Mixed Signal Graph Modifies VI Unintentionally?

[aschipfl]

A VI containing a Mixed Signal Graph on its front panel might be marked as modified every time it is opened:

Create a new VI, place a Mixed Signal Graph, wire a cluster containing an analog and a digital waveform into it, save the VI and close it. After re-opening the VI, it is marked as modified (the asterisk * appears in the title bar).

I encountered this behaviour only when a mixture of analog signals (arrays of doubles or analog waveforms) and digital signals (digital table or digital waveforms) is wired (clusters of arrays of ...).

I use LabVIEW 2013 (version 13.0f3 64-bit).

[James.M]

That's weird.

I would assume it has something to do with the way the graph is saved to file. Maybe it saves to file as a general mixed signal graph and doesn't know what type of data until it's done loading the block diagram. Then that change in the VI once it loads the BD makes LabVIEW think there's a different bit somewhere. This is all speculation.

I can get the star not to show up when loaded if I don't write the digital waveform along with the analog, but it takes two saves for it to stick.

[aschipfl]

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@James.M wrote:

[...] I can get the star not to show up when loaded if I don't write the digital waveform along with the analog, but it takes two saves for it to stick.

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 Hi James,

I cannot follow your statement, sorry; what do you mean exactly? Are you talking about (not) writing any data into the graph? Please explain.

Thanks!

[James.M]

• Take this:

 

• Save and reopen. There's a star.
• Edit it to be this:

• Save and reopen. There will be a star!
• Save and Reopen again without changing anything, star is gone! 

[aschipfl]

Hi James,

it behaves the same for me using LabVIEW 2013 (when "output cluster" is the graph).

This is not a solution however, as the final version of the VI does not route the desired data to the graph; but quite interesting though...

[James.M]

Oh, yeah it wasn't meant as a solution, just an interesting occurrence.

[aschipfl]

I just found out another interesting thing about that issue:

When the Mixed Signal Graph is placed in a Page of a Tab Control that is not the default page, the modification * does not appear when the VI is loaded but as soon as the Tab containing the graph is selected.