Fanuc DRAM module for 16i/ 18i/ 21i A20B-3900-0042

A20B-3900-0042 is a printed circuit board (PCB) used in CNC control systems manufactured by FANUC.

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📌 Basic Information

• Part Number: A20B-3900-0042

• Type: Printed Circuit Board (PCB)

• Category: Control / Interface Board

• Used In: FANUC CNC controllers (commonly Series 0i / 16i / 18i / 21i / 30i, depending on the machine configuration)

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⚙️ Main Functions

The A20B-3900-0042 board is used for internal communication and signal processing within the CNC control system.

Typical functions include:

• Processing control signals

• Communication between CNC modules

• Interface management with other boards

• Supporting overall CNC controller operation

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🧩 Installation Location

This PCB is typically installed:

• Inside the CNC control cabinet

• On the main control rack / motherboard

• Connected to other boards through the FANUC system backplane

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🔎 Board Series

The A20B-3900 board family includes several PCB modules used for specific control, interface, or communication functions within FANUC CNC systems. Differences between models usually involve:

• Hardware revision

• System compatibility

• Machine builder configuration

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✅ Simple explanation:
A20B-3900-0042 = FANUC internal CNC control PCB used for signal processing and communication inside the CNC controller. 🔧