Industrial robots from FANUC rely on main control boardsalso known as CPU or system boardsas the central hub for motion processing, I/O coordination, servo communication, and safety logic.
This compatibility guide helps engineers, maintenance teams, and procurement specialists:
- Identify correct main board generations
- Cross-reference part number formats
- Avoid controller mismatch failures
- Reduce unexpected robot downtime
Why Fanuc Main Board Compatibility Matters
Fanuc main boards coordinate multiple critical subsystems:
- CPU processing and motion control
- Servo drive and feedback communication
- Digital and analog I/O interfaces
- Safety chain and emergency stop logic
- Fieldbus and network communications
Installing an incorrect or incompatible board can result in:
- Controller boot failure
- Servo or axis alarms
- I/O or network communication loss
- Immediate production downtime
Correct compatibility verification is therefore essential before any replacement.
Fanuc Controller & Main Board Architecture Mapping
This structural table maps controller generations to their primary main board series identifiers for reference orientation only.
| Controller Generation | Main Board Series(PCB) | CPU Processor Tier | Compatible Logic Board | System Interface Module |
|---|---|---|---|---|
| Fanuc R-30iA | A16B-3200-060x | Core Logic Group | A20B-8101 | A16B-2204 |
| Fanuc R-30iB | A20B-8200-079x | Integrated Series | A20B-8201 | A20B-2101 |
| Fanuc R-30iB Plus | A20B-8201-013x | High-Speed Plus | A20B-8201 | A20B-2102 |
| Fanuc R-J3iB | A16B-3200-041x | Legacy Modular | A20B-3300 | A16B-2203 |
This mapping provides a generation-level overview, not a full spare-part listing.
Representative Hardware Classifications
Examples shown reflect common series identifiers rather than exhaustive part listings or specific stock availability.
| Component Category | Series Formats | Hardware Role |
|---|---|---|
| System Mainboards | A20B-8200 / A16B-3200 | Central Processing & Memory |
| CPU Modules | A20B-8201-008x | Logic Calculation & OS Runtime |
| SRAM/ROM Cards | A20B-3900 / A16B-2201 | Data Retention & Software Storage |
| Communication Cards | 20B-8101 / A17B-3300 | Fieldbus & Network Integration |
Core Fanuc Main Board Types
1. Alpha i / Alpha Main Boards
Common in M-710, R-2000, LR Mate, and ArcMate series.
| Part Number | Description | Compatible Robot Series |
|---|---|---|
| A20B-1001-0810/03A | Alpha i Main Board | M-710, R-2000 |
| A20B-1001-0830/03A | Alpha i CPU Board | LR Mate series |
| A20B-1001-0840/03A | Alpha i Motion Control Board | ArcMate series |
Compatibility tip: Ensure the firmware version matches the robot controller before replacement.
2. Beta / Alpha 6 Main Boards
Used in heavy payload robots and older Fanuc models.
| Part Number | Description | Compatible Robot Series |
|---|---|---|
| A20B-1001-0870/03A | Beta Main Control Board | M-900 / R-800 series |
| A20B-1001-0880/03A | Beta CPU & I/O Board | High payload ArcMate |
Replacement note: Beta boards require the correct servo interface boards to function properly.
3. Mini / Compact Main Boards
Used in light-duty or desktop robots, such as LR Mate series.
| Part Number | Description | Compatible Robot Series |
|---|---|---|
| A20B-1001-0801/03A | LR Mate Main Board | LR Mate 200iD, 210iC |
| A20B-1001-0802/03A | LR Mate CPU Board | LR Mate 200iC |
Failure signs: Controller fails to boot, servo alarms on all axes, or communication loss.
4. Fieldbus & Communication Interface Boards
Enable EtherNet/IP, PROFIBUS, DeviceNet, and Mechatrolink integration.
| Part Number | Description | Compatible Robot Series |
|---|---|---|
| A20B-1001-0920/03A | Fieldbus Interface Board | M-710, R-2000, LR Mate |
| A20B-1001-0930/03A | Network Interface Module | ArcMate, High Payload robots |
Notes: Mismatched communication boards often cause network timeout alarms or I/O errors.
How to Verify Main Board Compatibility
Before ordering a replacement:
- Check the part number printed on the existing board.
- Match firmware versions between the board and robot controller.
- Confirm robot series and controller model to ensure electrical and communication compatibility.
- Cross-reference with Fanuc service manuals or your trusted supplier catalog.
Skipping these steps can cause non-booting controllers or servo faults.
Replacement Strategy
Board-Level Replacement
- Replace only the failed board if other boards are functioning correctly.
- Saves cost and reduces downtime.
Full Controller Replacement
- Needed when multiple main boards fail or controller is obsolete.
- Ensures long-term reliability and safety compliance.
Related Index & Guides
To build a complete spare-parts navigation structure, see:
- Fanuc Part Number Index
- Fanuc Controller Boards & Modules Index
- Fanuc Servo Drive Index
- Robot I/O Modules & Expansion Cards Index
- Robot Communication Boards Index
These resources form a complete Fanuc robot spare parts and maintenance hub.
FAQ - Fanuc Main Boards
Q: Can I replace an Alpha i main board with an Alpha 6 board?
A: No. Each board generation has unique architecture and firmware. Replacements must match the robot model and series.
Q: How do I confirm the correct board part number?
A: Verify the board label, robot series, controller model, and firmware version before ordering.
Q: Are refurbished Fanuc main boards reliable?
A: Yes, if professionally tested for functionality, firmware, and electrical safety.
Q: Can communication boards from different robot series be interchanged?
A: No. Each series uses specific connectors, voltage levels, and protocols; always match the board to the robot series.
Q: What is the primary function of this Fanuc Main Board Compatibility Guide?
A: This index serves as a high-level structural map of Fanucs main processing hardware, categorizing main boards by their functional role and system generation. It is designed to provide part number prefix consistency for the fanuc-circuit-board collection.
Q: Are the part numbers listed here equivalent to official Fanuc standards?
A: Yes. All part number formats (e.g., A16B, A20B) correspond to official Fanuc hardware nomenclature as used across documentation and system references. This index focuses on established industry formats and series identifiers.
Q: Does this index cover specific software version compatibility?
A: No. This specific index is focused on physical hardware architecture. While hardware revisions are linked to software requirements, software versioning is categorized under separate firmware-specific reference guides.
Q: How are board revisions handled in this index?
A: This index maps the base series and generation (e.g., A20B-8201). Specific revision suffixes and minor hardware variations are addressed within the detailed product collections to which this index refers.
Reference Notes
This section provides supplementary reference links related to Fanuc main board architectures, electronic module classification, and system-level hardware logic.
Referenced materials are intended to support index navigation and structural orientation for Fanuc CPU and logic boards only. They are informational in nature and do not replace official Fanuc technical documentation, system manuals, or software release notes.