Agilent Technologies E6432A - Manual (Page 2)

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Introduction
Today’s VXI instruments communicate
with application programs through
plug&play drivers. In some cases,
these drivers are just one way to
communicate. For the E6432A
microwave synthesizer, its plug&play
driver is the only means of communi-
cation with the host controller or its
application programs.
This product note provides an
overview of the communication
process, the range of hardware and
software configurations supported,
and an introduction to the features
of the instrument made available
through the plug&play driver.
The E6432A microwave synthesizer
is a register-based device, rather
than a message-based device. There
are two reasons for this. First, the
E6432A is designed to be a system
source rather than a bench source, so
its user interface and command set
are simple and straightforward. A
register-based design supports this
application. Secondly, the E6432A
employs a fast-switching architecture
in both frequency and amplitude
switching. Switching times of less
than 400 µs can be achieved in real
customer applications only if the
E6432A processing time is kept to
well under 50 µs. This can only be
accomplished with a register-based
design.
Most modern automated test systems
use programming environments
and VXI interfaces that support the
plug&play driver architecture. These
systems will easily integrate the
E6432A. For systems using older,
legacy software and VXI interfaces,
support for the E6432A may require
rewriting and/or changing interfaces.
These conditions will be covered in
this note.
Programming Environments
To support the E6432A plug&play
driver, the operating system founda-
tion required by the host controller is
Microsoft Windows NT® 4.0, with
Service Pack 3 or above installed.
Other operating systems, such as
Windows 95/98, UNIX®, or MacOS
are not supported at introduction.
Application programs running on
Windows NT that are compatible
with the E6432A plug&play driver
are:
● HP VEE 4.0 or higher
● National Instruments LabView and
LabWindows/CVI versions 4.0
or higher
● Microsoft Visual Basic
version 5.0 or higher
● Microsoft Visual C/C++
versions 5.0 or higher
Application programs such as
Agilent Basic for Windows have no
provision for communicating with
plug&play drivers and are therefore
not supported.
VXI Interfacing
There are several interfacing choices
available from host controller to VXI
instruments. Three of these are sup-
ported by the E6432A plug&play
driver. They are:
● VXI Embedded Control (for exam-
ple, E6234A running Windows NT)
● National Instruments VXI-MXI-2
● IEEE-1394 ("Firewire")
(for example, E8491A)
The remaining VXI interfaces
(HP and National Instruments
GPIB-VXI, and National Instruments
MXI-1) are unsupported.
The VXI data specification for the
E6432A is A16/A24, D16/D32. Due to
the large size of frequency registers,
floating point arithmetic is a must.
The interface must be capable of
allocating a large block size of A24
address space (256k). GPIB inter-
faces are unsupported because they
are fundamentally message-based
interfaces. They are not designed to
communicate with register-based
instruments without special, propri-
etary software that must be written
and downloaded into their memories
prior to using the plug&play driver.
Microsoft, Windows and Windows NT are U.S. registered
trademarks of Microsoft Corporation.
UNIX is a registered trademark of the Open Group.