Mitsubishi Electric MELSEC FX3U Programming Manual page 42

FX /FX /FX Series Programmable Controllers
3G 3U 3UC
Programming Manual - Basic & Applied Instruction Edition
Caution
Programs (when a memory cassette is not attached), latched (battery backed) type device values and clock
data are not backed up correctly when the battery voltage becomes low due to expiration of the battery life or
another reason.
In such a case, clear latched (battery backed) type devices, transfer programs again (when a memory
cassette is not attached), and then set initial values and clock data if necessary.
→ For a rough guide to the life and replacement of the battery, refer to the respective PLC User's
40
→ For the latched type device initialization method, refer to Subsection 2.6.5.
2 Overview (Sequence Program)
2.6 Program Memory and Devices
Manual [Hardware Edition].