Fanuc A20B-8001-0420 sub I/O board. You will find this 52/40 sub I/O board piggy backs on larger 16/18 main plugin I/O boards. This particular board plugs into FTS I/O board A16B-2202-0960.
DNC currently have stock of this DI 52 and DO 40 I/O pcb. Contact us for prices and more details on this add I/O sub pcb.