A16B-2201-0851 Used Fanuc PLC Circuit Board 200w Amplifier PCB

A16B-2201-0851 | FANUC PMC-NB Printed Circuit Board — F15M / F15T / F15B CNC Machine Control PCB

What the PMC Does in a FANUC CNC System

CNC machine tools have two distinct control layers working simultaneously:

The CNC handles all axis motion, spindle speed, interpolation, and G-code programme execution — the precision machining functions.

The PMC (Programmable Machine Control) handles everything else: coolant on/off, chip conveyor control, door interlocks, tool changer sequences, hydraulic clamp logic, pallet transfer, operator panel lamps and pushbuttons. The PMC runs ladder logic programmes — essentially a PLC embedded within the FANUC CNC — and it executes independently of the CNC's motion programme.

The A16B-2201-0851 is the PMC-NB series control board that executes this machine sequence logic in the FANUC 15M (machining centre), 15T (turning centre), and 15B CNC systems.

Key Product Information

FANUC 15 Series — Machining, Turning, and B-Type Variants

The A16B-2201-0851 serves three CNC variants in the FANUC 15 series:

F15M (Machining Centre): The 15M CNC controls vertical machining centres, horizontal machining centres, and high-performance multi-axis milling machines. The PMC-NB handles the tool changer sequence, pallet shuttle, axis clamping, coolant management, and operator panel logic.

F15T (Turning Centre): The 15T CNC controls turning centres and lathes. PMC-NB functions include tailstock and steady-rest control, bar feeder interfaces, parts catcher sequences, and chuck/collet clamping logic.

F15B: A variant of the 15-series platform, also supported by the same A16B-2201-0851 PMC-NB board.

Application Scenarios

Tool changer fault diagnosis: A machining centre with FANUC 15M CNC develops a random tool change timeout alarm. The alarm occurs in the PMC's tool changer execution sequence. After ruling out mechanical causes, the PMC-NB board is identified as the fault source. Replacing the A16B-2201-0851 restores reliable tool change execution.

CNC repair and restoration: A FANUC 15T CNC system is being restored after a power fault event. Multiple boards are inspected. The PMC-NB board tests as failed and is replaced with the A16B-2201-0851. After PMC programme reload and machine sequence verification, the lathe returns to production.

Preventive spare stock: A production facility operating several FANUC 15-series CNCs maintains an A16B-2201-0851 as a critical spare, enabling rapid response to a PMC board failure without extended machine downtime.

FAQ

Q1: What happens to the PMC programme when the A16B-2201-0851 is replaced?

The PMC ladder programme is stored in non-volatile memory within the CNC system. In most 15-series configurations, the programme is retained in the CNC's memory independent of the PMC board itself. After replacing the A16B-2201-0851, the PMC programme is typically reloaded from a backup tape, RS-232 transfer, or I/O device. Always confirm that a valid PMC programme backup exists before replacing the board, and verify PMC programme operation through a full machine sequence test after installation.

Q2: What is the significance of the "W/O CAP" designation for A16B-2201-0851?

"W/O CAP" means the board is supplied without the battery backup capacitor. Some PMC-NB board variants include an onboard capacitor to retain SRAM memory contents during brief power interruptions. The W/O CAP variant relies on the system's battery backup or alternative memory arrangement for programme retention during power-off. When replacing an existing board, match the original board's configuration — W/O CAP or with capacitor — to maintain the system's memory retention design.

Q3: Can the A16B-2201-0851 be used across all FANUC 15 series models?

The A16B-2201-0851 is confirmed for FANUC 15M, 15T, and 15B. Other 15-series variants — such as 15MA or 15TA — may use the same or a different PMC board, depending on the specific CNC configuration and software version. Before fitting the A16B-2201-0851 into a system, confirm the target CNC model is 15M, 15T, or 15B, and verify that the board revision matches the installed CNC's expected PMC-NB hardware version.

Q4: Can the PMC-NB board be repaired, or is replacement always necessary?

Component-level PCB repair is technically possible for the A16B-2201-0851. FANUC CNC service companies offer board-level repair using original or equivalent component grades. Repair is a viable option when a confirmed direct replacement board is not available. For production-critical machines, board repair from a qualified FANUC repair specialist is an acceptable alternative to replacement, provided the repaired board undergoes functional testing before reinstallation.

Q5: Where in the CNC cabinet is the A16B-2201-0851 located?

In FANUC 15-series CNC cabinets, the PMC-NB board installs in the main control unit — the rack-mounted assembly containing the CPU board, axis control cards, and other CNC boards. The board location within the rack depends on the specific 15-series cabinet configuration and the system's total board complement. Refer to the FANUC 15M/15T/15B Hardware Manual for the specific slot assignment map of the installed system before removing or replacing the A16B-2201-0851.