Company Events Academic Community Support Solutions Products & Services Contact NI MyNI

Timed Structures and VIs

LabVIEW 2013 Help

Edition Date: June 2013

Part Number: 371361K-01

»View Product Info

Owning Palette: Structures

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

Use the Timed Structures and VIs to control the rate and priority at which a timed structure executes its subdiagram, synchronize the start time of timed structures, create timing sources, and establish a hierarchy of timing sources.

Example

The VIs and functions on this palette can return Timed Loop Error Codes.

Palette ObjectDescription
Build Timing Source HierarchyCreates a hierarchy of timing sources based on the names you enter in timing source names.
Clear Timing SourceStops and deletes the timing source you created or specified for use by another resource. The VI clears the timing source when the current iterations of all active timed structures that reference the timing source complete.
Create Timing SourceCreates a 1 kHz, 1MHz, or software-triggered timing source you can use to control the execution of a timed structure. Each timing source has its own unit of timing and/or start time and does not start until the first timed structure that uses the timing source starts. You must manually select the polymorphic instance you want to use.
Fire Software-Triggered Timing SourceFires a software-triggered timing source. Use the Create Timing Source VI to create a software-triggered timing source.
Stop Timed StructureStops the Timed Loop or Timed Sequence structure you enter in name.
Synchronize Timed Structure StartsSynchronizes the start of Timed Loops or Timed Sequence structures you enter in timed structure names by adding the names to the synchronization group you specify in synchronization group name.
Timed LoopExecutes one or more subdiagrams, or frames, sequentially each iteration of the loop at the period you specify. Use the Timed Loop when you want to develop VIs with multirate timing capabilities, precise timing, feedback on loop execution, timing characteristics that change dynamically, or several levels of execution priority. Right-click the structure border to add, delete, insert, and merge frames.
Timed SequenceA Timed Sequence structure consists of one or more subdiagrams, or frames, timed by an internal or external timing source that execute sequentially. A Timed Sequence structure executes each frame only once and, unlike a Timed Loop, does not repeat iterations. Use the Timed Sequence structure when you want to develop VIs that execute only once with precise timing, execution feedback, timing characteristics that change dynamically, or several levels of execution priority. Right-click the Timed Sequence structure border to add, delete, insert, and merge frames.

Example

Refer to the Timed Loop.lvproj in the labview\examples\Structures\Timed Loop directory for an example of using the Timed Structures and VIs.


 

Your Feedback! poor Poor  |  Excellent excellent   Yes No
 Document Quality? 
 Answered Your Question? 
Add Comments 1 2 3 4 5 submit