460

Power off the machine and inspect all FSSB fiber optic cables (orange cables) between the CNC and amplifiers. Check connectors at both the CNC FSSB port and the amplifier FSSB IN/OUT ports for proper seating and locking tabs engaged.

Never look directly into fiber optic cable ends or connectors while system is powered on - laser light can damage eyes.

Remove fiber connectors and inspect ferrule ends for contamination, scratches, or cracks using a fiber scope if available. Clean connector ends with lint-free swabs and isopropyl alcohol or approved fiber cleaning pens. Check for visible light transmission through cable using a fiber optic light source.

Verify FSSB loop configuration is correct. Check CNC parameter 8101 (FSSB channel 1) and 8102 (FSSB channel 2) for proper axis assignments. Navigate to SYSTEM > PARAM and verify parameters match actual amplifier positions in the FSSB daisy-chain.

Temporarily swap the suspected fiber cable with a known good cable from another axis or spare. Power on and observe if alarm follows the cable (cable fault) or stays with the axis (amplifier fault). Check DIAGNOSIS > FSSB screen for communication status of each axis.

Check the servo amplifier LEDs for the affected axis. A functioning αi/βi series amplifier should show a green LED when powered and communicating. A red LED or no LED indicates power loss or hardware fault. Record any LED blinking patterns for reference to amplifier manual.

Verify 200V/220V AC control power and 3-phase main power supply to the amplifier using a multimeter at the amplifier input terminals (L1, L2, L3, L1C, L2C). Check fuses F1, F2 on the amplifier for continuity and replace if blown.

HIGH VOLTAGE: Verify lockout/tagout procedures before accessing amplifier terminals. Measure with appropriate PPE and insulated test equipment.

Access DIAGNOSIS > SERVO > FSSB screen and check the connection status for each axis. The disconnected axis will show 'NO RESPONSE' or blank status. Compare with functioning axes to confirm communication failure pattern.

If LED indicates no power or fault, check amplifier position in FSSB chain against parameters 8101/8102. Verify amplifier rotary switches (address settings) match the CNC parameter configuration. For αi series, check both the axis address switch and FSSB channel selection switch.

Check if multiple axes on the same FSSB channel show alarm 460. If channel 1 (typically X, Z axes) or channel 2 (typically Y, 4th axis) has multiple failures, suspect CNC-side FSSB port failure rather than individual amplifier issues.

Navigate to DIAGNOSIS > FSSB and verify FSSB channel status. Check FSSB_CH1 and FSSB_CH2 diagnostic registers for communication errors. If available on your control series, check parameter 8103 (FSSB error detection settings) and diagnostic numbers D0700-D0799 for detailed FSSB status.

Test by temporarily reassigning the affected axis to the opposite FSSB channel (if available and supported by wiring). Modify parameters 8101 or 8102 to move axis assignment, relocate fiber cable to other CNC FSSB port, and reboot. If alarm clears, original FSSB port is faulty.

Changing FSSB parameters requires careful documentation and machine builder knowledge. Improper settings can cause multiple axis faults or unexpected motion.