Fanuc Alarm 749, 750 Serial Spindle Link Error Information by KFASLLC

KFAS: Fanuc CNC Parts, Service, & Repair

FANUC SERIAL SPINDLE COMMUNICATION ERRORS

749 S–SPINDLE LSI ERROR

Serial communication error while system is executing after power

supply on. Possible Causes:

1) Optical cable connection is fault or cable is not connected or cable

is cut.

2) MAIN CPU board or option 2 board is fault.

3) Spindle amp. printed board is fault.

If this alarm occurs when CNC power supply is turned on or when

this alarm can not be cleared even if CNC is reset, turn off the power

supply also turn off the power supply in spindle side.

750 SPINDLE SERIAL LINK START FAULT

This alarm is generated when the spindle control unit is not ready for

starting correctly when the power is turned on in the system with the

serial spindle.

Possible Causes:

1) An improperly connected optic cable, or the spindle control unit’s

power is OFF.

2) When the NC power was turned on under alarm conditions other

than SU–01 or AL–24 which are shown on the LED display of the

spindle control unit.

In this case, turn the spindle amplifier power off once and perform

startup again.

3) Other reasons (improper combination of hardware)

This alarm does not occur after the system including the spindle control

unit is activated.

4) The second spindle (when SP2, bit 4 of parameter No. 3701, is 1)

is in one of the above conditions 1) to 3).

See diagnostic display No. 409 for details.

#3 (SPE) 0: In the spindle serial control, the serial spindle parameters fulfill the

spindle unit startup conditions.

1: In the spindle serial control, the serial spindle parameters do not fulfill

the spindle unit startup conditions.

#2 (S2E) 0: The second spindle is normal during the spindle serial control startup.

1: The second spindle was detected to have a fault during the spindle

serial control startup.

#1 (S1E) 0: The first spindle is normal during the spindle serial control startup.

1: The first spindle was detected to have a fault during the spindle axis

serial control startup.

#0 (SHE) 0: The serial communications module in the CNC is normal.

1: The serial communications module in the CNC was detected to have a

fault.

751 FIRST SPINDLE ALARM DETECTION (AL–XX)

This alarm indicates in the NC that an alarm is generated in the spindle

unit of the system with the serial spindle. The alarm is displayed in form

AL–XX (XX is a number) on the spindle amplifier.

The CNC holds this number and displays on the screen.

752 FIRST SPINDLE MODE CHANGE FAULT

This alarm is generated if the system does not properly terminate a

mode change. The modes include the Cs contouring, spindle positioning,

rigid tapping, and spindle control modes. The alarm is activated if

the spindle control unit does not respond correctly to the mode change

command issued by the NC.

754 SPINDLE–1 ABNORMAL TORQUE ALM

Abnormal first spindle motor load has been detected.

761 SECOND SPINDLE ALARM DETECTION (AL–XX)

(This Alarm is For 2nd Spindle) Refer to alarm No. 751.

762 SECOND SPINDLE MODE CHANGE FAULT

(This Alarm is For 2nd Spindle) Refer to alarm No. 752.

764 SPINDLE–2 ABNORMAL TORQUE ALM

Same as alarm No. 754 (for the second spindle)

771 SPINDLE–3 ALARM DETECT (AL–XX)

Same as alarm No. 751 (for the third spindle)

772 SPINDLE–3 MODE CHANGE EROR

Same as alarm No. 752 (for the third spindle)

774 SPINDLE–3 ABNORMAL TORQUE ALM

Same as alarm No. 754 (for the third spindle)