Panasonic FP0 User Manual page 52

Optional Memory
2.5 Backing Up the 10 K Step Type
Predicted life of internal backup battery
When the control unit is on (when power is supplied) the internal backup battery life will
differ depending on the ambient temperature. Refer to the table below to predict the life
of the internal backup battery.
Note: When the control unit is off (when power is not supplied), temperature has almost
no effect on the battery life.
Ambient temperature
55 C
45 C
40 C
35 C
34 C and less
Range of backup possible with the internal backup battery
− The range that the user specifies with the programming tool from among the computation
memories given below, will become the holding backup area.
1) Timer/counter (T/C)
2) Internal relay (R)
3) Data register (DT)
4) Step ladder
− If the user does not make a designation, the default setting range will become the backup
holding area.
− The clock/calendar timer value is also backed up.
− The program and system registers are held in EEP−ROM with no relation to the internal backup
battery.
Handling of the internal backup battery
It is not possible to replace the internal backup battery when it has been exhausted or has
exceeded its life span.
Cautions regarding the backup of data
− The clock/calendar timer value is backed up by the secondary battery.
− Begin use only after the secondary battery has been sufficiently charged.
For reference
To read and use the initial settings data when starting operation, you can also write the data to
EEPROM by using the F12 EEPROM read instruction and the F13 EEPROM write instruction.
If the power supply is turned off while the P13 instruction is being executed, data may not be
written in the EEPROM properly.
Also, the area where the internal relays, data registers and timer/counter are held may not be held
properly.
Do not turn off the power supply while the P13 instruction is being executed.
2 − 28
Internal backup battery life
Approx. 430 days (approx. 1 year)
Approx. 1,200 days (approx. 3 years)
Approx. 2,100 days (approx. 6 years)
Approx. 3,300 days (approx. 9 years)
Approx. 10 years
FP0