Agilent Spectrum Analysis Basics - Agilent Technologies

Data transfer and remote instrument control
In 1977, Agilent Technologies (part of Hewlett-Packard at that time)
introduced the world’s first GPIB-controllable spectrum analyzer, the 8568A.
The GPIB interface (also known as HP-IB or IEEE-488) made it possible to
control all major functions of the analyzer and transfer trace data to an
external computer. This innovation paved the way for a wide variety of
automated spectrum analyzer measurements that were faster and more
repeatable than manual measurements. By transferring the raw data to a
computer, it could be saved on disk, analyzed, corrected, and operated on
in a variety of ways.
Today, automated test and measurement equipment has become the norm,
and nearly all modern spectrum analyzers come with a variety of standard
interfaces. The most common one remains GPIB, but in recent years,
Ethernet LAN connectivity has become increasingly popular, as it can
provide high data transfer rates over long distances and integrates easily
into networked environments such as a factory floor. Other standard
interfaces used widely in the computer industry are likely to become
available on spectrum analyzers in the future to simplify connectivity
between instrument and computer.
A variety of commercial software products are available to control spectrum
analyzers remotely over an I/O bus. You can also write your own software
to control spectrum analyzers in a number of different ways. One method is
to directly send programming commands to the instrument. Older spectrum
analyzers typically used proprietary command sets, but newer instruments,
such as Agilent’s ESA and PSA spectrum analyzers, use industry-standard
SCPI (standard commands for programmable instrumentation) commands.
A more common method is to use standard software drivers, such as
VXIplug&play drivers, which enable higher-level functional commands to the
instrument without the need for detailed knowledge of the SCPI commands.
Most recently, a new generation of language-independent instrument drivers,
known as “interchangeable virtual instrument,” or IVI-COM drivers, has
become available for the ESA and PSA families. The IVI-COM drivers are
based on the Microsoft Component Object Model standard and work in a
variety of PC application development environments, such as the Agilent
T&M Programmers Toolkit and Microsoft’s Visual Studio .NET.
Some applications require that you control the spectrum analyzer and
collect measurement data from a very long distance. For example, you may
want to monitor satellite signals from a central control room, collecting
data from remote tracking stations located hundreds or even thousands
of kilometers away from the central site. The ESA and PSA Series spectrum
analyzers have software options available to control these units, capture
screen images, and transfer trace data over the Internet using a standard
Web browser.
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