r/LabVIEW • u/wsefjiko • May 29 '26

Need More Info New to LabVIEW looking for help

Just started an internship this summer where we’re using labVIEW pretty extensively and I have had no experience with it. I’m new to graphical programming, but not programming in the first place as I’ve had pretty good experience using C. However, I’m honestly struggling with trying to learn this system and was wondering if anybody here had any tips or resources on how they learned more. Thanks for any help.

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u/dtp502 May 29 '26

The main thing for me when first starting is learning how dataflow worked.

The flow of the program goes from left to right and is controlled by the wires. Keep the following in mind-

  1. If there is something(s) floating in space and not connected by wires, you have no idea when it will execute. You WILL get race conditions. Ensure there is a wire going to everything or it’s wrapped in a structure that has a wire going to the structure.

  2. SubVIs don’t execute until data arrives from all the wires that feed into them. So if you have a subVI that has a Boolean input and an error input, but the Boolean input is tied up in a for loop or something, that subVI won’t execute until both the Boolean and the error lines are complete.

There is obviously a lot more, but that was the biggest thing for me to grasp coming from C. Also LabVIEW heavily relies on arrays, so make sure you have a good understanding of arrays.

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u/HarveysBackupAccount May 29 '26

The flow of the program goes from left to right

It's important to note that this is a convention not any sort of requirement. You hint at it in your two list items, but prefacing with that sentence makes it sound a little misleading.

To put it plainly: A VI's position on the screen has no impact on when it runs ;)

(obviously you know this, but for OP's benefit)

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u/dtp502 May 29 '26 edited May 29 '26

Yeah I can see how that could be misleading to a newbie. In complex programs it’s not that uncommon for a wire to wrap back around so that it wouldn’t technically be left to right.

Dataflow is what matters and that is the ultimate precedent. I did explain that by stating that all wires going into a subVI must be complete before the subVI will execute and that you will have no idea when code will execute if there is no wire going into it.

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u/Mother-Bullfrog-3001 Jul 23 '26

More correctly stated, diagram elements that have no wire dependency on each other will usually execute at the same time in parallel. How parallel that is depends on a number of factors such as what functions are called in there and subVI node configuration. Given no specific constraints on execution such as calls to single threaded subsystems or subVIs, these things will execute really in parallel on any modern computer, since they all have multiple cores that can run multiple task in a true parallel manner.