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FX3G/FX3U/FX3UC Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
2 Overview (Sequence Program)
2.6 Program Memory and Devices
2.6.3 Types of backup methods against power failure
There are the following types of latch (battery backup) for the program memory and built-in PLC devices.
1. Battery backup method
a) FX3U/FX3UC PLC
b) FX3G PLCs
2. Memory cassette backup method
a) FX3U/FX3UC PLC
b) FX3G PLCs
3. EEPROM memory (built in PLC) backup method
a) FX3G PLCs
Item Description
Latched contents The battery backs up the RAM memory built in the PLC, latched (battery backed) type devices and clock data.
Maintenance The battery life is around 5 years, (when the ambient temperature is 25°C).
For replacement information, refer to the Users Manual [Hardware Edition] of each PLC.
Cautions
1) When the battery voltage becomes low, sequence programs and other latched (battery backed) contents are
lost.
2) When an optional memory cassette (flash memory) is mounted, it is not necessary to back up sequence
programs by the battery.
Item Description
Latched contents The optional battery backs up the RAM memory built in the PLC and clock data.
Maintenance The battery life is around 5 years, (when the ambient temperature is 25°C).
For replacement information, refer to the Users Manual [Hardware Edition] of each PLC.
Cautions When the optional battery voltage becomes low, the RAM memory built in the PLC and clock data is lost.
Item Description
Latched contents 1) The flash memory built into the memory cassette backs up sequence programs.
2) A battery is required to back up latched (battery backed) devices and clock data from failure.
Maintenance Maintenance is not necessary.
Cautions The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)
Item Description
Latched contents The EEPROM memory built in the memory cassette backs up sequence programs.
Maintenance Maintenance is not necessary.
Cautions The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)
Item Description
Latched contents The EEPROM memory built in the PLC backs up latched (EEPROM backed) type devices and sequence
programs.
Maintenance Maintenance is not necessary.
Cautions The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)