 366 Alarm, typically displayed as SV0366: n AXIS: PULSE MISS (INT), indicates a communication or detection error within the built-in pulse coder of the specified axis. This occurs when the internal feedback system fails to track the expected number of pulses, suggesting a physical or electrical interruption in the encoder signal.  Top Troubleshooting Steps 

Result: Alarm 366. Correct single-line: IF [#1 EQ 5] THEN #2 = 10 (THEN is optional on some controls but required on others; safer to use it). For multi-line, use IF [#1 EQ 5] THEN … ENDIF. fanuc 366 alarm

Common Causes & Specific Scenarios

This alarm is almost always triggered by one of the following syntax violations: The Fanuc 366 Alarm , typically displayed as

Manual Rotation Test: Remove the servo motor and rotate the shaft manually while watching the position screen. If the numbers do not change, the pulse coder or cable is definitely not sending signals. 2. Inspect the Feedback Cable The cable is often the weakest link in the system. Correct single-line: IF [#1 EQ 5] THEN #2

: In many cases, the "pulse miss" isn't a broken wire but physical interference. If a tool is unbalanced or motor bearings are worn, excessive vibration can shake the encoder's internal optics. This causes the read head to momentarily miss lines on the internal grating, triggering the alarm. A simple check is to feel the motor housing for unusual vibration while it's running. The Weakened Signal