Chapter 7 Using the NI-VXI/NI-VISA Software
PCI-MXI-2 for Linux 7-2 ni.com
Interactive Control of NI-VXI/NI-VISA
The easiest way to learn how to communicate with your instruments is by
controlling them interactively. Use the VXI/VME interactive control utility
(vic or its text mode counterpart, victext) to write to and read from your
instruments. This utility displays the status of your VXI/VME transactions
and informs you of any errors that occur.
Refer to the online help for instructions on how to use victext and to learn
about the features of each.
Example Programs
The NIVXI/examples subdirectory contains various example programs
along with a makefile that show how to use various functions in the NI-VXI
software and how to develop application programs using these functions.
Make certain that the environment variable NIVXIPATH is set correctly as
described in Chapter 5, NI-VXI/NI-VISA Software Installation. Also refer
to your software utilities reference manual for additional examples.
For NI-VISA programming examples, look in VXIpnp/linux/
NIvisa/Examples.
Programming Considerations
The following sections contain information for you to consider when
developing Linux applications that use the NI-VXI/VISA bus interface
software.

Multiple Applications Using the NI-VXI and VISA Libraries

Multiple-application support is another feature in the NI-VXI/NI-VISA
libraries. You can have several applications that use the NI-VXI and/or
NI-VISA libraries running simultaneously. In addition, you can have
multiple instances of the same application running simultaneously.
TheNI-VXI/NI-VISA functions perform in the same manner whether you
have only one application or several applications (or several instances of
a single application) all using the NI-VXI/VISA libraries.
However, you do need to be careful in certain cases as described in the
Low-Level Access Functions section.