LabWindows/CVI
exporting a variable or function defined in an import library is not supported
There seems a lot of confusion in this thread. First a CIN is a Code Interface Node and it requires a very specific interface to be exported to work Those CINRun, CINLoad, CINUnload, etc functions. CIN's are old legacy technology and rumors have it that LabVIEW 2009 does not support them anymore, or maybe it's just the 64 Bit variant.
A DLL is imported into LabVIEW using the Call Library Node. There is no need to wrap a DLL into functions for the mere ability to import those functions. But wrapping DLL functions can be sometimes necessary when the DLL takes complicated parameters, such as structs containing pointers or other similar complicated stuff. LabVIEW offers the possibility to configure parameters to be C strings or C array pointers but does not allow configuring the type of embedded elements in a cluster/struct and that is a bummer since LabVIEW handles are not compatible with standard C pointers. So a wrapper takes care of taking various individual parameters and putting them together to pass as complicated structure to the real function.
Another need for a wrapper are call back functions. LabVIEW does not support callback pointers as DLL parameters. So the wrapper has to convert the callback event into an event compatible with LabVIEW such as an OS event, a LabVIEW Occurrence or User event.
You should be able to add the DLLEXPORT keyword to the function implementation, but migh have trouble if you also have a header file that contains the same function name without that keyword.
