
B–63465EN/01
2. HARDWARE
53
The parameters are stored in the SRAM on 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. Even when the main power supply is
turned off, data is not lost if the battery is connected normally. The lithium
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” is
displayed on the DPL/MDI. Alarm information signal 2A #2 (BAL) is
used to send this alarm to the host controller via the HSSB. When a
DPL/MDI is not always connected to the machine, a battery alarm to
appear on the host controller. 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 battery voltage gets lower, it becomes impossible to back up the
content of the SRAM. Turning on the power to the in this state causes
system alarm 910 (SRAM parity alarm) to occur because the contents of
memory are lost. Clear the entire SRAM memory and reenter data after
replacing the battery. Data should be saved to the flash memory card or
floppy disk beforehand.
When replacing the memory backup battery, do so while the controller is
turned off.
The following two kinds of batteries can be used.
D Lithium battery built into the Digital Servo Adapter controller.
D Two alkaline dry cells (size D) in the external battery case.
(1)Prepare a new lithium battery (ordering drawing number:
A02B–0200–K102).
(2)Turn the machine (Digital Servo Adapter) on for about 30 seconds.
(3)Turn the machine (Digital Servo Adapter) off.
(4)Remove the old battery from the top of the Digital Servo Adapter
control unit.
First unlatch the battery, remove it from the holder, and detach its
connector. The battery holder is on top of the face plate (or the memory
connector) on the base printed–circuit board.
2.8
BATTERY
REPLACEMENT
2.8.1
Battery for Memory
Backup (3 VDC)
Replacing the lithium
battery