Fanuc alarm 970: NMI OCCURRED IN PMCLSI
PMC/I-O Link alarm · Fanuc Power Mate
What it means
A non-maskable interrupt originated in the PMC control LSI on the motherboard - with PMC-SA1 class interfaces this is an I/O RAM parity error inside the PMC's own control chip. The ladder processor is halted and the whole CNC stops because I/O handling cannot continue safely.
Likely causes
- Defective PMC control LSI / motherboard section
- I/O RAM parity upset from noise
- Motherboard ageing or thermal damage
Triage note: Companion code 971 covers NMIs from the serial link (SLC); 972 covers option boards.
Need the part urgently?
Send us alarm 970 with your machine details — typical RFQ turnaround is 24–48h.