Suspend execution of a subVI to edit values of controls and indicators, to control the number of times the subVI runs before returning to the caller, or to go back to the beginning of the execution of the subVI. You can cause all calls to a subVI to start with execution suspended, or you can suspend a specific call to a subVI.
To suspend all calls to a subVI, open the subVI and select Operate» Suspend when Called. The subVI automatically suspends when another VI calls it. If you select this menu item when single-stepping, the subVI does not suspend immediately. The subVI suspends when it is called.
To suspend a specific subVI call, right-click the subVI node on the block diagram and select SubVI Node Setup from the shortcut menu. Place a checkmark in the Suspend when called checkbox to suspend execution only at that instance of the subVI.
The VI Hierarchy window, which you display by selecting View»VI Hierarchy, indicates whether a VI is paused or suspended. An arrow glyph, shown as follows, indicates a VI that is running regularly or single-stepping.
A pause glyph, shown as follows, indicates a paused or suspended VI.
A green pause glyph, or a hollow glyph in black and white, indicates a VI that pauses when called. A red pause glyph, or a solid glyph in black and white, indicates a VI that is currently paused. An exclamation point glyph, shown as follows, indicates that the subVI is suspended.
A VI can be suspended and paused at the same time.
When you pause a subVI, the Call list pull-down menu on the toolbar lists the chain of callers from the top-level VI down to the subVI. This list is not the same list you see when you select Browse»This VI's Callers, which lists all calling VIs regardless of whether they are currently running. Use the Call list menu to determine the current instance of the subVI if the block diagram contains more than one instance. When you select a VI from the Call list menu, its block diagram opens, and LabVIEW highlights the current instance of the subVI.
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