749
Serial Communication Error during Activation
Fanuc · AC Spindle Motor αi-βi Series Parameters
What does 749 mean?
A serial communication error occurred while the Series 16i system was being activated after power-on. This indicates a problem in the communication link to the spindle amplifier, preventing normal startup.
Repair Steps
Verified technical data. Last updated: March 2026
Source: Fanuc AC Spindle Motor αi-βi Series Parameters