CLD-R Questions

[ColinCR]

A few CLD-R questions I'd like opinions on:

19. A copy of the Front Panel data, such as controls and indicators, is kept in memory during which one of the following cases?
1) The front panel of the subVI is open
2) The subVI has been changed but not saved
3) The panel uses data printing
4) The subVI uses local variables

What is data printing? I cannot find reference to this feature. 

32. You are given the following code to dynamically launch a dialog:

The dialog VI has the following VI Property settings:
-Show front panel when called = True
-Close afterwards if originally closed = True
-Run when opened = False
Given that the dialog VI exists, the run arrow is not broken, and no other instances of the VI are in memory, which of the following statements is true after the launcher code executes?
a. The Run VI Method starts execution of the dialog VI. The front panel of the dialog VI is not loaded into memory
b. The Run VI Method starts execution of the dialog VI. The front panel of the dialog VI opens and runs independently of the launcher code
c. The Open VI Reference starts execution of the dialog VI. The front panel of the dialog VI opens and runs independently of the launcher code
d. The Open VI Reference starts execution of the dialog VI. The front panel of the dialog VI is not loaded into memory

Answer is A. Please explain?

Thanks.

[crossrulz]

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@ColinCR wrote:

19. A copy of the Front Panel data, such as controls and indicators, is kept in memory during which one of the following cases?

What is data printing? I cannot find reference to this feature.

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I never heard of it either.  But the answer is obviously A.

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@ColinCR wrote:

32. You are given the following code to dynamically launch a dialog:

Answer is A. Please explain?

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I would think B myself.  If I had a little more time right now, I would build up the VIs to test it.

[ColinCR]

19. While I also would agree, the practice exam lists the answer (from the choices I did not list) as A - all of the above: 

a. All of the above
b. 1, 2 and 3
c. 1 and 2
d. 1

32. I also agree and chose B. I have no idea how A could be correct.

[ColinCR]

19 just has to be a typo. There is no other explanation. Person who wrote it meant to say the first choice is correct, and instead selected the first (All of the above) selection.

[ColinCR]

I stand corrected. From here: 

https://zone.ni.com/reference/en-XX/help/371361H-01/lvconcepts/vi_memory_usage/

With subVIs, you can use controls and indicators as inputs and outputs. The execution system makes a copy of the control and indicator data of the subVI in the following conditions:

• The front panel is in memory. This can occur for any of the following reasons:
  • The front panel is open.
  • The VI has been changed but not saved (all components of the VI remain in memory until the VI is saved).
• The panel uses data printing.
• The block diagram uses Property Nodes.
• The VI uses local variables.
• The panel uses data logging.
• A control uses suspend data range checking.

[JÞB]

I hate to be the one to mention it but, you need to read the Help for Run VI Method

Since the method ignores a lot of FP.x properties (notably: the show FP when called property) B is just there to test your knowledge of the differences between "Calling" a vi and involking the Run Method.  A common programmer error!  

Spoiler

You wouldn't believe how many times I've caught developers confused by that distintion "In-The-Wild"

[nanocyte]

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@ColinCR wrote:

A few CLD-R questions I'd like opinions on:

19. A copy of the Front Panel data, such as controls and indicators, is kept in memory during which one of the following cases?
1) The front panel of the subVI is open
2) The subVI has been changed but not saved
3) The panel uses data printing
4) The subVI uses local variables

What is data printing? I cannot find reference to this feature. 

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A local variable doesn't cause a copy of the whole front panel, it only makes a copy of the control that has the local. The answer is therefore B.

[JÞB]

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@nanocyte wrote:

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@ColinCR wrote:

A few CLD-R questions I'd like opinions on:

19. A copy of the Front Panel data, such as controls and indicators, is kept in memory during which one of the following cases?
1) The front panel of the subVI is open
2) The subVI has been changed but not saved
3) The panel uses data printing
4) The subVI uses local variables

What is data printing? I cannot find reference to this feature. 

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A local variable doesn't cause a copy of the whole front panel, it only makes a copy of the control that has the local. The answer is therefore B.

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Which becomes very obvious when you need to set the config parameter for max undo steps back to the old default (9) rather than the current default (99).  Now, tell me why...........

And for the rest,

Ctrl+I  Print Options  Print with execution.  Or take a gander at the Properties of 

Class>>VI Server >>Application>>Printing............  No one uses it but, it is there!

[ColinCR]

Great job resurrecting a dead thread on its second birthday! 

[Hooovahh]

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@JÞB wrote:

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@nanocyte

Class>>VI Server >>Application>>Printing............  No one uses it but, it is there!

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I used it several times before scripting was a thing.  I didn't have any other way to programatically get images of source code to be put into a document for archival or review.  I also had LabVIEW code in my senior thesis in college and I used it then to get images of the block diagram without having to open every VI and Print screen.

But Jeff is right, it was never a feature used very often.