Occurrences Functions

LabVIEW 2018 Help

Edition Date: March 2018
Part Number: 371361R-01
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Owning Palette: Synchronization VIs and Functions

Requires: Base Development System. This topic might not match its corresponding palette in LabVIEW depending on your operating system, licensed product(s), and target.

Use the Occurrences functions to control separate, synchronous activities.


In particular, use these functions when you want one VI or part of a block diagram to wait until another VI or part of a block diagram finishes a task without forcing LabVIEW to poll.

You can perform the same task using global variables, with one loop polling the global variable until its value changes. However, global variables use more overhead because the loop that waits uses execution time. With occurrences, the second loop becomes idle and does not use processor time. When the first loop sets the occurrence, LabVIEW activates the second loop and any other block diagrams that wait for the specified occurrence.

Palette ObjectDescription
Generate OccurrenceGenerates an occurrence that you can pass to the Wait on Occurrence and Set Occurrence functions.
Set OccurrenceSets the specified occurrence. All nodes that are waiting for this occurrence stop waiting.
Wait on OccurrenceWaits for the Set Occurrence function to set the given occurrence.


Refer to the Simple Occurrence VI in the labview\examples\Synchronization\Occurrence directory for an example of using the Occurrences Functions.


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