
B–63443EN/02
3. INSTALLATION
HARDWARE
23
Part programs, offset data, system parameters, and ladder are stored in
SRAM memory in the control unit. The power to the SRAM 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” or
“BAL” displays on the CRT or DPL display and the battery alarm signal
BAL < F001#2> 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 one or two weeks, however, this depends on the system
configuration.
If the voltage of the battery becomes any lower, contents of SRAM
memory can no longer be backed up. Turning on the power to the Power
Mate in this state causes system alarm (RAM parity alarm) to occur
because the contents of SRAM memory are lost. Clear the entire SRAM
memory and reenter data after replacing the battery. To clear and reenter,
it is required to save data in the memory card or floppy.
CAUTION
If the contents of the SRAM memory are not backed up, the
data may not be restored at the time of maintenance.
The power to the Power Mate 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–0118–K111).
Dispose of used batteries as follows:
D Small quantities
Discharge the batteries and dispose of them as ordinary nonflammable
garbage.
D Large quantities
Consult FANUC.
3.6.2
Battery for Memory
Backup