FANUC A20B-9001-0480 is a 52-input/40-output sink-type Sub I/O expansion PCB for compatible FANUC Series 16/160 and 18/180 Model B CNC control configurations. It expands machine-side digital input and output capacity when installed with the specified main I/O card.

FANUC documentation identifies this add-on board for use with A16B-2200-0950 or A16B-2200-0955. It is not a standalone I/O controller, CPU board or power supply, and the board has no LED status display.

A20B-9001-0480 Product Information

52/40 Sub I/O Expansion Function

The A20B-9001-0480 adds 52 digital input points and 40 digital output points to a compatible sink-output I/O configuration. It exchanges machine status and command signals between the CNC/PMC and external devices. Signal addresses, connector assignments and machine functions depend on the machine builder's wiring and PMC ladder.

Main I/O Card and Revision Compatibility

Confirm the complete A20B-9001-0480 marking and revision, such as /05B when shown on the original board. A16B-2200-0950 is a 104-input/80-output sink-type card with high-speed skip, while A16B-2200-0955 is the corresponding version without high-speed skip. Do not substitute A20B-8001-0150 solely because it is also a 52/40 expansion board; that model is documented for different source-output I/O cards.

Testing and Installation Notes

REACO CNC checks the model marking, PCB condition, connectors, input/output circuits and operation with a compatible assembly as applicable. Before replacement, back up CNC parameters and PMC data and label all connections. Isolate machine power and use anti-static protection during installation.

Related resources: FANUC CNC and robot parts and FANUC CNC board repair service.