why LabWindowsCVI whynot LabVIEW

[Kodeeswaran]

Why LabWindows why not LabVIEW. since i have been working on LabVIEW looking to shift my coding practices to CVI and Measurement Studio. Anybody knows pros and cons of these three. Can Anyone knows the resources location to learn CVI and Measurement Studio from Basic

[JonathanN]

Hi kodee,

Check out Wendy's post here which describes what types of things you need to consider when deciding between LabVIEW, LabWindows/CVI and even Measurement Studio. Her forum gives a good view on each product.

Best Regards,

[rorOttawa]

At work we have been using CVI for 20 years or so. Now there are sections of the company that preach Labview because it is "so easy" for non software programmers to create a test.

So to answer this call we produced a cvi program that calls a Labview function. NI has sample code that does this.

But to date I have seen nothing from this Labview group.

CVI Pro's:

- can easily import C code into CVI

- can easily design a GUI with callbacks to C code when you press a button on the GUI. 

- in our case we have a CVI sequencer(NI's old FREE Test Executive) that can look after test results and the executing of tests one after the other. 

- Using 'Full Development package" can install the software on many PC's at no additional cost.

- any C programmer can grasp quickly.

Labview Pro's:

- easy for non software programers to grasp.

- NI are pushing it.

- good for lab use where you want to put some sort of test together quickly.

Labview Con's:

- must use Test Stand as the sequencer to control the execution of several Labview tests.

- Test Stand always has a cost per PC.

- hard to visualize the program on computer screen because it is graphical and takes up a lot of screen space.

Very short list but as you see I am a CVI'r

[jr_2005]

I think you had one of the LabView characteristics in the wrong section: "- easy for non software programmers to grasp" surely should be a Con, not a Pro?

Half the problems I have in cleaning up other peoples code is because they think (incorrectly) they know how to write C - god knows what a mess a non-software engineer can make of a (apparantly much easier to produce) LabView program. Keep software for software programmers, I say!

JR

[rorOttawa]

10-4 but when managers see from an NI sales demo how easy it is to write the program. They see dollar signs.

Wow I can hire any idiot to write my code.....not.

[menchar]

I think it usually gets down to the fact that if the implementor views him or herself as a capable C programmer, he/she is going to want to implement in CVI rather than LabView.   As mentioned, the granularity is there to be more certain you can implement a solution, even though you may write a whole lot of code to do it rather than connecting icons with lines. 

If the workload is such that non-programmers have to do a lot of development, I'd say CVI is not the answer.  With C, the paradigm is "trust the programmer" not to do stupid things, and non-pro folks can't be trusted not to do genuinely stupid things in C.  They may well be intelligent professionals in their field, but that doesn't make them capable programmers.  Some of the most botched up code I've ever seen was done by system engineers / EE's who had read the first three chapters of K & R and declared themselves C programmers.   Poor programmers, and with no grasp of even the simplest design concepts, they hack out gobs of code that typically breaks at runtime because they've mishandled pointers/arrays.  But most of these can eventually learn to accept advice as to how to structure their code.

Worse are those who have taken a couple of programming courses at the local junior college and weasel their way onto projects and strive to make themselves indespensible.  Too stupid to be embarassed, they are unable to accept any guidance as to style or form.    I find they often form up into a "conspiracy of fools" to cover their mistakes, or ingratiate themselves with a scientist or engineer who can't code at all. 

I can't tell you how many times I've had the seniormost technical professional involved (usually an engineering fellow, tech director, or senior scientist) come to me to help unhose bungled CVI applications, often after the culprits shoved aside my participation in the first place.

On the other hand, the point to most systems isn't to have good code or a good software design.  The domain knowledge involved is almost always going to be held by non-software people.  Many want a sense of "doing something" as a day to day activity - and they often gravitate to coding if they can at all do this.  A pure C programmer isn't very useful, generally speaking - you have to work in some domain.

Of course, NI knows all of this, that's why they have both products.

Several groups I know of are now doing test SW impementations in C# and Visual Studio - sure, it's Microsoft proprietary, but intellegent non-software people are better able to implement using OO (and avoiding pointers and memory management).  I think NI's done what it can to approach the whole .NET thing. 

There are several threads on the website in re CVI Vs. LV.