Overview
The VarArchiver is used to back up and back up variable values. Either variable values of VisXpert memory variables or variables from the controllers can be saved and reloaded if necessary. This backup method can therefore also be used if values are not included in e.g. of a PLC or held/stored in the database.
For example, the values to be secured can be PLC data (parameters, setpoints, etc.) as well as manual operator input.
This stand-alone VisXpert module can perform the configured backups cyclically at predetermined intervals during the running application. However, the backup of the data is also manual via a command interface, e.g. by pressing a button in the visualization as well as via the procedure module of the VarArchiver.
Configuration
To use the VarArchiver, it must be included in the configuration of the communication module in the project. After that, the editor can be started. Pro VarArchiver module can only be configured for the variable values to be backed up. If several different backup jobs are required, several modules must be integrated into the project accordingly.
Before opening the editor module, the command interface must have a system group for the VarArchiver (e.g. “$VarArchiver1). This can be a local or global group, depending on the requirement and structure of the variable values to be backed up.
Basic
In order to archive variables, the basic settings for the backup must first be created:
- Variable archive: The variable archive specifies the path in which the archive.xml file should be stored. By default, the path is the project path of the application with its VarArchiver module. The Archive.xml file stores the backed-up variables and their values.
- System group: The system group is a variable group in which the system variables are located as a command interface. The system group is “VarArchiver”. However, this system group must first be created from the Memory module (see Description “Remote control from other modules)
- Archive interval: Here the time interval can be selected from a drop-down list, whereby the variable values are automatically saved at the appropriate time interval.
Variable selection
In the lower section, all variable groups in the VisXpert are displayed on the left. Selecting a variable group lists the variables associated with the group in the right pane. By selecting a group and pressing the arrow key above it, all variables in the group are selected. To select individual variables, they must be marked in the right area and taken over with the arrow key above.
All variables applied to the backup are listed in the middle pane under “VarName” with group name and variable name. Variables can be removed from this ‘backup list’ by selecting the record and pressing the key combination ‘Ctrl’ + ‘Delete’.
When the editor exits, the current settings are automatically saved.
Runtime
Different information is displayed in the flow module.
The variable values can be loaded, saved or start and stop the backup cycle. These commands can also be executed using the command interface for remote control of other modules.
At the top, the variable archive, system group, and archiving interval entries configured in the editor are displayed in milliseconds.
On the left side, all archive variables are displayed, the values of which are saved via the VarArchiver module. In the right pane, each variable returns its variable type and indicates whether a valid variable value exists for that variable after the last backup (Valid = True).
Manually backup/load variable values
Manual backup or restore (restore) variable values can only be performed if automatic cyclic backup is disabled.
Automatic, cyclic backup
In the VarArchiver, a greyed checkbox “Backup Active” is displayed next to the displayed archiving interval. If automatic backup is active, this checkbox will be hacked.
Remote control from other modules
For the VarArchiver, a system group must be specified in the configuration that contains the string variables command, status, and return. In the editor, the group name “VarArchiver” is displayed as default. To create this variable group, it is best to do the following:
- Create a new auxiliary variable group through the Memory module without any entries and exit the variable configuration.
- Entry of the name of the system group (name of the newly created auxiliary variable group) in the configuration of the VarArchiver.
- If you then open this system group again, it contains the string variables command, status, and return. Check the variable entries with the green hoe.
Command strings can be sent to the module via the command variable. The status variable gives information about the status of the currently processed command and takes the state busy during the execution of a command, while the state is otherwise set to “idle”.
It is not possible to pass multiple commands in a string at the same time. The commands must be passed to the interface individually.
The following commands are processed by the VarArchiver:
- BringToFront: Brings the VarArchiver’s expiration module to the foreground.
- Hide: Makes the VarArchiver invisible.
- Minimize: Minimizes the VarArchiver.
- StartBackup: Starts the automatic backup cycle with the parameterized time interval.
- StopBackup: Ends the automatic backup cycle.
- Backup: Saves the current variable values.
- Restore: Loads the most recently backed variable values to the variables.
