Mitsubishi Q00JCPU User Manual page 512

6
FUNCTIONS
(7) Checking with special relay and special register
(8) Precautions
6
- 212 6.29 Latch Data Backup Function (to Standard ROM)
The status of execution of latch data backup to the standard ROM or restore operation
can be checked by SM671, SM676, SD671 to SD679.
The following shows precautions for backup of latch data.
1) Do not turn OFF power supply of the CPU module or perform reset operation
during backup of latch data. If executed, RESTORE ERROR (error code:
2221) occurs, and backup data is not restored. (The backup data is deleted.)
2) Even if the backup data exists, the device initial value has a priority over the
backup data when the device initial value is set.
Therefore, the device where the device initial value setting is made is
overwritten by the device data of the device initial value after reflecting the
backup data.
3) Even if the latch device or latch range setting is used, backup data has a
priority over it.
Therefore, even when data of latch device and latch range setting is changed,
it is overwritten by data backuped at the time of turning ON from OFF power
supply and canceling the reset.
4) Devices where local device range setting is made are not backuped. They are
initialized (cleared to 0) when turning power supply ON from OFF or canceling
the reset.
5) When the number of writing to the standard ROM exceeds 100,000 times
(FLASH ROM ERROR (error code: 1610)), backup may not be made normally.
6) Backup data cannot be deleted unless the backup data by remote operation is
deleted or storage destination memory (Standard ROM) of backup data is
formatted.
7) Perform the following operations after the latch data backup operation has
been completed, since they cannot be performed during latch data backup.
If executed, an error is displayed on GX Developer.
• PLC memory format (Standard ROM only)
• Latch data backup by remote operation
• Write during RUN (Ladder mode, write files during RUN, and function
block)
• Write a program memory to ROM
• Write to PLC (Flash ROM)