execution problem in VI server

[EricMgNiBh]

Hi 

I am using Pxie4330, and I try to use VI server just to test some Data Acquisition from strain gauge . the SubVi works well but the host program ( main program ) which I called the sub vi by reference in that, executes incompletely. I really can't figure it out the problem. I have attached the photo , it shows that open application reference works well, vi server works well but  call by reference does not executes and does not display the graph ?

plz help

Thanks  

[Mark_Yedinak]

It won't display the graph until the subVI completes executing. LabVIEW is a data flow language and the data from a node (subVI) will not be available until it completes executing.

[EricMgNiBh]

Hi 

Thanks for your fast response. 

I understand but what can I do in this situation ? I run the main VI and automatically subvi start running. if it does not show the result at the same time why people call the labview real time ? now I confused what is the purpose of Vi server. 

[EricMgNiBh]

BTW I can't stop the subvi when I run my main , it will show some error which make sense. 

[Mark_Yedinak]

You need to provide more information. What eror are you getting?

You need to understand the basics of how data flow languages work. If you want to run a subVI in the background you should use the Start Asychronous Call to start the subVI. To pass information from the subVI to the main application you can use a queue, notifier or user events.  Also, no program running on a PC running WIndows, Mac or Linux will not be real time. None of these operating systems are deterministic. Real time means code execution is deterministic.

[EricMgNiBh]

Hi , 

I will not get any error. as the picture shows call by reference does not pass the data to indicator. then how can I use start Asychronous call to start sub vi ? so basically I need to study user events for this application ? 

thanks 

[Mark_Yedinak]

I would recommend that you look at the examples that ship with LabVIEW for teh Start Asychronous Call, queues, notifiers and user events. You may also want to go through the online tutorials.