Topic: DMD0274
Edit History
Edit History maintains a list of the changes made during an edit session in selections called History Points. A history point is created any time that a sufficient number of changes are made to the Element Documentation, Ladder Logic, Rung Comments, System Configuration, Project Information, Memory Image or the User Document.
Edit History points are temporary, that is, they are automatically created during every editing session and then deleted when the project is closed. AutoSave and manual Project Backup are the proper ways to create permanent copies of the project.
The Edit History dialog is invoked by the Ctrl+Z keystroke combination, or the Edit-> Edit History menu selection, or clicking the "Edit History" button of the Edit Bar.
The Edit History dialog has three columns, the first column contains a simple sequence number, the second column contains a time stamp of when the Edit History point was created. The list of Edit History points is normally displayed with the latest change at the top of the list. The sort order can be changed by simply clicking the header of the "#", Date/Time, or Modified Areas column.
The third column lists the different areas of the project that were modified and prompted the creation of the Edit History Point. The following is a list of the items that can be displayed in the Modified Areas column:
Element Database - will appear in the list any time that a change has been made to the Element Documentation for any element in any code-block.
Comment Database - will appear in the list any time that a change has been made to any Rung Comment in any code-block.
Program - will appear in the list any time that a change has been made to the ladder logic in any code-block in the project, this includes inserting instructions from file, pasting rungs, Deleting rungs, Changing execution order, Compiling, Changing the code block configuration (.TimeSlice value, protection, etc.), Performing a Replace.
System Configuration - will appear in the list any time that a change has been made to the System Configuration, this includes the memory configuration, device configuration, the module configuration and the I/O configuration.
Comm Link - will appear in the list any time the project is opened with a different communication link than was used in previous online sessions.
Project Info - will appear in the list any time that a change has been made to the Project Properties page of this project.
Memory Image - will appear in the list any time a new Memory Image has been created, or a change has been made to an existing Memory Image.
Print Settings - will appear in the list any time a change has been made to the Print settings for this project.
Clicking the Details button will invoke a dialog that displays all of the individual items that were changed for each of the entries in the Modified Areas column. The first column contains a simple sequence number, the second column contains a time stamp of when the change occurred, the third column lists the Modified Area, and finally a description of exactly what was changed in that area. The list of Edit History points is normally displayed with the latest change at the top of the list. The sort order can be changed by simply clicking the header of the "#", Date/Time, or Modified Area column.
Show each change on a separate line - since there can be multiple changes for each of the Modified Areas, enabling this option will place each of the changes on a separate line instead of placing all of the changes on a single line.
Select - closes the Details dialog and returns to the Edit History dialog with the current Edit History point selected. Although the programmer can navigate up and down the list of details, all of the items in the list will be included when this Edit History point is selected.
Close - closes the Details dialog and returns to the Edit History dialog
<< Previous - move the cursor backwards through the entries in the list
Next >> - move the cursor forward through the entries in the list
Confirm Revert Operation
Clicking the Revert button to begin the reversion process using the data from highlighted Edit History point.
This process will close the currently open project, replace that project with the version of the files contained in the highlighted Edit History point, then re-open the reverted-to project.
Edit-History Generation Rate
As stated earlier, a history point is created any time that a sufficient number of changes are made to the Element Documentation, Ladder Logic, Rung Comments, System Configuration, Project Information, Memory Image, or the User Document. What constitutes as 'sufficient' for each of these areas differs because some of them are more critical than others. For example, a single change to the System Configuration is sufficient to cause a history point to be generated, whereas it takes multiple changes to the element documentation to be sufficient to cause a restore point to be generated.
The programmer has some control over the frequency that the history points are generated through the Edit-History Generation Rate slider that is found on the Global Tab of the Options dialog. The Options dialog is accessible through the Options button on the Offline toolbar, or the View-> Options menu selection, or by right-clicking in the Ladder View and selecting Options from the resulting menu.
The programmer can select either More Frequent, the default rate, or Less Frequent. Generally speaking, Less Frequent will generate history points at about 1/2 the default rate, and More Frequent will generate history points at about 2 times the default rate.
There is also an option to Disable the Generation of Edit History points altogether.
Edit History data is the \Temp\Restore sub-folder in Do-more Designer's Project folder. A folder for each Project will be created within the Restore folder, and each History generating event operation will create it's own sub-folder using the current date and time as the folder name.
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