Formula node forbid to run VI when undefined variable is used

On all LabVIEW version, we can use Formula node to evaluate mathematical formulas.
We can define input and output variable freely and calculate using some variety of formula.
But when we use undefined variable as output, can execute VIs with no errors.
We think it is a problem because when programmer makes a typo, they cannot notice the mistake.
When undefined variable is used as output variable, LabVIEW should forbid to run VI.

I think you are going to get the same (or similar) answers than to my suggestion(s) to make VI outputs potentially "required" and the same for some functions (built-in VIs):
http://forums.ni.com/t5/LabVIEW-Idea-Exchange/Allow-required-outputs-in-VIs/idc-p/3157058
http://forums.ni.com/t5/LabVIEW-Idea-Exchange/quot-Function-terminal-not-connected-quot-detection-plus/idi-p/1858573
In general, I agree with you, there is a potential for problems. Not really for the reason you are mentioning, because a typo will break the VI (unless you have two output variables with very similar names - unlike in your example - such as y and y0). But it could make for some frustrating debugging session.

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    My laptop's FAN is running really fast and loudly when plugged in AC power source.
    However the FAN runs quietly when the battery is used.
    The laptop is new and so far only the antivirus application is running.
    Is this a normal behavior or an issue ?
    Normally a FAN run as fast when the CPU is hot and many applications are running.
    regards,

    Hi Yassine
    Dont be worried about this notebook behavior this is nothing unusual
    The reason why the fan is running faster when AC adaptor is connected this very simple: the Windows system use different settings using the battery or mains power.
    Using battery mode, the system is configured differently in order to save battery power and to increase notebook working time.
    You can change the settings in control panel -> power options.
    Here you will find different power plans
    Click on the current power plant and check the Change Advanced power settings.
    Here you would find the settings for cooling method (sometimes its placed within the Toshiba power saver or Processor power management).
    There you can change System cooling policy: you will choose either passive or active
    Maybe this FAQ could be interesting for you:
    http://aps2.toshiba-tro.de/kb0/HTD12017W0001R01.htm

  • HELP: Run-time array dimension in LabVIEW formula node

    I need to dimension an array at run time within a formula node as follows:
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    TIA,
    Hugh

    Can't you just use the Initialize Array function outside the formula node and pass that instead?

  • Why do I receive Error -23088 when using the Eval Formula Node.vi (LV6.1)?

    Hi,
    I want to evaluate formulas like x=v>20; with that vi. When typing the
    same formula into an normal Formula Node I get the correct answer. When
    changing the formula into x=v+20; the eval Formula node.vi works fine.
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    Thanks for your help,
    Daniel

    Joel A wrote:
    > I think the boolean (binary) ops are the only difference between the two nodes.&nbsp; I pulled this from the help:
    > Formula Node and Expression Node Functions
    >
    > The following list contains the names of the Formula Node and Expression Node functions, and their descriptions. Except for the binary functions, you also can use these functions with <a href="gmath.chm::/Parser_VIs.html" target="_blank">Formula VIs</a>. All function names must be lowercase. You also can use <a href="mk:@MSITStore:C:\Program%20Files\National%20Instruments\LabVIEW%208.0\help\lvhowto.chm::/Precedence_of_Operators_in.html" target="_blank">operators</a> and the pi constant in Formula and Expression Nodes.
    > Start at the help above, and see if you can find any helpful information.
    > &nbsp;
    > &nbsp;
    > J
    Thanks for help,
    I solved the problem by using the "Parse Arithmetic Expression.llb" from
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