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Chapter 4 Developing Your NI-488.2 Application
© National Instruments Corporation 4-13 NI-488.2 User Manual
to get a pointer to the exported function, you just need to call
GetProcAddress passing the name of the function as a parameter. For
more information about the parameters to use when you invoke the
function, refer to the NI-488.2 online help. For instructions on accessing
the online help, refer to the Using the NI-488.2 Documentation section in
About This Manual.
The functions such as
ibfind, ibrdf, and ibwrtf all require an argument
that is a name.
ibfind requires an interface or device name and ibrdf and
ibwrtf require a file name. Because Windows supports both ASCII (8-bit)
and Unicode (16-bit) characters,
gpib-32.dll exports both ASCII and
Unicode versions of these functions. The ASCII versions are named
ibfindA, ibrdfA, and ibwrtfA. The Unicode versions are named
ibfindW, ibrdfW, and ibwrtfW. You can use either the Unicode or ASCII
versions of these functions with Windows.
In addition to pointers to the status variables and a handle to the loaded
gpib-32.dll, you must define the direct entry prototypes for the
functions you use in your application. For the prototypes for each function
exported by
gpib-32.dll, refer to the NI-488.2 online help. For
instructions on accessing the online help, refer to the Using the NI-488.2
Documentation section in About This Manual.
The direct entry sample programs illustrate how to use direct entry to
access
gpib-32.dll. For more information about direct entry, refer to the
online help for your development environment.
Directly Accessing the gpib-32.dll Exports
Make sure that the following lines are included at the beginning of your
C application:
#ifdef __cplusplus
extern "C"{
#endif
#include <windows.h>
#include "ni488.h"
#ifdef __cplusplus
}
#endif