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AmitKaria2k

Add "Watch Variable" Feature in LabVIEW

Status: Declined

Any idea that has not received any kudos within a year after posting will be automatically declined. 

For debug purpose TestStand and other programming languages provide a "Watch Expression" feature. Similar to this I would like NI to add "Watch Variable" feature in "View" menu:

 

Watch Variables In LabVIEW.png

 

When user would click on "Watch Variables" a he should be able to see all the locals and globals used in entire VI hierarchy and select the variable that he wants to Watch. These variable should be displayed in another floating GUI. This feature would be of immense help even when we want to debug an executable where probes can't be used.

 

Thanks

Amit Karia

7 Comments
Norbert_B
Proven Zealot

You should not use local and global variables.

That being said, LV provides "probes" for watching data values passed by wires. So essentially, the probe-window is what you are looking for.

 

Norbert 

Norbert
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AristosQueue (NI)
NI Employee (retired)

Just open the front panel of your global. There's your watch window for it.

 

As for locals, creating a list of all the controls and indicators on the panels of all your VIs would be a gigantic list, and you'd have lots of confusing entries from reentrant Vis. I cannot imagine that there would be any value to such a display.

AmitKaria2k
Member

@Norbert:It depends on project and individual to use or not locals and / or globals. However, it is part and parcel of most of the project. For time being, lets assume that there are no locals or globals used in a project.

 

What I meant when I say "Locals" is to rather monitor the various indicator(s) on the Parent VI and it's child VI's using "Watch Variables" option which I'm suggesting. I want one solution for debugging either LabVIEW code (development system) or an executable file.

 

Yes, I'm kinda asking for a modified version of "Probes" window which rather than just monitoring a given wire monitor's the indicator variables on different VI's to show their current values.

 

@Aristos: I'll definitely consider your thought on monitoring re-entrant VI's. However, the proof-of-concept work that I'm on has assumptions that :

1. Monitor all VI's in memory that are running & display them as parent node in tree control.

2. Transverse in each VI's and populate their indicators as child items corresponding to each parent.

3. Give option to user to select the variable that needs to be watched

4. Once done, the selected watch variables will be displayed in a floating panel and will be read at very fast interval.

5. If above idea works (keeping fingers crossed) I can plan to implement breakpoints on value changed or similar events.

Norbert_B
Proven Zealot

Hm, i think you have get to get rid of the idea that LV has "variables".

The most famous sentence "The Wire Is The Variable" is true for most LV code. So, again, the Probe Windows already IS the variable watch window!

 

You know that you can distribute an arbitrary number of probes over an arbitrary number of VIs?

And if you want to stick to your "variable view of LV code", just think of the fact, that (if code is indeed LV), we only have local variables (aka "wire) and therefore, variables ("wires") are not shared between different VIs......

Norbert
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AmitKaria2k
Member

Yes, I do understand that wire is a variable, but instead of probing different instances of wires in a VI connected to an indicator (or its locals) in a VI, I would like to monitor the indicator value itself. It is useful especially when either the indicator(s) are hidden or you want to monitor the sub-vi indicator(s) in a single view. Again, probes are of no use when debugging an executable !

Norbert_B
Proven Zealot

@AmitKaria2k wrote:
[..]Again, probes are of no use when debugging an executable !

Hm, on my machine, probes for debuggable executables work just like during development. From the screenshot, i think you are using LV 2010, right? I am quite sure that this version also supports probes for debugging executables.

I think you should recap on Debugging Applications and Shared Libraries.

 

Norbert 

Norbert
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CEO: What exactly is stopping us from doing this?
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Marketing Manager: Just ignore it.
Darren
Proven Zealot
Status changed to: Declined

Any idea that has not received any kudos within a year after posting will be automatically declined.