
3.I/O SIGNALS (CNC ↔ PMC) FANUC AC SPINDLE MOTOR αi series B-65280EN/05
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(n) Motor power turn-off signal (MPOFA)
(1) When an abnormality occurs during spindle synchronous control
or during machining with a machine such as a gear machining
tool, this signal is used to immediately turn off the power to the
spindle motor and allow the motor to run freely.
(2) This signal turns off the motor power only.
(3) The motor power can be supplied again after the motor is
stopped (zero speed signal SSTA = 1). Even when this signal is
canceled, the power cannot be supplied while the motor is
rotating (SSTA = 0).
(4) After turning off the motor power, cancel all operation modes to
ensure safety. After the motor is stopped (SSTA = 1), specify
operation modes again.
When the power is turned off during position control, the
position control operation is performed continuously, so an alarm
such as an alarm due to an excessively large position error may
be issued.
Operation mode examples:
- Forward rotation command (SFRA)
- Reverse rotation command (SRVA)
- Spindle orientation (ORCMA)
- Rigid tapping (RGTP, RGTAP)
- Spindle synchronous control (SPSYC, SPPHS)
- Spindle positioning
- Cs contour control (CON, SCNTR1, SCNTR2, and so on)
- Speed difference mode (DEFMDA)
(5) Sample sequence
Free running
Motor speed
Motor power
Zero speed detection
signal SSTA
Motor power turn-off
signal MPOFA
Operation mode SFRA,
etc.
ON
OFF
ON
OFF
1
0
1
0
0min
(6) If bit 2 of parameter No. 4009 is set to 1, the motor power can be
turned off immediately when SPM alarm 24 (serial transfer data
error) occurs. Normally, when SPM alarm 24 occurs, the spindle
motor is decelerated then stopped.
(o) Synchronous orientation request command (SORSLA)
For details of this signal, see Section 5.5, "SPINDLE ORIENTATION
DURING SPINDLE SYNCHRONIZATION CONTROL", in Part I.