Technical data

148 Chapter 9
Programming Examples
Programming in C Using the VISA
Programming Examples
XI0::24::INSTR Device at VXI logical address 24 that is of VISA type
INSTR.
VXI2::128 Device at VXI logical address 128, in the third VXI
system (VXI2).
GPIB-VXI0::24 A VXI device at logical address 24. This VXI device is
connected via a GPIB-VXI command module.
GPIB0::7::0 A GPIB device at primary address 7 and secondary
address 0 on the GPIB interface.
TCPIP::[e-mail]::INSTR
A TCPIP device using VXI-11 located at the specified
address. This uses the default LAN Device Name of
inst0.
The following is an example of opening a device session with the GPIB
device at primary address23.
ViSession defaultRM, vi;
.
.
viOpenDefaultRM (&defaultRM);
viOpen (defaultRM, "GPIB0::23::INSTR", VI_NULL,VI_NULL,&vi);
.
.
viClose(vi);
viClose (defaultRM);
Closing a Session
The viClose function must be used to close each session. You can close
the specific device session, which will free all data structures that had
been allocated for the session. If you close the default resource manager
session, all sessions opened using that resource manager will be closed.
Since system resources are also used when searching for resources
(viFindRsrc) or waiting for events (viWaitOnEvent), the viClose
function needs to be called to free up find lists and event contexts.