How can i make 2 functions happen sequentially in a loop

[domcorrado]

Hello, i have a problem with this VI. I want to make the 2 subVIs happen one after another in the while loop: when the first one has finished the second one starts, and when it ends the loop starts again. I tried to come up with a solution with a case structure, making the second subVI as a condition for the result of the first one, but it doesnt really work: the second subVI only runs for a couple of seconds when the condition is respected, but since the first subVI runs from start , it stops running after a seconds. What could i do to make the two VIs run sequentially as i said?

Thank you

[LucianM · Accepted solution]

If your VIs have error cluster terminals wire them to set the order you want. If not, you can use a Flat Sequence Structure.

[GerdW · Accepted solution]

Hi,

---

@LucianM wrote:

If not, you can use a Flat Sequence Structure.

---

In that case you should rather make those subVIs to use errorIO to enable simple DATAFLOW…

[LucianM]

---

@GerdW wrote:

Hi,

---

@LucianM wrote:

If not, you can use a Flat Sequence Structure.

---

In that case you should rather make those subVIs to use errorIO to enable simple DATAFLOW…

---

Yes, if you can edit those subVIs.

[domcorrado]

I managed to do it with a flat sequence, gonna also try with the error i/o dataflow and see what fits my case more.

My only problem now is that i have all of this in a while loop to make it run repeatedly, but it just doesnt happen (only runs one time), any idea why?

[BEdby]

Hi

I think the problem is, that the second loop has a false constant wired to its stop condition. It runs endlessly.

If you make it a true constant it should work.

[domcorrado]

problem is, if i make it a true constant, the first subVI will start running again instantly, during the time the second subVI still runs, which i dont want to

[LucianM]

No, this is not true! VIs are executed one after the other. Use Highlight Execution to see better what's happening:

[johntrich1971]

---

@domcorrado wrote:

I managed to do it with a flat sequence, gonna also try with the error i/o dataflow and see what fits my case more.

My only problem now is that i have all of this in a while loop to make it run repeatedly, but it just doesnt happen (only runs one time), any idea why?

---

Having now seen your code I would suggest that you learn about state machines. With a state machine architecture you can accomplish this task with a single loop - no need for getting stuck inside of inner loops or finding ways to program around that. I've attached what that could look like with your example.