Parameters when running sequence in NewExecution

[TiWi]

Hi,
I was wondering how to specify the parameters of a sequence when using the sequence callback step in a new execution. The only parameter I have is the sequence name ("MainSequence") to pass to the called sequence, altough the MainSequence has 3 other parameters.

Thanks,

Louis

[TiWi]

To clarify things, I am calling a sequence using the new execution sequence callback. The sequence that I want to call has 3 parameters. Now, how do I assing the values for those parameters in the sequence callback step?

Thanks!

[RayFarmer]

Hi,

This mean in the Specify Sequence Call Dialog, you have set the control for New Execution?

If this is the case you just specify you parameter values in the Parameters control on that Dialog. So you should see your three parameters listed in the Parameters control. select each parameter an enter the expression that matches your values you wish to pass the the sequence.

I hope I have understand you correctly.

Regards
Ray Farmer

[TiWi]

Yes I am using the New Execution, but I have problem specifying the entry point. I want to run the "MainSequence". When I specify that for the entry point, there are no parameters listed, so I guess that not the way to do it. Otherwise, if I specify "Single Pass", I only have 1 parameter available, the sequence name I want to run (i.e. "MainSequence").

[RayFarmer]

Hi,

To call it using the process model entry point you would have to call it as a SequenceCall step from within MainSequence. Therefore it cannot be called MainSequence

Otherwise, you will have to modify the Process Model sequence.
You could make a new Entry Point to handle your different MainSequence requirement.

Regards
Ray Farmer

[TiWi]

I've changed the process model to the actual sequence I am calling and it seems to be working... but I don't think it's the right way to do it. Is there an alternative to using the process model entry point? There must be a simple way to call a sequence in a new execution and specify it's parameters value.

I am experiencing with this because I am trying to solve a bug I have with a LabWindows DLL. I believe that it is preventing me to run the DLL twice at the same time because of some multithreading protection in LabWindows. In TestStand, is it possible to load a DLL twice in memory to have two separate executions and therefore avoid any multithreading problem?

Thanks!

[James_Grey]

a) To directly call a subsequence in a new execution without using a process model entry point, click the settings button and set the Process Model Option to Do not use a process model. Your parameters will appear as usual.

b) As far a dll behavior goes, calling a module in multiple executions is not going to be any different that calling it from multiple threads in the same execution.

[TiWi]

Is there a way to avoid any multithreading problem when calling a dll adapter from TestStand?

[dug9000]

Tiwi,

I read your other post about your telnet issue, and I recommend you post to the CVI forum asking if there is a way to do what you are trying to do from multiple threads in parallel. This does not sound like a teststand issue. If you are calling into your dll from multiple testand threads, then the code in your dll function is being executed in parallel. The cvi function you are calling however, might not be reentrant (reentrant means able to be called by multiple threads in parallel) so it is making one of your threads block until the other completes. I suspect there is a different way to do what you are trying to do that will not have this problem, but I think the changes that you will need to make will be in the dll and not on the teststand side. I recommend you post to the CVI group and explain what you are trying to accomplish and see if they have a solution for you.

Hope this helps,
-Doug

[Tyler T.]

For other readers, this post explains why the CVI DLL cannot be called from multiple processes:

http://forums.ni.com/ni/board/message?board.id=180&message.id=16687

As Doug pointed out, there is no setting that we can switch to make it so that the called DLL is reentrant.

Tyler T.
Applications Engineer
National Instruments