The FANUC Series 21i-TB is a Model B CNC control platform for compatible turning machines and CNC lathes. FANUC classifies it as a T-series, one-path control. It was used in configurations ranging from conventional two-axis lathes to turning applications with additional axes and spindle-related functions.

This page covers the 21i-TB system family rather than one fixed hardware package. The basic unit, display, PCBs, software and machine data can differ between machines.

• 100% system functions tested before shipment
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• Testing video provided upon request

Product Details

Brand: FANUC
Series: FANUC Series 21i-TB
Alternative Formats: 21i TB, 21iTB, Series 21i Model B T
Product Type: CNC Control System
Control Category: T-Series for Turning Applications
Control Paths: One path
Basic Controlled Axes: 2 axes
Maximum Controlled Axes: Up to 4 axes including Cs axis; configuration dependent
Typical Applications: CNC lathes and turning centers
Generation: Series 21i Model B
Availability: Contact us with the complete system number
Testing: Functions tested under a matching FANUC configuration when supplied as an assembled system

Control Function

The FANUC 21i-TB coordinates axis movement, spindle commands, machine sequences and operator functions in a compatible turning machine. Capabilities depend on the machine-tool builder design and installed options.

FANUC documentation specifies two basic controlled axes and an expanded maximum of four controlled axes including the Cs axis. These figures describe the platform limit; they do not mean every system includes four servo axes, Cs contouring, driven tools or spindle synchronization.

Rigid tapping, polar interpolation, live tooling, custom macro, Manual Guide, Ethernet and other functions may require specific software options and hardware.

System Configuration

A 21i-TB installation can include the CNC basic unit, motherboard, power-supply hardware, LCD/MDI, PMC and machine software, servo and spindle interfaces, I/O and communication boards.

The name “21i-TB” alone does not define what is included. A bare basic unit, LCD-mounted control, operator panel and assembled CNC system are different products. Confirm the quotation and photographs before ordering.

Model Clarification

The 21i-TB is the turning version of the Series 21i Model B platform. It is different from:

• 21i-MB: M-series control for machining centers
• 210i-TB / 210is-TB: Separately designated control structures
• 21i-TA: Earlier Model A generation
• 0i-TB or 18i-TB: Different FANUC control families

Similar appearance does not guarantee hardware, software or data compatibility.

Compatibility Check

Please provide:

• Complete A02B or A13B system number
• CNC nameplate and serial information
• Basic-unit, motherboard and PCB numbers
• Display size, orientation and connectors
• CNC software series and edition
• Number of controlled axes and spindles
• Servo and spindle interface configuration
• Machine manufacturer and model
• Current alarms and failure symptoms
• Available system and SRAM backups
• Photographs of the original system

A replacement with the same 21i-TB name may not operate if its hardware, software or machine data differs from the original.

Backup and Installation Note

Before removing the control, back up all available parameters, PMC ladder, diagnostics, offsets, macro variables, programs, compensation and machine files. Installation and data restoration should be performed by qualified personnel. Incorrect data or option settings can cause alarms, missing functions or unsafe movement.

Sales and Support

REACO CNC supplies tested FANUC 21i-TB systems and components, including basic units, control boards, displays and operator-panel hardware.

Send the full control label and internal PCB photographs for an accurate quotation. Pricing cannot be confirmed from “21i-TB” alone because configurations vary by machine.

Contact us for availability, warranty and delivery time. Worldwide express shipping is available through DHL, UPS and FedEx.