IAI X-SEL, Operation Manual

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Appendix
Appendix
2. Absolute-Data Backup Battery
If the XSEL controller is to drive an absolute-type actuator, an absolute-data backup battery must be installed in
the controller.
An absolute encoder is designed to retain rotation data and detect rotations using the power supplied from the
absolute-data backup battery, even when the controller’s control power is not supplied, thus allowing the
controller to resume positioning control immediately after the controller power is restored, without performing
home return.
<Backup Time>
The recommended replacement interval for the absolute-data backup battery is two years. This may be a little
misleading. It means that if the battery is left at ambeinet temperature of 40 C, it will retain the stored data for
two years. In normal operating conditions, the battery can retain data for a longer period.
As a guide, the battery will last for around four years if the controller is used at ambient temperature of 40 C with
the controller powered up 50% of the time.
<Battery Replacement>
To replace the absolute-data backup battery, open the panel on the front side of the absolute brake unit in the
controller and replace the battery in the battery holder.
It is recommended that the battery be replaced regularly in accordance with the power-on frequency/duration of
the controller.
The battery must be replaced as soon as the controller’s battery voltage monitor function generates a battery
voltage low alarm.
After an alarm is detected, a battery error will occur in approx. 10 days at ambient temperature of 20 C if the
power is supplied to the controller continuously. Once a battery error occurs, operations can no longer be
performed unless the battery is replaced and an absolute encoder reset is performed.
If the controller is not operated, the above periods should be reduced to 70% at 20 C or to 60% at 40 C.
The controller is designed so that the data will not be lost for at least 15 minutes without a battery if the controller
is not detecting a battery error. Keep in mind to complete the battery replacement—taking out the current battery
from the battery holder and placing a new battery in the holder—within 15 minutes.
To prevent the risk of data loss, you can use the PC software to evacuate the data in the SRAM to the flash
ROM and then reload the flash ROM data to the SRAM after a new battery is installed.
The absolute-data backup battery is replaced differently depending on whether a battery error has generated or
not. If an error has not been detected, all you need is to replace the battery and the absolute encoder need not
be reset. If an error has been detected, an absolute encoder reset will be required.