Compatibility

• CNC Series: FANUC 16i‑B, 18i‑B, 21i‑B (i‑B series controls)

• Robotics: FANUC LR‑Mate and other robot mainboards

• Slot: Installs on CNC main CPU board (A20B‑8100 series)

Key Specifications

• FROM (Flash ROM): 32 MB (stores system software, CNC programs, parameters)

• SRAM (Static RAM): 1 MB (volatile memory for active data, tool offsets, macros)

• Interface: FANUC proprietary DIMM edge connector

• Power: 3.3 V DC from main board

• Operating Temperature: 0 °C to +55 °C

• Humidity: 5%–95% RH (non‑condensing)

Main Functions

• System Storage: Holds CNC OS, PMC programs, and user‑defined cycles (FROM)

• Active Memory: Runtime data, axis positions, and temporary values (SRAM)

• Data Retention: SRAM backed by onboard battery (prevents data loss on power‑off)

• Firmware Updates: CNC system software loaded via this module

Common Sub‑type

• A20B-3900-0163/04A: Standard version for 16i‑B/18i‑B/21i‑B systems

Installation & Handling

• ESD Protection: Use anti‑static wrist strap (static sensitive)

• Power Off: Disconnect CNC power before insertion/removal

• Orientation: Align notch on card with slot key (do not force)

• Battery Care: Replace backup battery every 2–3 years to protect SRAM data

Troubleshooting

• Boot Errors: Check seating, battery voltage, or replace module

• Data Corruption: Verify battery health; restore parameters/programs

• System Crash: Ensure correct module type (match CNC series)