8.14.5 Common Settings (Symbol Variables) Settings GuideIf variables are set to retentive, they are stored in backup memory (SRAM) and retain their values when the unit is shut down.
These values are kept until the backup battery runs out, which causes these variables to revert to their default value as defined in GP-Pro EX. When shutting down or resetting the display unit, the latest values are copied to SRAM.
8.14.5 Common Settings (Symbol Variables) Settings Guide
For details about backup memory (SRAM), please see the following.
2.3 About the Display Unit's Internal Data
Data saved in backup memory (SRAM) is lost if the battery is drained while the power is turned off. In such case, the values specified in GP-Pro EX are used as the default values.
If a transfer occurs under one of the following conditions, all variables, including Retentive Settings variables, are reset.
In the [Transfer Settings] dialog box's [Transfer Settings] tab, under [Initialize], [Variable Value] is selected.
In [System Settings] - [Display Unit] - [Logic], under [Register Variable], [Address Format] is selected.
Different projects are transferred.
Refer to the following for models that support the variable's Retentive Settings.
1.5 Supported Features
The allowable number in [Retentive] is specified in the [Retentive Area Settings] in the System Settings [Logic Program] page.
30.15.1 Logic Program Settings Guide
You can check the Retentive/Volatile settings. From the [File] menu, point to [Information] and click [Project Information]. In the dialog box, select [Memory Usage], click the [Logic] tab, and in the [Variable Capacity] area click [Details].
The timing at which variables defined in the [Retentive Settings] are backed up is after the address refresh process has run its course. (Depending on the timing when the display unit is turned off or reset, the display unit may not back up the latest data of variables.)
30.14.3.3 Address Refresh