Fanuc Basic Unit for 21i A02B-0285-B502

A02B-0285-B502 is a CNC main control unit (controller module) used in advanced CNC systems from FANUC.

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📌 Basic Information

• Part Number: A02B-0285-B502

• Device Type: CNC Main Control Unit

• Controller Series: FANUC Series 31i / 32i / 35i (Model B)

• Category: High-performance CNC controller hardware

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⚙️ Main Functions

The A02B-0285-B502 works as the central processing controller of the CNC machine and performs:

• Execution of NC programs (G-code / M-code)

• Multi-axis motion control and interpolation

• Communication with servo amplifiers and spindle drives

• Running PMC (Programmable Machine Control) ladder logic

• Management of machine I/O signals

• Handling system alarms, diagnostics, and communications

• Control of the operator interface and display

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🔌 Typical System Connections

This controller is typically connected with:

• Servo amplifier modules

• Spindle amplifier

• I/O interface modules

• Operator panel / LCD display

• Memory and system software modules (such as A87L program packages)

• Machine sensors and safety signals

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🔎 Difference in the Same Series

Within the A02B-0285 controller family, versions like:

• B500

• B502

• B503

• B504

represent different hardware revisions or option configurations (for example memory size, interface options, or machine-builder customization).