Directly accessing the gpib-32.dll exports, Directly accessing the gpib-32.dll exports -13 – National Instruments NI-488.2 User Manual

Page 50

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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

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