Mitsubishi Electric MELSEC iQ-R Series User Manual page 317

■Operation of the special relay and special register
The following figure shows the operations of the special relay and special register of when the upper limit value for the number
of CPU module backup data has been set.
Check the following at the timing on when the bit 5 of SD944 (Enable the upper limit value for the number of CPU module
backup data) is turned on, and enable the upper limit value for the number of CPU module backup data.
• The backup processing has not been executed (when no backup data folder (CPU data folder) exists in the SD memory
card).
• The value set in SD1353 (Upper limit value setting for the number of CPU module backup data) is within the range (1 to
100).
(1)
ON
SD944(bit5)
OFF
SD1353 0
SM1351 OFF
SD960 0
SM1350 OFF
END
(1) The upper limit value for the number of CPU module backup data is set. (0  10)
In redundant mode
The following describes the backup system in a redundant system.
■System A/B setting information
The system A/B setting information is backed up. Restore the data included in the CPU module backup of each system.
Manage SD cards so as to not accidentally restore the data to a different system by labeling the SD memory
cards for backup with the label "For A system" or "For B system" respectively.
■System status
The system status is not backed up. Therefore, even if system B is backed up in the control system or system A is backed up
in the standby system, each system starts up according to system A/B setting information.
■Operation mode
The operation mode is not backed up. Therefore, even if backed up in separate mode, the CPU module starts up in backup
mode after restoration. Before starting up the CPU module in separate mode, change the operation mode to the separate
mode after restoration.
■Setting to operate the CPU module in the status at data backup
Even if bit 15 of SD955 (Continuous operation with the status at backup) is on, the device/label data cannot be maintained in
the status at data backup. (A CPU module of the control system starts to operate in the STOP status and changes to the RUN
status after restoration of both systems. Therefore, the module changes the operating status in a similar manner.
The SFC program and event history operate in the status at data backup.
Therefore, set this setting when using the SFC program and event history in the status at data backup on the system that has
no problem even if the device/label data is operated from the initial status.
*1 For details on the operation of the CPU module at the operation status change, refer to the following.
Page 136 Operation Processing When Operating Status Is Changed
*2 When the firmware version of the CPU module is different between backup and restoration, the SFC program will perform initial start
regardless of selection for "Resume Start".
10
ON
10
ON
END END
* 2
22 CPU MODULE DATA BACKUP/RESTORATION FUNCTION
* 1
)
315
22.1 Backup Function
22