LabVIEW VI for Interfacing with Tektronix MSO4000 Oscilloscopes
Project Overview
The Tektronix MSO4000 series of oscilloscopes are mixed-signal oscilloscopes that contain both digital and
analog channels. A previously developed custom step in National Instruments SignalExpress™ can be used to
remotely control the analog channels of the oscilloscopes, but there is currently no means to remotely control
the digital channels and buses. Our project is [was] to design and implement a LabVIEW Virtual Instrument that
will allow a user to remotely configure and control the oscilloscope as well as acquire, analyze, and document
measurements from the digital channels and bus waveforms.
We designed a virtual instrument that will allow a user to remotely operate a Tektronix MSO4000 series
oscilloscope using National Instruments LabVIEW. The purpose of this VI is to allow a person to control the
oscilloscope by manipulating the controls in the user interface of this VI, rather than manipulating the controls
that are on the front panel of the oscilloscope itself. Manipulating a control in LabVIEW should have the same
effect on the oscilloscope as manipulating the equivalent control on the front panel of the oscilloscope. The user
will be able to remotely control the digital channels, the buses, and the triggering features from LabVIEW. The
interface allows the user to configure the digital buses and channels and adjust the trigger settings. It will also
provide the user with control of other features, like enabling automatic measurements. The VI will also display an
image of the waveform in LabVIEW and allow the user to acquire and save measurement data from the
oscilloscope.
We implemented our solution with a collection of individual virtual instruments, which are then packaged in a
top-level master VI. The top level VI plots the waveform data on the graph while simultaneously governing
execution all of the constituent VIs that are responsible for the configuration of the various feature groups of the
oscilloscope. The configuration Vis are presented in a tabbed layout that allows the user to quickly and
seamlessly switch between them, while never having to leave the waveform display - thus ensuring a smooth
and seamless workflow. [A different configuration VI is selected by clicking on the appropriate tab of the top
level VI. ]
The Tektronix MSO4000 series mixed-signal oscilloscope is capable
of analyzing both analog and digital signals, and includes specialized
high-level functionality for analyzing and interpreting multichannel
digital and bus waveforms. Sixteen digital inputs combine with the
four analog inputs for a total of twenty channels. These inputs can
be viewed and measured as individual digital waveforms or can be
fully decoded using automated serial and parallel bus analysis with
a selection of nine different communication bus protocols,
including Parallel, I2C, SPI, LIN, CAN, RS-232, FlexRay, USB, and
Audio.
Digital Channel VI
The MSO4000 series includes
a set of dedicated digital
input channels, much like a
logic analyzer.
This VI allows the user to
configure and control the 16
digital channels, D0-D15.
The user is able to:
• Turn each of the 16 digital
channels on or off, either
individually or in groups of
eight
• Adjust the height of the
digital channel waveforms
• Turn the MagniVu feature
on or off
• Adjust the vertical position
of the digital channel
waveforms
• Edit the text labels of each
digital channel
• Set the logic threshold
voltages for the digital
channels
Bus Configuration VI
The serial bus decoding of
the MSO4000 series is a
powerful and deep feature.
This VI allows the user to
completely configure all
four serial buses, B1-B4.
Bus Trigger VI
Each serial bus on the
MSO4000 features fully
configurable triggering.
This VI allows the user to
configure triggering all four
buses.
The user is able to:
• Enable/disable display of
each bus individually
• Change the decoding type
for any given bus in two
mouse clicks
• Configure all input sources
and decoding parameters
for all bus types (listed at
far left)
• Select bus display type
(Bus and Waveforms, or Bus
Only)
• Select the bus display
format for each bus (Binary,
Hexadecimal, ASCII, Signed
Decimal, Mixed, and
Mixed2)
• Adjust the vertical
position of each bus and its
associated waveforms
• Edit the text labels of each
bus
• Set logic threshold
voltages for each channel of
a selected bus type
The user is able to:
• Select the event type on
which to trigger. Each bus
type has its own set of
potential triggering events,
and all are represented in
the VI.
• Configure all triggering
parameters for the chosen
event type. Each type of
event has a particular set of
parameter associated with
it, and
Digital Measurement VI
The MSO4000 includes a
suite of channel-to-channel
measurement and
comparison option.
This VI allows the user to
execute and display the
results of measurements
between up to four of the
digital channels, D0-D15,
replicating the scope’s
front-panel functionality.
Available measurements
include:
•
National Instruments LabVIEW is a powerful graphical programming
environment for developing sophisticated measurement, test, and
control systems. It is especially well-suited for rapid development of
user-friendly interfaces capable of controlling complex hardware of
all kinds. In LabVIEW, applications called Virtual Instruments (VIs),
and they are constructed by wiring together different graphical icons
instead of writing lines of text. Each graphical icon is a functional
block ranging from simple arithmetic and boolean logic operators to
GPIB and VISA hardware communications, control, and data transfer.
LabVIEW allows the developer to quickly lay out a visually appealing
and user-friendly front panel interface, the elements of which can
then be connected to VI applets on the Block Diagram (the ‘source
code’). By thinking hierchially and planning ahead, portions of code
which will be repeatedly useful can be saved as VIs themselves and
incorporated into future programs.
Sponsored by Tektronix Corporation of America / Faculty Advisor: Dr. Garrison Greenwood
Team Members: David Ardito, Jinho Park, David Richoux, Calen Uhlig / Special thanks to Jeff Yost and Ian Dees at Tektronix
Department of Electrical and Computer Engineering