hi everyone im new to labview i want to know that why boolen and boolen wires are breaking

[Leaner24]

[Bob_Schor]

Hello, @Leaner24.

     Despite having joined the LabVIEW Forum almost six months ago, you've had only two posts, and don't seem to have picked up the "preferred way to ask a question for help".

Suggestions for posting:

• Provide more complete detail in your Post.  All you have (besides the title) is a single picture, one we can only "look at" but can't edit or inspect closely.
• You provide no information on your LabVIEW experience.  You've clearly been "interested" for at least six months -- what have you been doing with LabVIEW?  Taking a class?  Reading books?  Watching Videos?
• You provide no information on your LabVIEW "environment".  What Operating System are you using?  What Version of LabVIEW (e.g. LabVIEW 2024 Q3, 32-bit) are you using (be sure to say if 32 or 64-bit).
• If you want help with LabVIEW code, then you need to provide us with the code so we can fully understand what it really does (as opposed to "what you want it to do").  This requires that you post one or more VIs that you've written.  But there's a problem -- you might be running a recent version of LabVIEW, and those of us (such as myself) who do this a lot are probably using older versions, like LabVIEW 2019 or 2021 (the two versions I use).  So if you are using LabVIEW 2022 or later, you need to open your VI, go to File, Save for Previous Version, and choose LabVIEW 2019 or 2021.  You might find that this process saves a lot more stuff than you want to post, but you can at least post your VI in a form we can open.

The following comments are about what I can see in your "picture of code":

• Particularly as a beginning, almost never use a Frame Sequence. LabVIEW "invented" the Error Line (which traditional goes in on the lower left connector and comes out on the lower right connector) to "serialize" sequential code execution.
• Your first Frame has a "naked" Event Structure (where is its surrounding While loop?  Do you understand the purpose of an Event Structure?  What other cases does it have that we can't "see" in the 2-D Image you show of a 3-D structure?).
• There are clearly other "Event Structure" cases, one of which is probably causing your problem.  Sorry I can't "peek" and verify this ...

Please attach some code capable of being opened in LabVIEW 2019 or 2021.

Bob Schor

[altenbach]

Your boolean wires that are broken are arrays and you wire them to terminal that cannot accept arrays, just scalars. You need to reduce it to a single boolean based on the desired functionality (all elements are true? some elements are true? no elements are true? etc.)

Your entire code stinkssmells  With pointless sequences, blatant overuse of local variables, potential race conditions and dangerous placement of the event structure. If the tab control should remain on page 1, disable it instead of hammering it back to page 1 three times in a row. If pages should only change programmatically, make the tab an indicator!

[Mikrobi74]

When you have a broken wire activate Context Help (Ctrl+H)  and place the cursor on the broken wire.

Context help will explain the issue.

[Yamaeda]

Select can't handle array inputs. 

[altenbach]

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@Yamaeda wrote:

Select can't handle array inputs. 

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Same for the case structure, of course.

Think about your problem. You have an array of usernames and an array of passwords. If a username exists, you will get an array of FALSE with one single TRUE. Same for the password. Then you AND these two boolean arrays and you will only get one single TRUE in the resulting array if both the username and password are in the same position. (If the user would enter the password of another user, both arrays would have a TRUE at different positions and the AND would result in an array of all FALSE). In your case, authentication only occurs if a TRUE exists after the AND, so an "OR array elements" would give you a boolean scalar that the select and case structure can handle.

[Yamaeda]

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@altenbach wrote:

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@Yamaeda wrote:

Select can't handle array inputs. 

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Same for the case structure, of course.

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Right. I didn't see that.