Set Steps parameters default value permanently

[Raf@Tecnora]

Using the following expression in a statement Step:

RunState.SequenceFile.Data.FileGlobalDefaults.mynum = 7,
RunState.SequenceFile.ChangeCount++

I am able to change the default value of a FileGlobal variable during sequence execution so I can retain it by saving the sequence file afterwards.

I would like to do the same for Steps parameters.

In a custom StepType coded in LabVIEW I can set Step parameters with the TS API:

Is it possible to do the same with a Step pre or post expression?

For instance, when I set the following post-expression in a PopUp step:

ThisContext.AsPropertyObject.SetValString("step.TitleExpr",1,"\"MyTitle\""),
RunState.SequenceFile.ChangeCount++

the parameter value changes at runtime, but when sequence ends the new value is not retained.

Thanks for reading

Raffaello

[Scott_Richardson]

I assume that "TitleExpr" is a custom property that you added to a step type

When TestStand runs a sequence it creates a run-time copy of a sequence so that changes to steps and most of their step properties (built-in and custom) do NOT affect the edit-time copy of the sequence in the sequence file in memory. This allows a sequence to be run in multiple executions or threads without stomping on each other. The one exception to run-time copies of built-in step properties is "TS" property, which is shared between the edit-time copy and any run-time copies, so any changes to RunState.Step.TS will affect the file in memory. This is not copied to conserve memory. You can only access the edit-time copy of a step using the context and this type of lookup path:
    "RunState.SequenceFile.Data.Seq["MainSequence"].Main["YourStepNameOrIndex"]..."

Here is a topic that lightly touches on what is copied at run-time: https://www.ni.com/docs/en-US/bundle/teststand/page/executions.html 

Hope that helps.