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Missing Assignment to Tunnel



I am running an example vi for my mass flow controller (attached). The VI works fine but issue is when I connect a write to file block to the waveform output, I only get two of the process information signals plus the setpoint recorded in my file. Looking at the block diagram of the VI, I presume that this is because only two the signals were passed to the scan from string block in the case structure. So what I am trying to do here is to pass additional strings (trying with just (String array [2] for now) to the scan from string block that I have now included and then connect it to the merge signals block. But once I do that and run the code I get the missing alignment to tunnel error. Suggestions to rectify will be appreciated


If there are better alternatives to get all the process information recorded at any given instant from my instrument to excel when I run the VI, please let me know. 




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Message 1 of 3

Thank you for attaching your VI.  However, many long-time users of LabVIEW (and frequent contributors to this Forum) do not upgrade every year, so cannot examine code written with LabVIEW 2023.  Please "Save for Previous Version", specifying, say, LabVIEW 2019 or LabVIEW 2021 (the earlier date will get more "looks").


Bob Schor

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You failed to attach your subVIs (e.g. Read process information...)


You have one tunnel that breaks your VI because it is not wired in the TRUE case and NOT set to "use default if unwired". (Do that for all your tunnels and you don't even need to wire the other zeroes).





There are very basic problems. I recommend the learning resources listed at the top of the forum.


  • We don't really know the conventions, e.g. how these strings look like?
  • Looking at the string length (>5) for the "Error Text" output to make boolean decisions seems fragile.
  • You should use local variables instead of value property nodes to write to controls (e.g. valve mode)


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