Fanuc Axis card A20B-8200-0361 A2OB-82OO-O361 A20B82000361

A20B-8200-0361 | FANUC Series 0i-TC 2-Axis FSSB Servo + LCD Graphics Card — Dual-Function PCB / Two-Axis Lathe / 0i-C Platform

One Card, Two Critical Functions

The A20B-8200-0361 is a single PCB that performs two distinct and essential roles within the 0i-TC CNC lathe control unit:

FSSB Servo Controller (2 channels): The board generates the FSSB (Fibre Optic Servo Serial Bus) communication signals for the lathe's two servo axes — typically X (cross-slide) and Z (carriage). FSSB is FANUC's fibre-optic serial bus that carries position commands from the CNC to the servo amplifiers and returns encoder feedback to the CNC.

LCD Graphics Engine: The board simultaneously drives the CNC's LCD display — generating the video output signal that produces the operator interface display seen on the lathe's integrated screen. Alarm messages, programme content, position displays, and tool offset pages all originate from this graphics function.

Combining both functions on a single card is an architectural decision specific to the 0i-TC two-axis lathe configuration. It reduces the number of boards in the control unit, keeps the 0i-C control unit compact, and matches the needs of a 2-axis machine exactly.

Key Specifications

0i-TC — The Series This Card Was Designed For

The FANUC Series 0i-TC (Series 0i Turning Centre, Model C) is the lathe-configured variant of the 0i-C platform. Where the 0i-MC serves machining centres with 3 or more axes, the 0i-TC is optimised for turning operations — specifically the 2-axis (X and Z) configuration that covers the vast majority of CNC lathe applications.

The A20B-8200-0361 is the only servo/graphics card in the 0i-TC system. The complete 0i-TC control unit consists of: the main 0i-C PCB, the FROM/SRAM memory card, this combined FSSB/graphics card, and the LCD panel. This compact four-element stack is the complete electronic brain of the lathe.

When the A20B-8200-0361 fails, both the display and the servo communication stop simultaneously. The lathe cannot move its axes (no FSSB commands) and cannot display any content (graphics function lost). Both symptoms together are characteristic of this dual-function card.

Application Scenarios

0i-TC lathe blank display and servo alarm: A 0i-TC CNC lathe powers on but shows a blank display and immediately generates servo alarm codes. Both symptoms occurring together confirm the A20B-8200-0361 is the failed component rather than separate servo or display failures. Replacement restores both functions simultaneously.

Lathe CNC refurbishment: An older 0i-TC lathe control unit undergoes a board-level refurbishment. The A20B-8200-0361 is replaced alongside the main board and memory card to reset the entire control unit's electronic service life.

FAQ

Q1: Can the A20B-8200-0361 be used on the 0i-MC (machining centre) version of the 0i-C platform?

No. The A20B-8200-0361 is designed exclusively for the 0i-TC (turning centre) configuration with exactly 2 FSSB servo channels (X and Z axes). The 0i-MC machining centre variant uses a different servo/graphics card with additional FSSB channels to cover 3 or more axes. The physical boards are different and are not interchangeable between the TC and MC variants.

Q2: Does replacing the A20B-8200-0361 require reconfiguring the FSSB axis assignments?

FSSB axis assignment parameters are stored in the CNC's SRAM parameter memory — not in the A20B-8200-0361 card itself. After fitting the replacement card, the CNC reads the existing FSSB parameters and re-establishes communication with the servo amplifiers. No FSSB parameter re-entry is required if the SRAM module is transferred intact from the original system.

Q3: What are the CNC system designations compatible with the A20B-8200-0361?

Compatible systems carry designations in the A02B-03xx-Bxxx range — specifically the 0i-TC configurations. The main 0i-C PCB (A20B-8200-039x) is the host board. Confirm the specific system designation from the machine's documentation before ordering.

Q4: If only the display fails on a 0i-TC lathe, does the A20B-8200-0361 need replacement?

Because the FSSB servo and graphics functions share the same physical board, a display failure on a 0i-TC lathe that has no servo alarms can still indicate a partial A20B-8200-0361 fault. Before concluding the card is faulty, verify the LCD backlight and LCD panel itself are functioning. If the LCD hardware is confirmed intact and the display remains dark or corrupted, the A20B-8200-0361's graphics section has likely failed and the board requires replacement.

Q5: What backup data is critical before replacing the A20B-8200-0361?

The A20B-8200-0361 card itself holds no stored data. Data is held in the FROM and SRAM memory cards. Before replacing the A20B-8200-0361, perform a complete backup of all CNC parameters, part programmes, tool offsets, and work offsets via the CNC's ALL IO backup function. If the SRAM battery is also showing a low voltage warning, replace it first to avoid losing SRAM data during the board replacement.