Non enterrant on a single core machine

[Fresenius_Medical_Care]

Hi,

I had a very similar question in my CLA-R exam which kind of perplexed me a lot.

Imagine we have a single-core machine and we have an application running 3 VIs (Control, Communicate and Log) in separate parallel loops.

Control is set to high priority, Communicate to above normal and Log is set to Normal priority.

Control and Log use the same non-reentrant VI which takes a long time to execute. Its not possible to complete all operation in one loop period.

In such a scenario Which of these VIs (Control, Communicate and Log) will get more processor time and finish late less often?

[billko]

Are you asking every question on the CLA-R?

[Fresenius_Medical_Care]

Nope, not every question.

Just the ones which I feel have multiple answers.

May be the CLA Gurus here have a more clear perspective on the questions.

Do you have any insights on this Bill?

[rolfk]

With this wording it would be the Communication loop. It’s not mentioned that it’s subVI(s) always finish late. Extra stinkers: The Log loop will almost never run if at all since the first loop always gets the cookies first. 😀

Even if the Communication loop had VIs too that take longer than its loop time it still won’t have to arbitrate forthose subVIs and can go right at it again despite having finished late.

Overall, the problem is ill defined and with to many unknowns to make a fully qualified statement though.

[wiebe@CARYA]

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@Fresenius_Medical_Care wrote:

Control and Log use the same non-reentrant VI which takes a long time to execute. Its not possible to complete all operation in one loop period.

In such a scenario Which of these VIs (Control, Communicate and Log) will get more processor time and finish late less often?

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The time a VI takes doesn't say anything about it's CPU usage.

If the non-reentrant subVI as any kind of wait in it, it could take long to execute (and block the other loop) while consuming 0% CPU.

@Fresenius_Medical_Care wrote:

Just the ones which I feel have multiple answers.

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 They all have multiple answers (multiple choice 😁)... 

I failed a CLA-R ~ a decade ago. Every question got 10 lines of comment from me, explaining how each answers could be correct under conditions (that weren't given). I didn't have time enough to comment all questions (~20 about scripting lvproj's 🙄).

[JÞB]

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@Fresenius_Medical_Care wrote:

Nope, not every question.

Just the ones which I feel have multiple answers.

May be the CLA Gurus here have a more clear perspective on the questions.

Do you have any insights on this Bill?

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Ah Ha. Finally a question that make some sense and states your objective (Pass the written CLA-R exam)

The prep material tells you exactly what concepts will be covered and at what percentage of the test will cover each concept.  You know it's a 40 question test and I'll clue you in that the concepts are covered in order as they appear in the prep guide.  Therefore you know EXACTLY what concept each question is testing.  Knowing what concept is under test allows you to focus your responses to the subject matter of concern and avoid choosing irrelevant distractors. 

As you prepare,  READ the LabVIEW Help file on the concepts that you will have your knowledge tested on.  There are also Knowledge Base articles online at NI.com that detail advanced concepts.   And, of course, many of the questions are similar to one's you will find in the LabVIEW training material. 

As a CLA, you must have taken advantage of the online training program and required all of your development team members to have Training and Certification objectives in their professional development plans that feed into their annual performance reviews, RIGHT?

So, developing a focus on the concepts will keep you from having to memorize minutae that no CLA should ever encounter.   TO WIT: why in God's good name, did the team allow code review to pass when the control loop and Logging loop duplicate a long process?  Insanity!

[Fresenius_Medical_Care]

hi Jay,

I am exactly that for the 30 Questions on CLA-R.

But somehow I have lost $600 failing it 6 times so far.

Tomorrow is my last attempt and then am done. Will miss being a CLA after 8 years holding the cert.

On your suggestion of certification by points, sadly I may not be able to do that. 

My team constitutes of software engineers working mostly with Python and C while others are EE and drafters. I dont have any engineer attempting certification with NI under me.

So, exam is the only resort and I am so confused with many questions on it.

Thanks again for all the suggestions. I will be posting few more questions between now and tomorrow morning.

Will appreciate your feedback on some.

Thanks!

[billko]

Boy, these questions are quite daunting, and I can see why you would like help and/or opinions on them.  Unfortunately these are questions I cannot help you with.  😞

[wiebe@CARYA]

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@Fresenius_Medical_Care wrote:

So, exam is the only resort and I am so confused with many questions on it.

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The real exam is always an option...