User`s guide

Building a VISA Application in Windows 2
Agilent VISA User’s Guide 17
%s\n", buf);
/* Close session */
viClose(vi);
viClose(defaultRM);}
C/C++ Sample Program Contents
A summary of the VISA function calls used in the preceding
sample C/C++ program follows. For a more detailed
explanation of VISA functionality, see Chapter 3,
“Programming with VISA.” See the VISA Online Help for
more detailed information on these VISA function calls.
Table 2 Summary of VISA Function Calls Used in the C/C++ Sample
Function(s) Description
visa.h
This file is included at the beginning of the program to
provide the function prototypes and constants defined by
VISA.
ViSession
The ViSession is a VISA data type. Each object that will
establish a communication channel must be defined as
ViSession.
viOpenDefaultRM
You must first open a session with the default resource
manager with the viOpenDefaultRM function. This function
will initialize the default resource manager and return a
pointer to that resource manager session.
viOpen
This function establishes a communication channel with
the device specified. A session identifier that can be used
with other VISA functions is returned. This call must be
made for each device you will be using.