A20B-8100-0671 Fanuc PCB Board A20B81000671 A2OB-8IOO-O67I

FANUC A20B-8100-0671 FL-NET Ethernet Communication PCB

Overview

The A20B-8100-0671 is an FL-NET Ethernet communication PCB in the A20B-8100 family. It is identified as an FL-NET board, an Ethernet card, and an FL-NET interface board, placing it in the communication layer of the control rather than in the servo, power, or display section.

The model is also associated with standalone i-series robot controls, including one-slot configurations where network-level communication is part of the installed controller structure.

From a maintenance perspective, this board is used where the controller already depends on FL-NET fieldbus connectivity between machines, cells, or robot systems.

That makes exact board-role matching especially important: a communication PCB must preserve the same protocol path, connector role, and installed control architecture already present in the machine.

The board is commonly handled in replacement, refurbishment, and tested-stock channels, which is typical for installed-base communication hardware that remains in service long after the original system build.

Technical Data

Applications

This board is suitable for installed FANUC CNC and robot systems that already use FL-NET communication in the A20B-8100-0671 board position.

It is especially relevant in production-cell communication layouts where machines or robots exchange data through fieldbus-linked control hardware. 

It also fits service situations where the original network board has failed but the rest of the controller hardware remains in place.

Replacement Guidance

Before ordering, confirm the installed board code directly on the hardware and verify that the existing controller uses FL-NET rather than another network standard such as DeviceNet, PROFIBUS, or standard Ethernet-only add-on hardware.

It is also important to confirm the controller form factor and slot arrangement, especially on standalone i-series control configurations.

Matching the exact board family is the safest way to keep the existing network structure unchanged.

FAQ

Q1: What kind of board is A20B-8100-0671?
It is an FL-NET Ethernet communication PCB. In installed systems, its role is to provide fieldbus-level communication for CNC or robot control hardware rather than to handle display logic, internal power conversion, or servo amplifier control.

That makes it a network-side board with a clearly defined communication function.

Q2: Why is the FL-NET description so important?
Because the communication protocol is one of the board’s defining characteristics.

A controller already built around FL-NET should keep the same communication-board type to preserve the original network architecture, message path, and machine-to-machine data exchange structure. 

Swapping to a different communication board can change the interface role even if the board family looks similar.

Q3: Is this a robot board or a CNC board?
It can appear in both control environments, but the most specific fit described for this model is within i-series robot controls and CNC communication contexts.

The common thread is not the machine category itself, but the FL-NET communication role inside the installed control structure.

That is the part that should match during replacement.

Q4: Is this a main board?
No. This model belongs to the communication-board layer, not the system motherboard.

It supports network connectivity and data exchange inside the controller, while the main board remains responsible for the broader control platform and processor-side functions.

Q5: What should be checked before buying?
Check the installed part number, confirm the controller uses FL-NET, verify the slot position, and make sure the existing board is really A20B-8100-0671.

On older communication boards, reading the actual board label in the cabinet is more reliable than relying only on a machine parts list or memory.