When I use Call Library Function Node in real time, is the DLL loaded once for all or load every time it is called?

[qing_shan61]

When I use Call Library Function Node in real time, is the DLL loaded once for all or load every time when it is called?

I have a time critical real time application, in which I use a piece of DLL function developed by C++.  It is OK?  Could any senior developer assure me?

Thank you in advance.

[Andrey_Dmitriev]

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@qing_shan61 wrote:

When I use Call Library Function Node in real time, is the DLL loaded once for all or load every time when it is called?

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Once

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@qing_shan61 wrote:

I have a time critical real time application, in which I use a piece of DLL function developed by C++.  It is OK?

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OK

Be sure that all DLL calls are thread safe (do not perform calls in UI thread).

Also for real-time application you need real-time OS.

Andrey.

[qing_shan61]

what is a UI thread? Andy

[smercurio_fc · Accepted solution]

The UI thread is the thread used to update the user interface. It's slow. And it's meant to be that way because humans are slow.

The Call Library Function Node can be configured as to what thread to use in the configuration dialog for it. Please review the LabVIEW documentation on how to do this.

[Boopathirajan]

Hi, if I call the same function in a dll once from a call library function out of while loop and next time onwards inside while loop using another call library function will it continue in the same dll function alredy opened outside the loop or will it create a new copy of dll function execution.

if I want to continue on the same dll function what should I do.

my first iteration is read file database and others are real time simulation program that uses the data read in first iteration.