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Labview runs in front of dialog box from third party .exe -> cannot simulate keyboard input



I need to use an external software to set some parameters of an actuator. When I run this software from Labview (using System Exec.VI) it opens a screen while loading and then a dialog box. I need to select something from this dialog box (I am using a keyboard simulator). But just after the dialog box appears, Labview's window comes in front of it and then all the keyboard commands end up in the Labview's window instead of the external dialog box.


Has anyone ever had a similar problem? I have been looking aroung and I could not find a solution. I cannot use the ALT+TAB or anything like that because dialog boxes do not appear there (something of "modal" and "non-modal" windows).

I came up with a very unreliable solution by chance: If I hit (actually simulate) one key while the loading screen is on and before the dialog box appears, then the dialog box stays upfront. I think it is like telling the Labview "do not come to the front, I want to stay working in this other window". I do not trust this temporary solution at all but maybe it triggers an idea for a solution.


Please see the attached image: After I hit the RUN button, my exe is called and the "loading" screen is displayed on front. Then, the dialog box is left behind the Labview interface.

Dialog Box in the back.png


Any ideas are welcome!!





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Why not just write some LV code to configure the actuator and take the external software completely out of the picture.

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Actually I am using that to control the actuator but I also need to configure one specific parameter in the memory. The documentation is not very clear about how to access that parameter. I should write directly in the EEPROM of the controller and I am afraid that if a miss the exact direction I might overwrite something that would turn my expensive machine in a pile of metal.

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Can you post the make and model of the actuator?

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Here it is: SCN6-050-100AB-NA from Dyadic Systems Co. It is a very nice actuator (quite cheap too!). A C library can be downloaded to use the basic functions; they also have (free) software of their own to program it.


Anyway, I do not really have the time to understand how to program the memory and then develop the programming functions in Labview (I gave it a try for a couple of days). The machine needs to be running soon. This is why I rather rely on the Manufacture's software and get this working fast. Any ideas on the dialog box thing?

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Did a little digging and I don't have any ideas about controlling the focus of the dialog.  I was also unable to find any docs for communication with the actuator.  Can you post what you have?


One way to figure out the EE write is to install Portmon and monitor what goes on between the factory software and the actuator.  If I were to create a LV vi to write to the EE, I would also write a vi that could read the EE so I could verify that the write occured correctly. 

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Hi Wayne,


I believe it is a good idea to use Portmon, I will give it a try hopefully today. 


I have attached the two manuals that can be downloaded from the actuator's webpage ( Then I have attached the manual of the software (I cannot attached the software because they sell it); check on page 24: CTA-1EX, that's the software I am using. 


Isn't it weird that there is little info about the dialog box thing? I would have thought that many people had this issue.


Thanks for the help! 




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