Retain variables are set to initial values by device command 0x2022/43 (fixed as of V1.5)
Corrected from: Controller c520 V1.5
Controller c550 V1.5
Controller c750 V1.5
Response of the new version:
The device command 0x2022/43 restores the backup from the connected USB stick. The retain variables are set to the values stored in the backup.
What happens? After restoring a backup, the retain variables have their initial value.
When does the behaviour occur?
If a backup is restored to the controller via device command 0x2022/43 (Device command:Restore), the retain variables associated with the PLC project that were saved in the backup are reset to their initial values.
Which products are affected? Controller c520 from V1.0
Controller c550 from V1.0
Controller c750 from V1.0
Short-term measures:
Perform a restore as follows to restore the retain variable values saved in the backup:
Switch off the controller.
Insert the USB stick with the backup to be restored into the controller.
Switch on the controller. > The restore is started automatically. After restoring the project, the retain variables have the values from the backup.
Evaluation/Recommendations:
A restore of a backup is typically performed during device replacement or serial commissioning. If the restore is triggered via the device command 0x2022/43, then the power-failure-safe variables of the project are not set to the values previously saved in the backup. An applicative solution is described under Short-term measures.
