Fuji Electric MICREX-SX series SPF - Memory Backup and Internal Battery Specifications; Calendar Specifications

3-3
Section 3 Specications
3-2-2 Memory backup and internal battery specications
The primary battery built in the main unit cannot be replaced. When a voltage drop of the battery is detected, you need to
replace the main unit.
The battery connection switch is set to OFF at the factory shipment to save battery consumption. When you start using the main
unit, set the battery connection switch to ON to enable memory backup by the built-in battery.
For the details of the battery connection switch, see “3-11-1 Main unit” in “3-11 Names and Functions.”
Item Specication Remark
Backup area
Retain memory, retain attributed memory of
user FB and System FB instance memory,
RAS history, Calendar
Backup target parts: SRAM, RTC
Battery Graphite uoride lithium primary battery Built-in battery, 1000mA/h, Unreplaceable
Backup time 10 years or more Ambient temperature: 55°C
Battery voltage drop
detection function
Provided
(Updated approximately every 10 minutes
while the main power is ON.)
• When a voltage drop of the battery is detected (*1), the
PWR/BAT LED blinks alternately in red and orange.
The battery error in the system memory is set ON.
• When detected that the battery voltage is normal (*2),
the PWR/BAT LED lights up in red. The battery error in
the system memory is set OFF.
*1 2.4V or less
(battery voltage A/D conversion value 492)
*2 2.4V or more
(battery voltage A/D conversion value 493)
Battery voltage read
function
Provided
(Updated approximately every 10 minutes
while the main power is ON.)
• Battery voltage A/D conversion value is stored in the
special register “%MW1.61450 (WM61450).”
• Battery voltage
= Battery voltage A/D conversion value * 4.883 [mV]
* Battery voltage drop can be detected by an application.
Battery life Life of primary battery: 10 years
<Notes on battery connection switch>
When the battery connection switch is OFF, the battery voltage drop detection LED also blinks. Check the switch status.
<Notes on detection of battery voltage drop and primary battery life>
• The built-in graphite uoride lithium primary battery has a characteristic that its voltage is increased under a high ambient
temperature. Therefore, even if the battery voltage drop detection LED blinks at power-on of the main unit, it may turn OFF
as the temperature in the main unit rises while running.
• The remaining capacity of a graphite uoride lithium primary battery never recovers even if the ambient temperature is high.
If the ambient temperature is high and the battery remaining capacity is low, the battery voltage may rapidly drop as the
remaining capacity is consumed.
In addition, as a result of moisture absorption for a long period, self discharge of a graphite uoride lithium primary battery
may rapidly increase from some point to cause a rapid drop of the battery voltage.
• For the above reasons, if you conrm that the battery voltage drop detection LED blinks or when more than ten years have
passed since the date of shipment, promptly replace the main unit following the steps described in “5-2 Actions to be Taken
When Battery Voltage Drop is Detected” without turning off the power.
• If the battery voltage continues to decrease with the main power OFF, more and more data of the built-in SRAM can be
easily lost, which causes a memory backup error (retain memory loss) after the main power is turned ON. In addition, the
calendar may be stopped or delayed.
3-2-3 Calendar specications
Item Specication Remark
Range
Up to 31 Dec. 2069 23:59:59
Precision ±232 ppm (temperature: 25°C) ±20 sec/day
Time setting/change Loader, user application