Programming In C Using The Vtl - Agilent Technologies N9340B Programmer's Manual

Programming in C using the VTL

Typical Example Program Contents
visa.h
ViSession
viOpenDefaultRM You must first open a session with the default resource manager
viOpen
N9340B Programmer's Guide
This section includes some basic information about
programming in the C language using Agilent VISA transition
library (VTL). Note that some of this information may not be
relevant to your particular application. For example, if you
are not using VXI instruments, the VXI references will not
be relevant.
The following table summaries the VTL function calls used in
the example programs.
This file is included at the beginning of the each file to provide the
function prototypes and constants defined by VTL. For C and C++
programs, you must include the visa.h header file at the
beginning of every file that contains VISA function calls:
#include "visa.h"
The ViSession is a VTL data type. Each object that will establish a
communication channel must be defined as ViSession. Sessions
must firstly be opened on the default resource manager, and then
for each resource you will be using.
with the viOpenDefaultRM function, and then for each resource
you will be using. This function will initialize the default resource
manager and return a pointer to that resource manager session.
viOpenDefaultRM(&sesn)
This function establishes a communication channel with the device
specified. A session identifier that can be used with other VTL
functions is returned. This call must be made for each device you
will be using.
viOpenDefaultRM(&sesn)
viOpen(sesn, rsrcName, accessMode, timeout, &vi)
Programming Example 4
33