The Team

Department of Electrical and Computer Engineering

The Tektronix MSO4000 series are mixed-signal oscilloscopes that feature 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 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.

The MSO4000 series devices are equipped with a VISA (Virtual Instrument Software Architecture) communications controller and an

accompanying command-line programming language which includes commands for almost every hardware action. This means of interfacing

proved invaluable to our project, providing us with a means of manipulating the device according to our software specifications. We needed to

design an interactive visual interface that could build and transmit appropriate text commands to the oscilloscope, which would cause the

device to reflect the user’s actions and selections within our interface.

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 user 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 have remote control over

the digital channels, the serial buses, and the bus triggering features from LabVIEW. It will also provide the user with a means to configure and

collect data from the scope’s built-in in digital channel measurement functions. The VI also displays an image of the waveform in LabVIEW and

allows the user to acquire and save measurement data from the oscilloscope.

We implemented our solution as 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 of the constituent VIs which configure 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, while never having to physically touch

the oscilloscope.

National Instruments LabVIEW is a powerful graphical programmingenvironment for developing sophisticated measurement, test, andcontrol systems. It is especially well-suited for rapid development ofuser-friendly visual interfaces capable of controlling complexhardware of all kinds. In LabVIEW, applications called VirtualInstruments (VIs) are constructed by wiring together differentfunctional blocks, instead of writing lines of text. These functionalblocks have vastly wide-ranging capabilities, from simple arithmeticand Boolean logic operators to external hardware communications,control, and data transfer/logging/analysis via the industry-standardVISA API. LabVIEW enables the developer to quickly lay out avisually appealing and user-friendly front panel interface and worryabout the programming later. In addition, by thinking hierarchicallyand planning ahead, portions of code which will be repeatedlyuseful can themselves be saved as sub-VIs and incorporated intolater projects, thus further streamlining future development.

LabVIEW VI for Interfacing with Tektronix MSO4000 Oscilloscopes

The Tektronix MSO4000 series mixed-signal oscilloscopes arecapable of recognizing both analog and digital input signals, and arepacked with specialized high-level functionality for analyzing andinterpreting multichannel digital and bus data. Sixteen digitalinputs can combine with the four analog inputs for a total of twentybits of simultaneous input. These inputs can be viewed andmeasured as individual waveforms or can be grouped and fullydecoded using automated serial and parallel bus analysis with aselection of nine different communication bus protocols, includingParallel, I2C, SPI, LIN, CAN, RS-232, FlexRay, USB, and Audio.

Sponsored by Tektronix Corporation of AmericaTektronix Representative: Jeff Yost

PSU Faculty Advisor: Dr. Garrison GreenwoodECE Team Members: David Ardito, Jinho Park, David Richoux, Calen Uhlig

Special thanks: Ian Dees – Tektronix,Mark Faust, Philip Wong, Amy Jolstead -Portland State University

Digital Channel VIThe 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 positions of the digital channel waveforms

• Edit the text labels of each digital channel

• Set the logic threshold voltages for each of the digital channels

Bus Configuration VIThe serial bus decoding of the MSO4000 series is a powerful feature. This VI allows the user to completely configure all four serial buses, B1-B4.

The user is able to:

• Individually enable/disable the display of each bus

• 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 the 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

Bus Trigger VIEach 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:

• Select the event type on which to trigger. Each bus type has its own set of potential triggering events, and all of them are represented in the VI.

• Configure all of the triggering parameters for the chosen event type. Each type of event has a particular set of parameters associated with it, and the VI displays only the parameters which pertain to the currently selected event type.

Digital Measurement VIThe 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:

• Frequency

• Period

• Phase Difference

• Delay

• Burst

• Positive Duty Cycle

• Positive Edge Count

• Positive Width

• Negative Duty Cycle

• Negative Edge Count

• Negative Width

MSO4000 Series Mixed-Signal Oscilloscopes

Configuration VIs

LabVIEW Programming Sample

Project Benefit Summarization

ECE Capstone Project Credits

Our Approach

Our Design

Project Overview