Visual basic (version 6.0), Direct entry with c, Gpib-32.dll exports – National Instruments NI-488.2 User Manual

Page 52: Gpib-32.dll exports -15

Chapter 4

Developing Your NI-488.2 Application

4-15

NI-488.2 User Manual

To compile and link a Win32 console application named

cprog

in a DOS

shell using the environment variable,

"NIEXTCCOMPILERSUPP"

, type in

the following on the command line:

bcc32 -I"%NIEXTCCOMPILERSUPP%\include" -w32 cprog.c

"%NIEXTCCOMPILERSUPP%\lib32\borland\ni4882.obj"

Borland/CodeGear does not have a 64-bit compiler at the time of this
writing.

Visual Basic (Version 6.0)

With Visual Basic, you can access the traditional NI-488.2 calls as
subroutines, using the BASIC keyword

CALL

followed by the traditional

NI-488.2 call name, or you can access them using the

set of functions.

With some of the NI-488.2 calls (for example

ibrd

and

Receive

), the

length of the string buffer is automatically calculated within the actual
function or subroutine, which eliminates the need to pass in the length as
an extra parameter. For more information about function syntax for Visual
Basic, refer to the NI-488.2 Help. For instructions on accessing the online
help, refer to the

Using the NI-488.2 Documentation

section in

About This

Manual

Before you run your Visual Basic application, include the

niglobal.bas

and

vbib-32.bas

files in your application project file.

Direct Entry with C

Direct entry is available for only the 32-bit

gpib-32.dll

, and not for

ni4882.dll

The following sections describe how to use direct entry with C.

gpib-32.dll Exports

gpib-32.dll

exports pointers to the global variables and all of the

NI-488.2 calls. Pointers to the global variables (

ibsta

iberr

ibcnt

and

ibcntl

) are accessible through these exported variables:

int *user_ibsta;

int *user_iberr;

int *user_ibcnt;

long *user_ibcntl;

Except for the functions that have string parameters such as

ibfind

ibrdf

, and

ibwrtf

, all the NI-488.2 call names are exported from