The VI Hierarchy window displays a graphical representation of all open LabVIEW projects and targets, as well as the calling hierarchy for all VIs in memory. The window displays the following items:

• Projects and targets
• Static and dynamic subVI calls
• Type definitions
• Global variables
• Shared variables
• LabVIEW classes
• XControls
• Statecharts
• Project libraries .lvlib
• Express VIs
• Static VI references

Select View»VI Hierarchy to display the VI Hierarchy window. Use this window to view the subVIs and other nodes that make up the VIs in memory and to search the VI hierarchy.

The VI Hierarchy window displays a top-level icon to represent the main LabVIEW application instance, under which appear all the objects that are not part of a project or are not part of the application instance for a project. If you add a project, the VI Hierarchy window displays another top-level icon to represent the project. Each target you add appears under the project.

As you move the cursor over objects in the VI Hierarchy window, LabVIEW displays the name of each object in a tip strip. You can use the Positioning tool to drag an object from the VI Hierarchy window to the front panel or block diagram of another VI to use the object in that VI. You also can select and copy a node or several nodes to the clipboard and paste them to other front panels or block diagrams. Double-click a VI in the VI Hierarchy window to display the front panel of that VI.

The VI Hierarchy window is a dynamic view of what is in memory. If you rearrange items in the hierarchy, LabVIEW does not save the new position of items. When you close and then reopen the VI Hierarchy window, the positions regenerate.

A VI that contains subVIs has an arrow button on its bottom border. Click this arrow button to show or hide subVIs. A red arrow button appears when at least one subVI is hidden. A black arrow button appears when all subVIs are displayed. If a VI contains recursive calls, the VI Hierarchy window shows this relationship by drawing a dotted line between the recursive VIs.