Fanuc alarm 950: PMC SYSTEM ALARM (PCxxx YYYYYYYYYYYY)
system alarm · Fanuc 0i-D
What it means
Internal error detected in the PMC (ladder processor) - displayed code identifies faulting area/module
Likely causes
- PMC control module failure on main board
- faulty I/O Unit connected via I/O Link
- corrupt PMC ladder/ROM
Triage note: Decode the PCxxx sub-code: faults pointing at I/O Link slaves mean replace the I/O unit/cable, otherwise the main board
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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A20B-8200-0740
Main CPU Board (0i-D, PMC integrated) · Primary suspect
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A03B-0815-C001
I/O Unit (IO Link, e.g. OE/OC model) · Common cause
Need the part urgently?
Send us alarm 950 with your machine details — typical RFQ turnaround is 24–48h.