National Instruments NI-488.2 Benutzerhandbuch

This section describes items you should include in your application and 
provides general program steps with an NI-488.2 example. 

Include the following items in your application:

•

Header files—In a C application, include the header files 

windows.h

 

and 

decl-32.h

. The standard Windows header file, 

windows.h

, 

contains definitions used by 

decl-32.h

, and 

decl-32.h

 contains 

prototypes for the NI-488.2 calls and constants that you can use in your 
application. 

•

Error checking—Check for errors after each NI-488.2 call. 

•

Error handling—Declare and define a function to handle NI-488.2 
errors. This function takes the device offline and closes the application. 
If the function is declared as:

void gpiberr (char * msg); /*function prototype*/

Then, your application invokes it as follows:

if (ibsta & ERR) {

gpiberr("NI-488.2 error");

}

The following steps show you how to use the device-level traditional 
NI-488.2 calls in your application. The NI-488.2 software includes the 
source code for an example written in C, 

devquery.c

, and the source code 

for the example written to use direct entry to access 

gpib-32.dll

, 

dlldevquery.c

. The NI-488.2 software also includes a sample program 

written in Visual Basic, 

devquery.frm

. 

Use 

ibdev

 to open a device handle. The 

ibdev

 function requires the 

following parameters:

•

Connect board index (typically 0, for 

GPIB0

).

•

Primary address for the GPIB instrument (refer to the instrument user 
manual or use the 

FindLstn

 function to dynamically determine the