Simon Kelly

You might want to use the 'openFP' and 'closeFP' VI methods (using an invoke node) instead since they give you more options and according to NI are the recommended method for opening and closing the front panel (see help file on VI methods).

Thanks for you reply Rolf. After much experimentation after my last post I discovered what you said about 'garbage collection' of refnums which is what has been happening. I think your idea of creating a deamon that runs in the background is a good one! For anyone interested, I have attached 3 very simple VI's to illustrate the problem. It uses a queue to communicate between 2 VI's. The queue's refnum is stored in a LV2 global. If the VI that first initialized the refnum is closed, then the other VI generates an error caused by the invalid refnum. I hope someone will find it useful. Download File:post-2342-1123839106.llb

Please find development distro here.... Download File:post-2342-1121413637.llb

I've been trying to write a module manager for an application i'm building. The idea is that the user decides what modules to run and then these modules are managed using the VI server. Their refernces are stored in an array and if the user wants to change what modules are running, then the module manger should shutdown or start the VI's. This seems to work fine if you place the manager VI on the block diagram of the calling VI but if you call the VI using the VI server then somehow the references to the running modules become invalid. I have attached a basic version of the system. If you run the 'CALL from diagram' VI the system works fine but if you run the 'CALL by reference' VI, it all goes horribly wrong. The reason I want to call by refernce is that I don't want the calling VI to have to wait until the user has decided what modules to run before it can continue. Please help, I don't know where to go from here. Download File:post-2342-1121338478.zip

Hmm, didn't notice that. I guess your only option then is what m3nth said

Or you could just add a simple error handler to the output of the Write to SGL file and set the dialog option to 'no dialog'. If you want you can even add a case structure that checks if the error is 43, if it is the error gets handled as above (ignored) and if it isn't then you can choose some other method to handle the error.

Is it possible to get rid of the 'save VI' dialog that pops up when you close a VI that has been changed. Let me explain. I have created a multi page application using templates but when you try to close a page the 'Save VI' dialog pops up because the instance of the template hasn't been saved yet. I could programmatically save the VI in a temp directory but I was wondering if there is a better way of doing it.