Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual page 280

Data logging function and backup
When the CPU built-in memory (function memory) is specified for the data storage destination memory in the data logging
function, the function memory is cleared after the CPU module is powered off or the RESET state is cleared. Thus, data
logging files are also cleared. To prevent data logging files from being lost, back up the files after the completion of file transfer
by the data logging file transfer function.
15 CPU MODULE DATA BACKUP/RESTORATION FUNCTION
278
15.1 Backup Function