Mitsubishi Electronics FX3G User Manual

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FX
3S
/FX
3G
/FX
3GC
/FX
3U
/FX
3UC
 Series
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) FX
3G
/FX
3GC
 PLCs
b) FX
3U
/FX
3UC
 PLCs
2. Memory cassette backup method
a) FX
3S
/FX
3G
 PLCs
b) FX
3U
/FX
3UC
 PLCs
3. EEPROM memory (built in PLC) backup method
a) FX
3S
/FX
3G
/FX
3GC
 PLCs
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
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 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
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 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.)