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Example Code

History Probes

Products and Environment

This section reflects the products and operating system used to create the example.

To download NI software, including the products shown below, visit ni.com/downloads.

    Software

  • LabVIEW

Code and Documents

Attachment

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Description

NOTE: History probes ship by default with LabVIEW 2019 and later. The probes provided below should only be used with LabVIEW 2018 and previous.

 

Overview

A set of custom probes that display a history of values that have passed through the wire.

 

Description

These "History Probes" extend the normal functionality of wire probes by displaying a history of the values that have passed through a wire. They support the following scalar

  • Integers:  U8, I8, U16, I16, U32, I32
  • Floating Point:  SGL, DBL, EXT
  • Complex Floating Point:  CSG, CDB, CXT
  • String
  • Path 

Each probe includes a "Reset on Next Run" button that allows you to reset the displayed history the next time the custom probe executes, i.e. the next time data flows through the wire. 

 

Requirements

  • LabVIEW 7.0 or later

 

Steps to Implement or Execute Code

Follow these instructions to install and use the History Probes:

  1. Unzip the attached file in your LabVIEW Data\Probes folder.  It should create a folder called "History Probes" in that folder.  In Windows, the LabVIEW Data folder is usually located in C:\Documents and Settings\[your username]\My Documents (Windows XP) or C:\Users\[your username]\Documents (Windows 7).  If you are unable to locate this folder, you can instead unzip the "HistoryProbes" folder into your LabVIEW\user.lib\_probes folder
  2. Once the files have been installed, run LabVIEW and open a VI.  Right-click on an appropriate data type wire (see above) and choose "Custom Probe > [type] with History.vi".  For example, if you right-clicked an I32 wire, you would select "Custom Probe > I32 with History.vi"
  3. Run the VI.  As the VI is running, you can view a history of the values that have flowed through that wire during the VI's execution

 

Note: Each probe indicates the datatype of the wire in its "Value" column header.  Also, each probe's contents can be reset during execution with the "Reset on Next Run" button.  Finally, you can change the display type of integer values to Decimal, Hexadecimal, Octal, or Binary. 

  

Additional Information or References

 

Way to select a custom probe in Step 2

1.png

 

Custom Probe Watch Window when VI is running

2.PNG

 

 

**This document has been updated to meet the current required format for the NI Code Exchange.**

Example code from the Example Code Exchange in the NI Community is licensed with the MIT license.

Comments
Jolyon
Member
Member
on

Really handy for seeing what's going on inside loops!  How did I ever manage without!

This is the droid you're looking for...
magyar
Member
Member
on

extremely useful!

Scientia est potentia!
Yardov
Active Participant
Active Participant
on

Made something similar sometime ago and serves a similar purpose. I used it for debugging measurement performance and accuracy. Enjoy:

https://decibel.ni.com/content/people/Yardov/blog/2014/05/23/statistics-probes

Gerardo O.
RF SW Engineering R&D
National Instruments
EduNI
Member
Member
on

@Yardov, the link provided results in an Access Denied message.