Mitsubishi Electric MELSEC iQ-R Series User Manual page 414

Event history when memory copy is executed
Back up the event history before memory copy. The files before memory copy are deleted when executing memory copy, so
the files in the memory including the event history may be deleted and the event history before memory copy may be cleared.
1
*1 If the firmware version of the CPU module of the standby system is "20" or later, the event history before memory copy is not cleared.
Errors during memory copy execution
When the memory copy is completed with an error, the MEMORY COPY LED of the redundant function module turns off in the
control system and the MEMORY COPY LED flashes (in 1s interval) in the standby system. In this case, the memory copy
has not been normally executed to the CPU module of the standby system.
Check the error code stored in SD1654 (Memory copy completion status), eliminate the error cause, and execute the memory
copy again. ( Page 668 List of Special Register Areas)
When labels accessible from external devices are used
When executing the memory copy, pay attention to the firmware version of the CPU modules used.
Depending on the firmware version, an error may occur in the CPU module of the standby system.
In this case, the following operations enable external devices to access the labels: Read parameters and programs including
the global label setting file from the CPU module of the standby system, write them to the CPU module, and restart the CPU
module of the standby system only.
26 REDUNDANT FUNCTION
412
26.4 Memory Copy from Control System to Standby System
*