
B–63003EN/04
4. POWER SUPPLY CONNECTION
61
Turn off the power to all the units at the same time, or in the following
sequence:
1 Power to the CNC (24 VDC)
2 Power to the slave I/O units connected via the I/O link,
separate detector interface unit, and stand–alone type LCD
unit (24 VDC), servo amplifier control power supply (200
VAC), and power to any separate detector (scale)
3 Power to the overall machine (200 VAC)
“Turning off the power to all units at the same time” means completing
the power–off operations in 2 and 3 above within 500 ms before the
power–off operation described in 1 above. If the power to the units
indicated in 2 or 3 is turned off other than within 500 ms of the power in
1 being turned off, alarm information is left in the NC.
The power–off sequence for a stand–alone type LCD unit supporting the
display link and an intelligent terminal is undefined.
CAUTION
When the i Series CNC with PC functions or an intelligent
terminal is used, the OS must be shut down before the
power to the control unit is turned off. Be careful not to turn
off the power while the hard disk is being accessed or before
the OS has terminated; otherwise, the hardware contents
may be destroyed.
When the power is turned off or when the power is momentarily
disconnected, motor control is disabled. Problems that may be generated
from the motor control disabled state should be handled from the
machine, as necessary.
For example, when movement along a vertical axis is controlled, a brake
should be applied to prevent falling. Usually, the brake clamps the motor
when the servo is not activated or when the motor is not turning. The
clamp is released only when the motor is turning. When servo axis control
is disabled by power–off or momentary power disconnection, the brake
usually clamps the servo motor. In this case, before the relay for clamping
operates, the controlled axis may fall. So, also consider whether the
distance the axis is likely to fall will cause a problem.
4.2.4
Power–off Sequence