Fanuc A20B-9001-0480 sub I/O board. You will find this 52/40 sink type sub I/O board piggy backs on larger 16/18 main plugin I/O boards. This particular board extends I/O functionality plugging into system I/O cards such as A16B22020960 extending IO from 104/80 to 156/120 DI/DO.
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.