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Member
Huntian
Posts: 3
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To find for a flow chart

Dear engineers,
Who can offer me the flow chart for the VI:Analyze-Signal Processing VIS-Signal Generations VIS-Binary MLS.VI? Without the flow chart,I can't understand the block diagram of Binary MLS.VI in LabVIEW 7.0Express.
Thanks in advance.Looking forward to your reply!
Knight of NI
Knight of NI
tst
Posts: 10,704

Re: To find for a flow chart

You can see the VI's diagram simply by placing it on the block diagram and double clicking it.
A better way to understand is to click ctrl+H or the yellow question mark near the VI icon. That will popup a help window which will give you the description for the VI.

To learn more, I suggest you read the LabVIEW user manual. Also, try searching this site and google for LabVIEW tutorials. Here is one you can start with and here is another. You can also contact your local NI office and join one of their courses.
In addition, I suggest you read the LabVIEW style guide.

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Member
Huntian
Posts: 3

Re: To find for a flow chart

Dear Veteran,
Thank you all the same.
In fact,I had read the block diagram of the VI.But I still can't understand the principles in it.So I
seach the original flow chart for it,not the graphical program one.
I wonder if you can tell me where to find.



Huntian,
Regards
Knight of NI
Knight of NI
tst
Posts: 10,704

Re: To find for a flow chart

The VI was written by NI, and they're not in a habit of releasing their VIs (at least the ones which aren't examples) with many comments, nor do they release their internal papers, so I don't think you will be able to find any additional data, unless someone has specifically analyzed that VI. In fact, I'm not even sure that there ever was a flowchart for this algorithm.
The first thing you need to think about is whether you really need to understand HOW it works. You have the description for it, which tells you what it does, which should be enough for using it.
Since the VI is fairly simple, and you have its code, and you know exactly what it's supposed to do, you can draw a flowchart or write an algorithm based on the code.
The principles you will need to understand to do this are the mask, uninitialized shift registers, logical shifts and what happens when you AND numbers. These could be understood by playing around with them and by reading the documentation. Unfortunately, this isn't stuff I really deal with myself, so I can't help you understand the VI without going over this stuff first.

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Knight of NI
Knight of NI
Ben
Posts: 16,102

Re: To find for a flow chart

Let me exapand on tst's comments.

Flow charts are seldom used with LabVIEW.

LabVIEW's programing consturcts (For Loop, While Loop, Sequence structure, etc) are composed of multiple Flow Diagram elements.

Asking for a flow diagram of a LV diagram is like asking for the illustrated parts break down of a automobile when you want to learn how to drive it. What you really would need in that case would be the user manual.

The closest thing to an "Owners Manual" of a LV diagram is the VI documentation that tst mentioned.

Another possiblity would be the "State Diagram" if the code was developed from a State Diagram.

Aside from two examples, I have never seen any code from NI that used a SD.

Now back to helping you....

The details of the diagram operators used in the VI you want to understand can be learned by reading the help text for the operators themselves.

To better understand how they are bieng used together, I suggest using "Execution Highlighting" (light buld mode).

Watch the code in execution highlighting. You can single step if the diagram is moving too fast. If you want to track what is happening to the data as it executes, probe the wires that are involved in the action.

Once you have become familiar with the diagram objects and the dat flow paradym, you will find that LV diagrams (when properly written) are in themselves an illustration of what they do.

In many regards they are superior to flow diagrams because it is easier "ingore the the trees to appreciate the forest".

Ben

Side note:

Durring kick-off meetings my boss will get up and take a break (sorta like a band before a drum solo starts) when he hears me start my lecture on how flow diagrams are not that useful in LV, blah, blah, blah and we will develop State Diagrams instead.
Ben Rayner
Who is NOT John Galt... yet... just building Rayner's Ridge

Member
Huntian
Posts: 3
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Re: To find for a flow chart

Flow chart,State diagram,Block code diagram,and so on ,I learn something from all of you.
Maybe single step highlighting execution is a good way to solve my problem.Let me try.

Thsnks for your immediate replies.