Fanuc alarm SP1978: SERIAL SPINDLE COMMUNICATION ERROR
spindle alarm (serial spindle interface, CNC side) · Fanuc 0i-D
What it means
A timeout was detected in communication with the serial spindle amplifier; an expected response did not arrive within the allotted window. The amplifier may have stopped responding entirely, or the link quality degraded enough that frames were lost repeatedly.
Likely causes
- Spindle amplifier power interrupted or amplifier latched off
- Intermittent serial interface cable or connector contact
- Failed communication IC on the amplifier or CNC side
Need the part urgently?
Send us alarm SP1978 with your machine details — typical RFQ turnaround is 24–48h.