Precautions - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Precautions

The following describes precautions on the memory copy function.
Automatic memory initialization
If there are differences in the data memory or an SD memory card, the "$MELPRJ$" folder is deleted from the data memory or
SD memory card, and the memory copy is executed.
If there are differences in the program memory or device/label memory, the memory is initialized, and the memory copy is
executed.
Thus, the ERROR LED of the standby system CPU module may flash when the memory copy with the engineering tool or the
memory copy with the special relay and special register is executed. This phenomenon is not an error. Follow the procedure
to turn off and on or reset the standby system CPU module.
Also, back up the data that is not supported by the memory copy and is stored in the "$MELPRJ$" folder, such as event
history, before executing the memory copy.
Restrictions
■Restrictions on memory copy execution
Do not execute the memory copy in the following cases.
• The standby system CPU module is off or being reset.
• During initial processing (when switched to RUN)
• The tracking cable has an error or is pulled out.
• An error occurs on a redundant function module.
• A system configuration in which communications via a redundant function module are unavailable is used.
• Different models of CPU module are used in the control system and standby system.
• Online operation from the engineering tool
• The systems are being switched.
• An online module change is being performed (for replacing a redundant function module or modules of the standby
system).
• In separate mode (for the automatic memory copy)
• The memory copy has been executed on the standby system.
• The memory copy is being executed.
• A value other than 03D1H is stored in SD1653 (for the memory copy with the special relay and special register).
• The memory copy has been executed on the standby system CPU module that does not support the program restoration
information write selection when the program restoration information is not written to the control system CPU module.
■Restrictions during memory copy execution
Do not execute the following functions during memory copy execution.
• Online operation from the engineering tool
• Operation of the RUN/STOP/RESET switch
• Removal of the SD memory card
• Online module change
• Powering off or resetting the CPU modules
• Removing tracking cables
Errors during memory copy
When the memory copy is completed with an error, the MEMORY COPY LED of the control system turns off and that of the
standby system flashes (at 1s intervals). In this case, the memory copy has not been normally executed on the standby
system CPU module.
After checking the error code of memory copy stored in SD1654 (Memory copy completion status) and eliminating the error
cause, execute the memory copy again. ( Page 833 List of Special Register Areas)
28 FUNCTIONS
474
28.4 Memory Copy from Control System to Standby System