retrieve iteration from stacked sequence structure

[Synbios]

I have a stacked sequence structure with 15 iterations. Is there a functional equivalent to the "i" from the For loop or a way to make one?

I need to trigger some other events based on what iteration of the stacked sequence is running. 

[johnsold]

In a sequence structure they are called frames rather than iterations.  And you have run into one of the reasons why sequence structures are usually not the best arrchitecture for involved programs: They are hard to modify and essentially impossible to branch.

You can context-click on the edge of the frame and choose Replace with Case Structure.  Enclose the case structure in a while loop.  With just a little extra effort you will have a state machine which is much more flexible.

Lynn

[tgif73]

Hi,

you can put numeric value 0 to case 0, then pass that value + 1 to next stack (right click the sequence structure, add sequence local). It would be better design to use state machine than sequence structure.

[RTSLVU]

Let me first reiterate what the others have said. Avoid stacked sequences like the plague!

I have found that except for very few situations there is always a better way then using a sequence structure.

That being said you could use a local variable to do this too...

[Synbios]

I've convinced myself it's better to use a proper state machine.

So to do this, the best method is to have 15 serparate case structures, and place that into a while loop with N=15?

..then read the iteration number, and depending on that logic, select the proper case structure within the while loop?

[nathand]

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@Synbios wrote:

I've convinced myself it's better to use a proper state machine.

So to do this, the best method is to have 15 serparate case structures, and place that into a while loop with N=15?

..then read the iteration number, and depending on that logic, select the proper case structure within the while loop?

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That should be ONE case structure, containing 15 different cases.  Then you wire the iteration number directly to the ? terminal of the case structure.

[Synbios]

That makes sense. thanks!

[smercurio_fc]

May I humbly suggest this article: Application Design Patterns: State Machines

You can create a state machine using the VI template that ships with LabVIEW. File -> New... Then expand the "From Template" branch.

[Synbios]

In your example though, how do you get the dark bolded local variables? Or the part of the first frame that says I32 Iteration.

[smercurio_fc]

They're drawn that way automatically my setting the local variable to "read". With the addition of the little arrows (as a consequence of an idea submitted in the LabVIEW Idea Exchange) it's somewhat redundant now.