
4. POWER SUPPLY CONNECTION
B–64113EN/01
46
In a system using this CNC, batteries are used as follows:
Use
Component connected to
battery
Memory backup in the CNC control unit CNC control unit
Preservation of the current position indicated
by the separate absolute pulse coder
Separate detector interface
unit
Preservation of the current position indicated
by the absolute pulse coder built into the motor
Servo amplifier
Used batteries must be discarded according to appropriate local
ordinances or rules. When discarding batteries, insulate them by using
tape and so forth to prevent the battery terminals from short–circuiting.
Part programs, offset data, and system parameters are stored in CMOS
memory in the control unit. The power to the CMOS memory is backed
up by a lithium battery mounted on the front panel of the control unit. The
above data is not lost even when the main battery goes dead. The backup
battery is mounted on the control unit at shipping. This battery can
maintain the contents of memory for about a year.
When the voltage of the battery becomes low, alarm message “BAT”
blinks on the display and the battery alarm signal is output to the PMC.
When this alarm is displayed, replace the battery as soon as possible. In
general, the battery can be replaced within two or three weeks, however,
this depends on the system configuration.
If the voltage of the battery becomes any lower, memory can no longer
be backed up. Turning on the power to the control unit in this state causes
system alarm 935 (ECC error) to occur because the contents of memory
are lost. Clear the entire memory and reenter data after replacing the
battery.
Therefore, FANUC recommends that the battery be replaced once a year
regardless of whether alarms are generated.
The power to the control unit must be turned on when the battery is
replaced. If the battery is disconnected when the power is turned off, the
contents of memory are lost.
Observe the following precautions for lithium batteries:
WARNING
If an unspecified battery is used, it may explode.
Replace the battery only with the specified battery
(A02B–0200–K102.)
In addition to the Lithium battery built into the CNC control unit,
commercial D–size alkaline batteries can be used by installing the battery
case externally.
NOTE
A lithium battery is installed as standard at the factory.
4.4
BATTERIES
4.4.1
Battery for Memory
Backup (3VDC)