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 CRT 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 one or two 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 910 (SRAM parity alarm) to occur because the contents of
memory are lost. Clear the entire memory and reenter data after replacing
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:
If an unspecified battery is used, it may explode.
Replace the battery only with the specified battery
A02B–0200–K102 for power supply AI and BI.
A02B–0177–K106 for power supply C.
Dispose of used batteries as follows:
Discharge the batteries and dispose of them as ordinary nonflammable
Battery for Memory