I've got a dll library that I need to interface with. One of the critical interfaces to it is the interrupt driven messaging from it. This is implemented with register and unregister calls to the dll function to let the dll invoke a callback function.

I'd like both the calling function and the callback function to be LabVIEW vis.

Can this be done in LabVIEW? What is the best way to do this?

Here is the dll's register function prototype:

void CSregisterForMessages( long csHdl, void (*func)( void* data, long length, long type ) );



Thanks,

Jeff

Hi Jeff,
There is no direct way to register LabVIEW vi as callback function in C, but there is a way to work around by using the LabVIEW activeX server. Here are two links to info-labview that I answered before for your references.
http://messages.info-labview.org/2003/06/20/37.html
http://messages.info-labview.org/2004/01/27/09.html

The successful case is my IVision LabVIEW toolkit, it uses this technique to make LabVIEW vi as callback vi for real time video processing. If you want to get a feel how callback vi is working, you can download my Ivision at:
http://www.hytekautomation.com/Products/IVision.html

Regards,
Irene