Fanuc A16B-3200-0362 PC board tested in good condition A16B32000362 A16B-32OO-O362

A16B-3200-0362 | FANUC FS0i / 0i-A CNC Main CPU Board — Intel 486DX2 / SAS2 ASIC / F0i-A Master PCB

Main Board vs CPU Card — A Critical Distinction

Most A20B-3300-series items are plug-in CPU cards — small modules that slot into a separate main board. The A16B-3200-0362 is not a plug-in card. It is the main board itself — the master PCB that all other components mount onto.

This board carries the 486DX2 processor, the SAS2 ASIC, the bus connectors for option PCBs, the memory module sockets (FROM, DRAM, SRAM), the integrated PMC logic, and the machine I/O interface circuitry. Every board and module in the 0i-A control unit connects to or through the A16B-3200-0362. When this board fails, the complete CNC system fails.

Key Specifications

486DX2 and SAS2 — Two Processors, One Purpose

Intel 486DX2: Handles the CNC operating system, user interface, programme management, look-ahead calculations, and inter-system communication. Runs at 66 MHz internally through the 486DX2's characteristic 2× clock multiplication. The integrated floating-point unit (FPU) provides hardware-accelerated trigonometric and floating-point calculations required for interpolation.

SAS2 (Servo Axis System ASIC): A FANUC-designed Application-Specific Integrated Circuit that handles real-time servo loop arithmetic. The SAS2 executes current control loop calculations for the CNC's servo axes each update cycle, offloading this time-critical task from the general-purpose 486DX2. This division of labour allows both processor elements to stay within their real-time processing budgets — the 486DX2 focusing on CNC logic, the SAS2 focusing on servo dynamics.

Application Scenarios

Complete 0i-A CNC failure: A turning centre with FANUC 0i-A CNC fails to respond on power-up — no display, no axis power, no operator panel activity. The power supply tests correctly. The A16B-3200-0362 main board is identified as the failure. A replacement board, combined with a parameter and programme restore from backup, returns the machine to full production.

0i-A machine refurbishment: A machine tool dealer refurbishing an older 0i-A CNC machine replaces the A16B-3200-0362 as part of a full control unit overhaul, resetting the main board's service life alongside other ageing electronic components.

FAQ

Q1: What is the recommended data backup procedure before replacing the A16B-3200-0362?

Back up: (1) all CNC parameters via the CNC's ALL IO backup function to external media (CF card, USB, or RS-232C); (2) all stored part programmes; (3) tool offset and work offset data; (4) the PMC ladder programme and PMC parameters; (5) mastering data if the machine uses absolute encoders. Without this backup, restoring the machine after main board replacement requires contacting the machine tool builder for their original parameter data — a process that can cause extended downtime.

Q2: Can the A16B-3200-0362 operate with both 0i-MA (machining centre) and 0i-TA (turning centre) CNC software?

The A16B-3200-0362 main board hardware is common to the 0i-A platform regardless of machine type. The CNC software image stored in the FROM module determines whether the system operates as a machining centre (0i-MA) or turning centre (0i-TA) configuration. The board itself does not distinguish between M-type and T-type — the software configuration does.

Q3: Is the A16B-3200-0362 compatible with 0i-B CNC systems?

No. The 0i-A and 0i-B generations use different main board hardware with different processor and ASIC implementations, different memory module interfaces, and different option card bus specifications. These boards are not interchangeable. Confirm the 0i generation from the machine's CNC nameplate before ordering a main board.

Q4: What happens if the SAS2 ASIC fails on the A16B-3200-0362?

The SAS2 is soldered directly onto the main board PCB — it is not a separately replaceable component. If the SAS2 fails, the entire A16B-3200-0362 main board requires replacement. Symptoms of SAS2 failure typically manifest as servo-related alarms that appear immediately on enabling axis power, with no corresponding motor or encoder fault — the servo loop processing cannot complete, causing the CNC to alarm before axis motion begins.

Q5: How many option boards can be connected to the A16B-3200-0362?

The A16B-3200-0362 main board provides option card slots for the 0i-A's configuration options — servo interface cards, communication boards, and graphics modules. The total number of option card slots is defined by the main board layout and the 0i-A system design. For the specific configuration capacity of the 0i-A, consult the FANUC Series 0i Connection Manual (Hardware) for the A-generation system, which documents the option board slot assignments and physical configuration limits.