Skip to content Skip to navigation

OpenStax_CNX

You are here: Home » Content » Debugging Techniques

Navigation

Lenses

What is a lens?

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

This content is ...

Affiliated with (What does "Affiliated with" mean?)

This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.
  • NSF Partnership display tagshide tags

    This module is included inLens: NSF Partnership in Signal Processing
    By: Sidney BurrusAs a part of collection: "LabVIEW Graphical Programming Course"

    Click the "NSF Partnership" link to see all content affiliated with them.

    Click the tag icon tag icon to display tags associated with this content.

  • National Instruments display tagshide tags

    This module is included in aLens by: National InstrumentsAs a part of collection: "LabVIEW Graphical Programming Course"

    Comments:

    "A full introductory course on programming with LabVIEW."

    Click the "National Instruments" link to see all content affiliated with them.

    Click the tag icon tag icon to display tags associated with this content.

Also in these lenses

  • Lens for Engineering

    This module is included inLens: Lens for Engineering
    By: Sidney Burrus

    Click the "Lens for Engineering" link to see all content selected in this lens.

  • eScience, eResearch and Computational Problem Solving

    This module is included inLens: eScience, eResearch and Computational Problem Solving
    By: Jan E. OdegardAs a part of collection: "LabVIEW Graphical Programming Course"

    Click the "eScience, eResearch and Computational Problem Solving" link to see all content selected in this lens.

Recently Viewed

This feature requires Javascript to be enabled.

Tags

(What is a tag?)

These tags come from the endorsement, affiliation, and other lenses that include this content.
 

Debugging Techniques

Module by: National Instruments. E-mail the author

Summary: In this section, you will learn about LabVIEW debugging techniques.

brokrun.png If a VI does not run, it is a broken, or nonexecutable, VI. The Run button often appears broken, shown at left, when you create or edit a VI. If it is still broken when you finish wiring the block diagram, the VI is broken and will not run. Generally, this means that a required input is not wired, or a wire is broken.

Finding Errors

Click the broken Run button or select Windows>>Show Error List to display the Error list window, which lists all the errors. Double-click an error description to display the relevant block diagram or front panel and highlight the object that contains the error.

Execution Highlighting

exehilit.png View an animation of the execution of the block diagram by clicking the Highlight Execution button, shown in Media 2. Execution highlighting shows the flow of data on the block diagram from one node to another using bubbles that move along the wires. Use execution highlighting in conjunction with single-stepping to see how data move from node to node through a VI.

note:

Execution highlighting greatly reduces the speed at which the VI runs.

Single-Stepping

Single-step through a VI to view each action of the VI on the block diagram as the VI runs. The single-stepping buttons affect execution only in a VI or subVI in single-step mode. Enter single-step mode by clicking the Step Over or Step Into button. Move the cursor over the Step Over, Step Into, or Step Out button to view a tip strip that describes the next step if you click that button. You can single-step through subVIs or run them normally.

glyphrun.png If you single-step through a VI with execution highlighting on, an execution glyph, shown in Media 3, appears on the icons of the subVIs that are currently running.

Probes

probe.png Use the Probe tool, shown in Media 4, to check intermediate values on a wire as a VFI runs. When execution pauses at a node because of single-stepping or a breakpoint, you also can probe the wire that just executed to see the value that flowed through that wire.

You also can create a custom probe to specify which indicator you use to view the probed data. For example, if you are viewing numeric data, you can choose to see that data in a chart within the probe. To create a custom probe, right-click a wire and select Custom Probe>>New from the shortcut menu.

Breakpoints

brkpoint.png Use the Breakpoint tool, shown in Media 5, to place a breakpoint on a VI, node, or wire on the block diagram and pause execution at that locatiFon. When you set a breakpoint on a wire, execution pauses after data pass through the wire. Place a breakpoint on the block diagram workspace to pause execution after all nodes on the block diagram execute. When a VI pauses at a breakpoint, LabVIEW brings the block diagram to the front and uses a marquee to highlight the node or wire that contains the breakpoint. LabVIEW highlights breakpoints with red borders for nodes and block diagrams and red bullets for wires. When you move the cursor over an existing breakpoint, the black area of the Breakpoint tool cursor appears white. Use the Breakpoint tool to click an existing breakpoint to remove it.

Content actions

Download module as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Add module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks