.TH visa 7visa "29 January 2013" "LibreVISA" "LibreVISA Programmers' Manual"
.SH NAME
visa \- Virtual Instrument Software Architecture
.SH SYNOPSIS
.B #include <visa.h>
.SH DESCRIPTION
The Virtual Instrument Software Architecture provides a generic interface
for communication with test and measurement equipment. 
.SS Resource Names
Each device is identified by a resource name that specifies the type of
connection used, location information and the device type.
.TP
.B USB Devices
.BR USB [\c
.IR bus ]\c
.BI :: manufacturer :: product :: serial\c
.RB [ ::\c
.IR type ]
.sp
The
.I manufacturer
and
.I product
identifiers must be given as hexadecimal numbers prefixed with
.BR 0x .
The
.I serial
number is mandatory, even if the device would be unique otherwise.
.TP
.B Ethernet/VXI-11 Devices
.BR TCPIP [\c
.IR interface ]\c
.BI :: host\c
.RB [ ::\c
.IR type ]
.SS Resource Manager
Access to resources is mediated through a resource manager; while
technically there could be multiple instances, usually only the default
resource manager is used.
.sp
A handle to the default resource manager can be obtained from the
.BR viOpenDefaultRM (3visa)
function.
.SS Finding Devices
If the resource name is not known in advance, the resource manager can be
queried for a list of known devices by using the
.BR viFindRsrc (3visa)
function.
.sp
This function returns a
.B ViFindList
object (along with the first known resource), and further resource names
are then queried from the find list using
.BR viFindNext (3visa)
before finally freeing the list using
.BR viClose (3visa).