Commit Semantics

The Working Copy and Saving the Project

When you open a project, a copy of the project is made. This copy is called the working copy. When you are working in a project, all changes you make are stored in the working copy. It is only when you save the project (for example, using File-Save) that the original project file is updated.

Apply Buttons

All properties dialog boxes have Apply buttons. When you press the Apply button, the changes are stored in the working copy. Like all changes to the working copy, they are not stored in the project file until you save the project.

Immediate Data Transfer to Controller

Some data values are sent to the controller immediately after you enter them. This is indicated by a blue arrow to the right of an operand in the ladder, function block, and sequential function chart editors, or to the right of a control on a properties dialog box. When you see this blue arrow, the data will be sent to the controller when you press the <Enter> key or when you move the focus off of the control.

Language and Tag Editors

The individual language editors and Tag Editor don’t have Apply buttons. They apply their changes to the working copy automatically.

Automatic Apply

The

Logix Designer

application will automatically apply any edits on open Component Properties dialog boxes whenever you request any of the following operations:

Of course, when you request a File-Save or Save-As, edits are applied before the working copy is saved, and when you request a File-Close, you are first asked if you want to save the project.

Creating/Deleting Project Components

When you create (or delete) a project component, it is created (or deleted) in the working copy. If you are online, it is also created or deleted in the controller.

Creating Tags and Committing Modifications

In the Data Editor table, one tag or tag element is represented by a row in the grid. You can create a tag only in the Create Tag row in the Tag Editor window. As soon as you modify a cell in the Create Tag row, a new row gets appended at the end of the grid. A new tag gets created when you cursor off the Create Tag row and any error will get prompted.

The new tag gets inserted at the end of the list, independent of the filtering and sorting criteria.

Changes to an existing tag attribute gets committed when you cursor off the active cell except the value cell, therefore, there can be only one tag that has pending edits at any one time.

The application saves pending edits when:

Committing Value Edits

Any change to tag value is committed in a different semantic compared to the other tag attributes. These actions commit value pending edits either to the controller (online) or to the project file (offline):

In general, any action that causes the Tag Editor window to lose focus will cancel any value pending edit and revert the value back to the original. These events cancel pending edits: