The FANUC A20B-8102-0420 is a Fast Ethernet Board B used as an optional network communication board in compatible FANUC CNC and motion-control systems.

FANUC documentation identifies A20B-8102-0420 as the printed-circuit-board drawing number for the Fast Ethernet Board B, an option board designed to provide Ethernet communication capabilities within supported CNC configurations.

Depending on the installed CNC software options and parameter configuration, the board can support applicable Ethernet-based functions such as CNC data communication, file transfer, remote diagnostic communication, FOCAS2/Ethernet, DNS/DHCP, and selected industrial-network functions. Not every communication function is available in every control configuration.

FANUC lists the board for selected Series 30i/31i/32i/35i-B, B Plus, Power Motion i-A, Series 0i-F, and 0i-F Plus systems. Exact compatibility depends on the CNC model, system software version, installed options, and network configuration.

The A20B-8102-0420 is suitable for replacement when a confirmed Ethernet-board fault causes network initialization failures, lost CNC communication, intermittent data transfer, abnormal Ethernet status indications, or failure to connect with the configured network device.

• Ethernet communication functions tested before shipment
  
• In stock and prepared for prompt dispatch
  
• Worldwide DHL, UPS, and FedEx shipping

Product Details

• Brand: FANUC
• Part Number: A20B-8102-0420
• Alternative Format: A20B81020420
• Official Description: Fast Ethernet Board B
• Type: Ethernet Interface PCB / Network Communication Board
• Product Series: A20B-8102
• Hardware Type: CNC Optional Communication Board
• Application: FANUC CNC and Motion-Control Systems
• Function: Ethernet communication and CNC network connectivity
• Category: FANUC Communication PCB / CNC Ethernet Board

Referenced Control Systems

FANUC documentation lists the following applicable system families for the A20B-8102-0420 Fast Ethernet Board B:

• FANUC Series 30i/31i/32i/35i-Model B
• FANUC Series 30i/31i/32i/35i-Model B Plus
• FANUC Power Motion i-Model A
• FANUC Series 0i-Model F
• FANUC Series 0i-Model F Plus

These references indicate supported product families, not universal interchangeability across every controller in those families.

Related Ordering Specifications

The same A20B-8102-0420 PCB is referenced under different FANUC option-ordering specifications according to the control family:

• A02B-0323-J167: Series 30i/31i/32i/35i-B and Power Motion i-A
• A02B-0353-J167: Series 30i/31i/32i/35i-B Plus
• A02B-0338-J167: Series 0i-F
• A02B-0348-J167: Series 0i-F Plus

Compatibility Note

Before ordering the A20B-8102-0420, please verify:

• Complete FANUC CNC model and system specification
• Full PCB number and revision marking
• Required Ethernet hardware option
• CNC system and Ethernet software versions
• Installed communication-function options
• Original connector and faceplate configuration
• CNC network parameters and IP settings

The Fast Ethernet Board B requires compatible system software and correct option and parameter configuration. A board replacement alone may not activate a communication function that is not installed or enabled in the CNC system.

Common Use Cases

• FANUC Fast Ethernet Board B replacement
• CNC Ethernet communication troubleshooting
• Repair of unstable or interrupted network connections
• Replacement of a damaged CNC network interface PCB
• Diagnosis of abnormal Ethernet status or error indications
• Restoration of CNC data-transfer and communication functions
• Preparation of a tested spare communication board

Sales & Support

Each A20B-8102-0420 Ethernet board is inspected and tested under applicable conditions before delivery.

Worldwide shipping is available through DHL, UPS, FedEx, and other express carriers. REACO CNC provides PCB repair service, warranty coverage, testing-video support, and  technical assistance for FANUC CNC Ethernet boards and communication components.