Darren's Weekly Nugget 06/19/2006

Question

Have you noticed the new "Call Setup..." menu option when right-clicking subVIs in LabVIEW 8.0?  It's a really handy way to clean up your diagrams, and improve the load times of your VIs:
The code in the two frames is functionally equivalent.  In the second frame, I simply dropped the subVI on my diagram, right-clicked and chose Call Setup.  Then I selected "Reload on each call".  That makes the code function the same as doing an Open/Call By Reference/Close, like in the top diagram.  If I had selected "Load and retain on first call", the VI would be loaded into memory the first time it is called, but its reference would be kept in memory if the code is ever called again (like if this frame was in a loop).  If I had selected "Load with callers (like subVI)", it would behave exactly like a normal subVI (and the little "Call By Reference" halo around the VI would be removed).
So in this example, we are using Call Setup primarily to clean up our diagram, since both frames do exactly the same thing.  But there are some cases where it can improve performance as well.  One example where I have used Call Setup is in the VI Analyzer 1.1.  The subVI we use to load a configuration file in the VI Analyzer is rather large (with hundreds of subVIs).  In VI Analyzer 1.0, this subVI was called statically, meaning whenever you launch the VI Analyzer from the menus, this VI (along with everything else in the VI Analyzer) had to be loaded into memory.  In VI Analyzer 1.1, we used Call Setup on the file loading VI and selected "Load and retain on first call".  This improved the VI Analyzer launch time quite a bit, since now we only load the file loading VI into memory if the user needs to load a VI Analyzer configuration file.  In other words, with version 1.1, the waiting time it takes to load the file loading VI is only experienced by users who need to load a configuration file...with 1.0, everybody had to wait.
-D
P.S. - Check out past nuggets here.
Message Edited by Darren on 06-19-2006 12:38 PM
Darren Nattinger, CLA
LabVIEW Artisan and Nugget Penman
Attachments:
Call_Setup.jpg ‏149 KB

Answer 1

Hello Darren, i have a major problem with the call setup.
You mentioned that there are no more problems when the connector pane changes, well i couldn't figure that one out.
I have a large Application where i use a lot of the call setups when i made some chenges in the connector pattern i never get an error message.
When i build the exe file there is no error message coming up during the build process, it only comes up when the programm reaches the call and the error message only says :
Error 1031 occurred at Call By Reference Node in Untitled 1
Possible reason(s):
LabVIEW:  VI Reference type does not match VI connector pane.
With this kind of error message i can't even find out which Vi the error caused,
so i have to check each call setup in the VI.
This is even worse then in the old style, because if you had an error there you also saw which VI it caused.
So what possibility is there to make a general test of all VIs loaded with a call setup?
It seems to me that with the call setup the connector pane is picked once when you create a call setup from the normal vi,
and it only updates the connector pane when you do again your right click and set the call setup again.
why does it not normaly update the actual connector pane???
I also didn't understand that in the LV 7.x Version. because there was the same problem with the conector pane.
Why isnt there a possibility to auto update the connnector pane????
Greetings Daniel