How do I use Windows CALLBACK in CVI

[GeoffCox]

I am trying to use ReadEx() and WriteEx() in a CVI project after opening a device in overlapped mode using CreateFile(). I have supplied a windows CALLBACK functions for each operation and it all builds OK, but the CALLBACK functions are not being called. It seems the WIN32 events are not getting back to CVI - Are there any examples of how this can be done.

Thanks,

Geoff

[RobertoBozzolo]

I suppose you must register a CVI callback to be issued when a specific Windows message is received: this is done by means of RegisterWinMsgCallback function.

Here a small tutorial on how CVI handles Windows messages. A search in the forum will also return a small number of discussion that can help you in using the command; I'm afraid I cannot help you much more than this as I have no deep knowledge on it.