Tektronix MSO4000 Series Oscilloscope Digital Channels Remote Interfacing

LabVIEW VI

June 3, 2010

David ArditoJinho Park

David RichouxCalen Uhlig

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PSU ECE Department Senior Capstone Project

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Acknowledgments

Tektronix Inc. Jeff Yost Ian Dees

Portland State University Dr. Garrison Greenwood Mark Faust Philip Wong Amy Jolstead

Problem Description

• MSO oscilloscopes are equipped with interfaces that enable remote control of the scope from a PC.

• Existing SignalExpress ™ custom step supports remote control of analog channels.

• There has been no means to control digital channels and buses.

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Requirements

• Design and implement a user interface VI that enables remote control of digital channels from a PC.

• Required Features– Configure the digital channels and buses parameters– Adjust the trigger settings. – Display digital waveforms– Acquire measurement data

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Design Approach

• Modular Design– Oscilloscope functionalities are divided into five

groups• Digital Channel• Bus Configuration• Bus Trigger• Digital Measurement• Digital Waveform

– Each group is implemented individually.– Followed by integrating VIs ASa single standalone VI

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Design Approach

Design Approach

• Individual VI Design– Each VI provides own user interface.– User interactions are handled by event structures.• Text commands are generated and issued to the

oscilloscope according to the user inputs.– Interactive controls are updated after commands

and queries are processed• Represent the current oscilloscope state

Development Environment

• Software– National Instrument LabVIEW 2009 Professional– National Instrument LabVIEW 2009 Student Edition

• Hardware– Tektronix MSO4XXX Oscilloscope• Firmware Version - XXXX

– Tektronix custom bus signal generator board

Results

• MSO4000 Computer Interface Digital Channel Digital Measurement Bus Configuration Trigger Configuration Digital Signal Display

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Features

• Settings displayed in VI in real time

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Testing

• Complete testing of every button press• Complete testing of every entered value• Complete testing of every menu display• VI display synchronized with oscilloscope• A Pass is when VI action completely

duplicates action performed on oscilloscope

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Deliverables

• Final LabView Code for all VIs• User Manual for all VIs• Completed Test Plan and Results• Final Report• All borrowed hardware

Test Board• Return badges

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Future Enhancements

• Visible and invisible menus instead of Tab or disabled and grayed out

• Integration into Signal Express

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Questions

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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 programming environment for developing sophisticated measurement, test, and control systems. It is especially well-suited for rapid development of user-friendly visual interfaces capable of controlling complex hardware of all kinds. In LabVIEW, applications called Virtual Instruments (VIs) are constructed by wiring together different functional blocks, instead of writing lines of text. These functional blocks have vastly wide-ranging capabilities, from simple arithmetic and Boolean logic operators to external hardware communications, control, and data transfer/logging/analysis via the industry-standard VISA API. LabVIEW enables the developer to quickly lay out a visually appealing and user-friendly front panel interface and worry about the programming later. In addition, by thinking hierarchically and planning ahead, portions of code which will be repeatedly useful can themselves be saved as sub-VIs and incorporated into later projects, thus further streamlining future development.

LabVIEW VI for Interfacing with Tektronix MSO4000 Oscilloscopes

The Tektronix MSO4000 series mixed-signal oscilloscopes are capable of recognizing both analog and digital input signals, and are packed with specialized high-level functionality for analyzing and interpreting multichannel digital and bus data. Sixteen digital inputs can combine with the four analog inputs for a total of twenty bits of simultaneous input. These inputs can be viewed and measured as individual waveforms or can be grouped and 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.

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

Achievements

3rd Place in Poster Competition