I. Basic Information

Model: JANCD-FC904-1 (often abbreviated as FC904)

Brand: YASKAWA (Yaskawa Electric)

Board Number: DF9201374-B0 (Rev.B)

Applicable System: YASNAC I80 Series CNC Control Cabinet

Function: CNC Main Control / Axis Control Board (can control up to 8 axes)

Weight: Approximately 0.4 kg

Origin: Japan

II. Core Functions

Motion Control Core: I80 System Main CPU, responsible for interpolation, position loop, and speed loop calculations.

Multi-axis Control: Up to 8-axis servo / spindle control, supports linear, circular, and helical interpolation.

Bus Interface: Connects servo drivers (such as Σ series), I/O boards, operation panels.

I/O Management: Integrated digital input/output, compatible with machine buttons, sensors, solenoid valves.

System Bus: Cooperates with I80 backplane (JANCD-MB20, etc.), distributes power and signals.

III. Compatibility and Replacement

Compatible Backplane: JANCD-MB20 (I80 Motherboard)

Compatible Board Cards:

I/O Board: JANCD-FC903-1

Panel Interface: JANCD-FC900C-2

Replacement Model: FC904-1 is the final version, with no subsequent upgraded models

IV. Common Faults and Troubleshooting

No Display / No Power On: Check DC5V power supply, gold fingers cleaning, backplane slot contact.

Servo Alarm (ALM): Check servo bus wiring, encoder feedback, shielding grounding.

No Response of I/O Signals: Measure 24V power supply, terminal wiring, COM common terminal.

Axis Drift / Positioning Error: Clean gold fingers, reinsert card, check axis parameter settings.