Compatibility

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

• Installation: Plugs into dedicated memory slot on main CPU board (A20B‑8100 series)

Key Specifications

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

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

• Interface: Proprietary FANUC 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 Firmware Storage: Holds CNC OS and PMC logic (FROM)

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

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

• Software Updates: CNC system software loaded via this module

Features

• R301A Design: Updated revision for improved reliability

• Industrial Grade: Shock/vibration resistant for factory environments

• Compact: Single‑board design for tight CNC cabinet spaces

Installation & Handling

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

• Power Off: Disconnect CNC power and wait 5 minutes before removal/installation

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

• Battery Maintenance: Replace backup battery every 2–3 years

Troubleshooting

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

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

• System Errors: Confirm correct module type (match i‑B series)

Comparison with A20B-3900-0163

• Both: 32 MB FROM / 1 MB SRAM, same form factor & compatibility

• 0223: R301A revision (newer, more robust)

• 0163: Older revision (common, fully compatible)