Types Of Backup Methods Against Power Failure - Mitsubishi Electric FX3G SERIES Programming Manual

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
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 /FX
3U
Item
Latched contents
Maintenance
Cautions
b) FX PLCs
3G
Item
Latched contents
Maintenance
Cautions
2. Memory cassette backup method
a) FX /FX
3U
Item
Latched contents
Maintenance
Cautions
b) FX PLCs
3G
Item
Latched contents
Maintenance
Cautions
3. EEPROM memory (built in PLC) backup method
a) FX PLCs
3G
Item
Latched contents
Maintenance
Cautions
40
PLC
3UC
The battery backs up the RAM memory built in the PLC, latched (battery backed) type devices and clock data.
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.
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.
The optional battery backs up the RAM memory built in the PLC and clock data.
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.
When the optional battery voltage becomes low, the RAM memory built in the PLC and clock data is lost.
PLC
3UC
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 is not necessary.
The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)
The EEPROM memory built in the memory cassette backs up sequence programs.
Maintenance is not necessary.
The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)
The EEPROM memory built in the PLC backs up latched (EEPROM backed) type devices and sequence
programs.
Maintenance is not necessary.
The upper limit is set to the number of times for overwriting.
(Refer to the Hardware Edition of the main unit.)
2 Overview (Sequence Program)
2.6 Program Memory and Devices
Description
Description
Description
Description
Description