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Posts: 23

Has anyone successfully added new steps during a sequence execution?

Good morning,

I'm writing a LabView VI to add new steps during the execution of a sequence. I've found a few issues and need assistance. In LabView, I use an Engine.NewStep followed by a Sequence.InsertStep.

Issue #1:

I run my sequence using "Test UUTs" or "Single Pass" in the sequence editor. If I have breakpoints set, the sequence works just fine. My new steps appear in the Steps tab and they appear in the report once the sequence is done.

If I remove all breakpoints, I get the following message during the execution:

"Invalid step index '16' for 'Main' phase in sequence 'MainSequence'. Error Code: -17301, Index out of range."

As a workaround, I have inserted an Exe
cution.Break at the beginning of my VI. I get no errors in the sequence editor when I do this. The problem with this is my execution is paused in the sequence editor once the VI completes. The execution remains paused even if I include an Execution.Resume at the end of my VI. I want the sequence to run all the way through without pausing. Any suggestions?

Issue #2

As I add steps during the execution, I have been using the None adapter. If I use the LabVIEW or CVI adapters, can I programmatically specify the module that I want to use? As a workaround, I might try cloning existing steps, but I'd much prefer to create all my steps from scratch.

I'm writing a system test for a highly configurable multiplexer, so it's important that I can reconfigure my sequence as it runs. Has anyone else tried to do this?


Chris Norris
Carrier Access Corp.
(303) 218-5826
Active Participant
Posts: 270

Re: Has anyone successfully added new steps during a sequence execution?

It is not really safe to add/delete steps to an executing sequence. Instead what you can try is to create a sequence on the fly with the steps that you need, and then run it as a subsequence. In TestStand 2.0, there is an example that does this and it's actually pretty straightforward. The example is called "Sequence Builder Tool" and it creates and runs a sequence on the fly by adding steps from a template.


Azucena Perez
Trusted Enthusiast
Posts: 4,666

Re: Has anyone successfully added new steps during a sequence execution?


File attached is a demo sequence with a VI step.
This creates a step in the main of Numeric Limits Type using the None Adaptor.

I have run it using the process model and get no errors.

Have a go

Ray Farmer