Mitsubishi Electric MELSEC-Q00U(J)CPU User Manual page 294

(2) Automatic restoration using SD918
The backup data is automatically restored when the CPU module is powered off and then on or is reset.
(a) Formatting at automatic restoration
At the execution of automatic restoration, set whether to format drives except for the SD memory card with bit1
of SD918 (Restoration function setting). This setting is valid only when the value of SD917 (Restoration target
data setting) is 0 (all target data).
Bit1 of SD918
Off
On
(b) Operating procedure
1.
Set the data to be restored with SD917 (Restoration target data setting).
2.
Set the restoration target folder with SD919, SD920, and SD921.
(Setting is not required when bit13 of SD918 = ON.)
3.
Set each setting with bit1 and bit13 to 15 of SD918 (Restoration function setting).
4.
Turn on bit0 of SD918 (Restoration function setting).
5.
Power off and then on or reset the CPU module.
If a restoration is completed with an error and SM922 (Restoration error check flag) turns on, check SD922
(Cause of error occurred at restoration), take corrective action, and then restore the data again as necessary.
• Since the special register set for the automatic restoration is in the latch area, the setting data is hold.
• SD918 (Restoration function setting) holds the setting data when the CPU module is powered off and on or is
reset. Therefore, if the CPU module is powered off and on or is reset while bit0 (Execution of automatic
restoration) of SD918 is remaining in ON, the automatic restoration is executed again. If the automatic restoration
is not required at the next time the CPU module is powered off and on or is reset, turn off bit0 of SD918 after the
restoration is completed, and then power off and on or reset the CPU module.
(c) Operating status
Operating status of the automatic restoration can be checked by the LEDs on the front side of the CPU module.
Operating status
Before automatic restoration start
Automatic restoration in execution
Automatic restoration completed
Automatic restoration error
(3) Checking error
• Even when an error has occurred at a restoration by turning on SM1929, a diagnostic error is not detected.
In that case, the error code is stored in SD922 (Cause of error occurred during restoration).
• When an error has occurred at an automatic restoration using SD918, a diagnostic error is detected. Also,
an error code is stored in SD922 (Cause of error occurred during restoration).
( QCPU User's Manual (Hardware Design, Maintenance and Inspection))
292
No format
Format
MODE: On (green), SD CARD: On (green)
MODE: Flash (green), SD CARD: Flash (green)
MODE: On (green), SD CARD: On (green)
MODE: On (green), ERR: Flash (red), SD CARD: On (green)
Description
LED indication