Distance Learning Solutions Guide - National Instruments · Distance Learning Solutions Guide ......

ContentsOverviewUsing LabVIEW for Remote Virtual Instrumentation Via the Internet by Jeffrey Travis........................................................2

Customer SolutionsRemote Manipulation with LabVIEW for Educational Purposes...............................................6

Conducting Experiments Over the Internet UsingLabVIEW and ComponentWorks ..............................8

CyberLab, A New Paradigm in Distance Learning...................................................10

Electronic Instrumentation Laboratories on the Net................................................................12

Mechanics of Materials Experiments Via the Internet .......................................................14

Distance Learning Solutions Guide

ActiveMath™ Analysis Advisor™ AutomationView™ AutomationWeb™ BioBench™ BridgeVIEW™ CodeBuilder™ CodeLink™ ComponentWorks™ Citadel™ CVI™ CVI logo™ DASYLab™ DataSocket™ DAQAnalyzer™ DAQArb™ DAQCard™ DAQ Designer™ DAQInstruments™ DAQMeter™

DAQScope™ DAQPad™ DAQPnP™ DAQSourceCode™ DAQ-STC™ DAQValue™ DAQWare™ Developer Suite™ EagleWare™ FieldPoint™ FlexADC™ FlexFrame™ FlexMotion™ HiQ™ HiQ-Script™ HotPnP™ HS488™ IMAQ™ InsideVIEW™ Instrument Studio™ Instrumentation Newsletter™

InstrumentationWeb™ Instrupedia™ LabSuite™ LabVIEW™ Lookout™ LabWindows™/CVI MANTIS™ Measure™ Measurement Ready™ logo Measurement Studio™ MicroGPIB™ MIGA™ MITE™ MXI™ National Instruments™ National Instruments logo (Eagle gets a ™) natinst.com™

NAT4882™ NAT7210™ NAT9914™ NI-488™ NI-488M™ NI-488.2™ NI-488.2M™ NI Business Center™ NI-CAN™ ni.com™ NI-DAQ™ NI Developer Zone™ NI-DNET™ NI-DSP™ NI-FBUS™ NI-IMAQ™ NI-SHELL™ NI-PGIA™ NI Prime Access™ NI-VISA™ NI VXI™ NIWeek™ PXI™ and logo PXI Configurator™ RTSI™ SCXI™ SmartCode™ SpectrumWare™ StillColor™ Take Measurements Not Estimates™ TestStand™ The Software is the Instrument™ The Virtual Instrumentation Company™ TIC™ Test & Measurement Explorer™ TNT4882™ TNT4882C™ TNT4882I™

Turbo488™ ValueMotion™ VI UserNet™ VirtualBench™ VMEpc™ VXI Integrator™ VXIpc™ VXIupdate™ World Wide Instrumentation™ Your Measurement and Automation Superstore™

© Copyright 2000 National Instruments Corporation. All rights reserved. Product and company names listed are trademarks or trade names of their respective companies.

Why NetworkedInstrumentation?Consider these real-world scenarios:On one early morning at a university campus, a student gets ready to do her homeworkexperiments as part of themechanical engineeringlab course. She realizes the assignment is due this morning and the lab won’t be open for

another couple of hours. Besides, the dorm room is cozy. Drinkingher coffee, she opens her Web browser and uses a Java applet interfaceto remotely connect to the lab equipment running LabVIEW.Running the experiment in real-time from the Web browser, sheinputs several parameters until she is satisfied with the voltage-loadgraphs. She saves the graphs and e-mails the results to her professor,turning in her assignment a few minutes before it was due.

A unique high-power electron microscope has just beenpurchased by an internationally-funded research agency. Althoughthe electron microscope is located in California, it is available toresearchers in Russia. The Russian scientists do not need to travel tothis facility, because they can control the settings, run experiments,and retrieve images remotely from specimens thanks to an Internet-enabled system. Because it is night-time in the U.S. during businesshours in Moscow, both American and Russian scientists have themicroscope available to them over the Net throughout the day.

Classifying an Internet-EnabledInstrumentation SystemThe previous stories illustrate the possibilities of combining virtualinstrumentation and the Internet. What kinds of applications arepossible when your systems use network and Internet technology? Whatadvantages are there to Internet-enabling your test lab or manufacturingprocess? The answer usually falls into one or more of the followingfunctional categories of Internet-enabled instrumentation:

Remote monitoring – is when a process is observed from anotherlocation on the network. You observe through a client while theprocess runs on a server. In a pure remote monitoring scenario, theclient cannot give feedback or provide inputs to the server process.

Remote control – usually includes the same capabilities as a remote monitoring system, but the remote user (the client) can send some data, messages, or inputs back to the server process thatin turn affects the output.

Collaboration – several users from remote sites use a client programto not only communicate and share information with the serverprocess, but be aware of and share information with each other aspart of the communication.

2

Using LabVIEW for Remote Virtual Instrumentation Via the Internet: An Overview

by Jeffrey Travis

National InstrumentsTel: (512) 794-0100 • Fax: (512) 683-9300 • [email protected] • ni.com/academic/distance_learning.htm

Virtual Instrumentation, LabVIEW, and the InternetThe concept of virtual instrumentation is to create more powerful,flexible, and cost-effective instrumentation systems built around a PCusing software as the engine and interface. A virtual instrument caneasily export and share its data and information with other softwareapplications because they often reside on the same computer.

When National Instruments introduced LabVIEW over a decade ago, it established a unique software tool for creating virtualinstruments. The appeal of LabVIEW is largely tied to its graphicalprogramming nature, because it is very easy to prototype and developan application in a fraction of the time it would take to produce thesame in a language such as C++. There is an interesting parallelbetween the success and popularity of LabVIEW and the popularity ofthe Web. In both cases, it was not so much the underlying technologythat was so innovative, but rather the well designed graphical interfacethat made it accessible. After all, almost everything you could do inLabVIEW could be done in C or assembly code years beforeLabVIEW was popular. The Internet’s use goes back to the ’60s. Most of what it took to create these revolutionary tools, though, was the development of an intuitive, human-friendly interface. ForLabVIEW, that meant programming by wiring graphical objectstogether, like building a breadboard circuit. For the Web, it meant a “Web browser” application that involves little more than justpointing and clicking on images or words that are of interest, and are hyperlinked to other places on the Web.

So you might say that using LabVIEW to create Internet-enabledapplications brings some of the best user interface designs together. The possibilities are exciting for creating easy-to-use and intuitivenetworked applications that take virtual instrumentation to a new level.

3National InstrumentsTel: (512) 794-0100 • Fax: (512) 683-9300 • [email protected] • ni.com/academic/distance_learning.htm

Client Server System

ClientSoftware?

WhatClassification?

Web Based

VI-Based

Web Components

Monitoring Control – User Input Required

YesYes

No

No

DistributedComputing System

Type ofInteraction?

Real-time updatesor high speed?

UseNetscapeClientwith pushanimation

CGI on G Web

Server

ActiveXComponent

JavaApplets

G Web Server

LabVIEW Components

DataSocket

VI Server

TCP VIsRequire animatedgraphical data?

Flowchart to Choose LabVIEW Internet Technologies

Choosing a Technical Solution with LabVIEWWhen designing an Internet-enabled instrumentation system withLabVIEW, you have a wide array of choices and tools at yourdisposal. LabVIEW has a number of built-in capabilities for Internetconnectivity, including:• TCP/IP and UDP functions• Built-in Web server that can create front panel images on-the-fly• VI Server – a powerful framework for VIs or ActiveX applications

to communicate over a network• DataSocket support for using National Instruments

DataSocket protocol

You can use LabVIEW with additional technologies and softwarepackages such as:• Java applets to remotely control or monitor a VI• ActiveX controls• CGI support in the G Web server• E-mail, ftp, and telnet

A very common question people have when designing anInternet-enabled system is “which technologies should I use for myapplication?” The flowchart above shows you a general decision

process for deciding what technologies to use. The decision processassumes that you are using LabVIEW as a data server in somecapacity and does not take into account interfacing with othersoftware systems (excluding the Web).

DataSocket vs. VI ServerHere is the general rule to decide when to use DataSocket and whento use VI server:

Use VI Server when you need to share processes and interfaces; for example, if you need to call a VI’s functionality remotely, or displayits front panel.

Use DataSocket when you want to share live data, independentlyof how you are displaying, storing, or obtaining it. Also you should useDataSocket if you want data to be available to different type clients(VIs and the Web).

Web vs. VI ClientsA major consideration in any Internet-enabled system is whether theremote users need to have a custom VI to access your system, orwhether they can accomplish their tasks by using a Web browser.Table 1 on the following page compares these two choices.

4 National InstrumentsTel: (512) 794-0100 • Fax: (512) 683-9300 • [email protected] • ni.com/academic/distance_learning.htm

Ability to interact with controls(knobs, switches)

Ability for user to type in text or form data

Ability to display live, animated data(e.g., stripcharts, gauges)

Multiplatform support

Tools recommended for development

Security considerations

Possible with imagemaps,but very limited; requiresreloading of page.

Very easy with HTMLforms; main purpose of CGI.

No

Yes. All browsers work withCGI.

Internet Toolkit for G(National Instruments).

Possible security threats toserver if CGI program is notdesigned right; none toclient.

Yes

Yes, but more complex thanCGI.

Yes

Yes. Most browsers workwith Java.

Virtual InstrumentationBeans (ErgoTech) plus a Java IDE; or AppletVIEW(JeffreyTravis.com)

Very little security concernsto client or server, becausesandboxing limits what Javaapplets can do.

Yes

Yes, but more complex thanCGI.

Yes

No. Only Internet Exploreron Windows can useActiveX controls.

National InstrumentsMeasurement Studio plusVisual Basic.

Security threats to clientfrom unstable or maliciousActiveX controls.

Table 2. A Comparison of CGI, ActiveX, and Java

CGI Java ActiveX

Control on the Web – A Comparison of CGI, ActiveX, and JavaAs you know, displaying data on the Web from LabVIEW is easythanks to the built-in Web server. You can even display animatedfront panels on Netscape browsers using the special monitor.However, if you need to control or have users interact with yourLabVIEW system over the Web, then you must choose betweenCGI, ActiveX, and Java applets for your solution. Table 2 contraststhe differences between these three.

ConclusionThe world of Internet-enabled instrumentation is just beginning toexplode, especially in applications for distance-based education andremote labs. Using LabVIEW as the platform of choice is one of theeasiest, fastest ways to get your instrumentation system on theInternet. A variety of technologies, using the Web as a primaryinterface medium, are currently compatible with LabVIEW.

To take a course on using LabVIEW for remote virtualinstrumentation please visit ni.com/custed

Web-Based Clients

• No special software to install; remote users only need a browser

• Lower maintenance and upgrade costs, because all code resides on server

• Easier for clients to use• Security – no source code ever is on the client machines• Wide platform support

• Remote control is far more complex to implement; requires CGI, Java or ActiveX programming

• Security – anyone with a browser could potentially access the system

VI-Based Clients

• Remote control and interactivity much easier to program, because it is all in LabVIEW

• More flexibility in choice of user interface, behavior• Security – only users with access to the client VIs can use

the system

• Requires that remote user have the current version of LabVIEW installed or distribute large executables

• Security – remote users may have access to source code• More costly and complex maintenance – changes may

require all users to download a new client program

Pros

Cons

Table 1. Web vs. VI Clients


National InstrumentsWeb Site forAcademia ni.com/academicNational Instruments has anestablished measurement andautomation Website that givesusers easy access to an enormousamount of information forassistance in developing,configuring, and maintaining

computer-based measurement and automation systems. The Website is designed to be a complete resource for your instructional orresearch needs. You can access the information by selecting yourdiscipline and your application (instructional or research). If you arefamiliar with National Instruments products, you will find directlinks to desired information. Students link to a special page wherethey can find information about job listings, internship and co-opopportunities, and LabVIEW-based projects.

Internet Applications in LabVIEW is a tutorial and reference volume for LabVIEW programmers who want to learn toapply the latest Internet technologies to their LabVIEW solutions. The book covers in-depth topics such as TCP/IP, VI Server, DataSocket, ActiveX, Java, Web servers, network security, e-mail, and more.

The author’s approach provides the necessary background information on Internet technologies, and then demonstrateshow to apply them to LabVIEW. From client-server motion programs (VIs) to remote control over the Web, the textguides readers through hands-on activities and examples, with the source code on the enclosed CD.

For more information on this book and the associated LabVIEW-Internet connectivity course, visitJeffreyTravis.com/books

About the Author Jeffrey Travis is the author of the Internet Applications in LabVIEW (2000, Prentice-Hall) textbook and co-author with Lisa Wells of LabVIEW ForEveryone (1997, Prentice-Hall). For more information contact [email protected], or visit his web page at JeffreyTravis.com

ni.com/academic/distance_learning.htm


CUSTOMER SOLUTIONS

These two parts are linked through acommunication layer built on LabVIEWDistributed Computing Tools.

Distributed Computing ToolsNational Instruments has introduced anapproach to call a subVI in LabVIEW,referred to as a call-by-reference. Thisprinciple is similar to Remote Procedure Call (RPC) under Unix. This approach isimplemented with LabVIEW, which meanssimplicity and ease of use. Using this newmechanism, we can call a subVI on a local or a remote machine using TCP/IPtransparently. The only difference betweenthese two types of calls is the need to definethe IP address and IP port of the remotemachine. The remote machine, acting as aserver, needs to be correctly configured. Prior to calling the subVI, the user needs to establish a connection with the server.

by Denis Gillet, Christophe Salzmann, and Eduardo Gorrochategui, Swiss FederalInstitute of Technology – Lausanne (EPFL)

The Challenge: Manipulating aphysical setup located in a remotelaboratory, so that teachers caninstruct from the classroom andstudents can learn from home.Providing distance access fromcampus as well as worldwide.The Solution: Taking advantageof LabVIEW capabilities, such asDistributed Computing Tools, tobuild a link over the Internet betweenclient computers and the physicalsetup. Designing a user interface thatreproduces the look and feel of thelocal environment on the client sideby combining virtual representationsand live video feedback of the distant setup.

IntroductionInstructors need to have a distance learningopportunity readily available for classroomteaching. To avoid moving the experimentalsetup to the classroom or to overcome thedifficulties of accessing laboratory facilities atany time, it is useful to provide interactiveand remote access to such facilities. Wedesigned a multiplatform client-serversolution based on personal computers, whichshare information through the Internet, toserve this paradigm. LabVIEW is clearly theideal candidate to provide the high level ofinteractivity and interoperability required for educational purposes.

The Laboratory EnvironmentOne of the physical setups available forstudying motion control at the Swiss Federal

Institute of Technology in Lausanne (EPFL) is composed of the realprocess – a servo drive –connected to a PowerMacintosh via a dataacquisition (DAQ) board(National InstrumentsPCI-1200). The controlsoftware piloting the realprocess locally is a virtualinstrument (VI) built using LabVIEW. An in-house real-time kernel extends LabVIEWcapability and guarantees high-speed andaccurate pace. The VI provides a completeinterface between the user and the realprocess. It is used to generate excitationsignals and observe corresponding responses.The main concept of such an interface is to provide a general view of the realprocess evolutions and facilitate full controlof the operations.

The CommunicationArchitectureGiven its fully computer-basedimplementation, we can easily expand the laboratory environment for remotemanipulation. The main concept in turningthe locally controlled setup into a remotelycontrolled one consists of moving the userinterface away from the experiment. Twodistinctive parts result – the remote client and the local server.• The remote client is a computer

equipped with the user interfacefunctions. The client softwarewith which the users canobserve and act on the remoteexperiment is an executableapplication compiled for thetarget platforms using theApplication Builder.

• The local server is the computerlocated in the laboratory andequipped with the hardwareinterface to the sensors andactuators. The server softwarereceives the client commandsand transmits them to the real process. It also returns the state of the real process to the client.

The high-level networking

capabilities of LabVIEW empower

instructors to implement virtual

instruments for remote manipulation

in a highly efficient manner, both from

a time and resource point of view.

Education■ Application Builder■ DAQ■ LabVIEW■ Picture Control Toolkit

Remote Manipulation with LabVIEW for Educational Purposes

The Teacher and the Remote Setup in Action

A Simple “Call-By-Reference” Example

CUSTOMER SOLUTIONS


PowerBook G3)equipped with a built-in Ethernet interfaceand is manipulated by the teacher. Thestudents can watch acopy of the computerscreen projected onto the wall.

We perform remotemanipulation of theservo drive during thelecture to enlighten the presentation of the subject matter.According to the topicstudied, instructors can select differentconfigurations –

position or speed control, P, PI or PIDcontrollers with different sets of parameters.

The user interface of the control softwareis presented in the figure at left. It consists of an oscilloscope signal visualization, asignal generator providing the reference, andparameter settings for the controller. Anadditional window provides a reconstructedvirtual representation of the dynamicevolution (actual position of the rotating disk) driven by the transmitted measurements. We use the LabVIEW Picture Toolkit for this purpose.

The image and the sound of the physicalsetup are transmitted to the user with videoconferencing software. The audio/video server runs in parallel and independently of LabVIEW on the computer connected to the real process (server).

ConclusionsThe LabVIEW Distributed ComputingTools give us the ability to perform highlyinteractive remote manipulation inside aninstitution equipped with an Intranet. Thisrequires only minor changes when a localsolution already exists. Therefore, it is well-suited for live demonstrations conducted

by the instructor in the classroom or forexperimentation carried out by studentsfrom a computer room. In this way, practicetime is unrestricted. You can apply the sameapproaches for teaching and learning usingremote facilities from home or even overseasconnections. This requires the integration of lower level LabVIEW tools (IP) to use the available bandwidth wisely.

Compared with experimentation invirtual reality, remote manipulation on realprocesses is easier to implement and moreversatile. In fact, adding or selecting anotherphysical setup does not involve theelaboration of complex mathematical models and graphical representations.

Finally, remote experimentation is notlimited to education. In research andindustry, remote accesses also represent aninteresting opportunity to meet the growingneed of scientists who wish to share uniqueor expensive equipment and to give supportengineers the ability to operate immediatelyat customer facilities. The high-levelnetworking capabilities of LabVIEWempower instructors to implement virtualinstruments for remote manipulation in ahighly efficient manner, both from a timeand resource point of view.1

For more information, please contact Denis Gillet and Christophe Salzmann, Swiss Federal Institute of Technology –Lausanne, IA – DGM – Ecublens, CH – 1015 Lausanne, Switzerland,[email protected] [email protected]

On termination, the connection needs to be closed. A simple example of a remote machine transmitting its local time is shownin the figure at the top of this page.On the server side, the user can specify accessby allowing or denying given addresses ordomains. The user can also restrict access tothe VIs called. To implement the remotemanipulation of the setup, we used four call-by-reference VIs. The first one transmitsthe controller parameters from the client tothe server, the second sends the measuredvalues from the server to the client, and thelast two implement watchdogs to detect ifthe client or the server are still available.

Application of Remote LaboratoryWe apply the remote manipulationparadigm regularly within the basicautomatic control course taught at the SwissFederal Institute of Technology in Lausanne.Students from electrical engineering,mechatronics, mechanical engineering, and computer science attend this coursesimultaneously (about 160 students) in alarge auditorium. The client software isinstalled on a portable computer (Apple

Client’s View

The LabVIEW Distributed

Computing Tools give us the ability

to perform highly interactive remote

manipulation inside an institution

equipped with an Intranet.

CUSTOMER SOLUTIONS


controllers, and control engineering are all suitable subjects for Web experiments.The figure illustrates a digital electronicsexperiment designed and coordinated overthe Internet, in which students can interactwith Switches 1 and 2 to observe output.

Besides simulations, it is useful for students to explore and conduct real-timeexperiments over the Internet. The figure on the next page depicts the setup requiredfor such an experiment. In this situation,students use Internet Explorer or NetscapeCommunicator as the user interface andinteract with the input settings. Studentssend the input settings over the Internet to the experiment, housed in a remote

by Pee Suat Hoon, Department of ElectricalEngineering, Singapore Polytechnic

The Challenge: Developing interactive experiments for studentsover the Internet.The Solution: Using technologiessuch as ActiveX, ComponentWorks,LabVIEW, and the InternetDevelopers Toolkit to conduct and transmit experiments over the Internet.

IntroductionEducation for engineers requires acombination of theoretical knowledge andpractical experience. Theories are discussedduring lectures while students gain practicalexperience in the laboratory throughexperiments. With laboratory work, studentscan find their own meaning through self-directed activity and further understand theconcepts covered during lecture.

Traditionally, educational softwaresystems have been tied to a particular type ofcomputer and operating system. However,with advanced technology such as ActiveX,users can now prepare the software systemsand make them available worldwide on theweb. The benefits of Web-based trainingmaterials include the independence oflocation, ease of use, accessibility, andreduced cost. Students are not required topurchase additional software using the web browser.

The impact of combining emergingtechnologies, educational animation systems,

and hypertext delivery mechanisms forstandard instruction as well as remotelearning from a virtual laboratory isprofound. There is great potential for Web-based training. In fact, Web-basedtraining may grow from $1.7 to $3 billion by the year 2000 (Control Engineering,December 1997).

Web-Enabled ExperimentsUser-interactive animations over the Internet conducting an experiment in aremote laboratory in real-time are twovariations of experiments that weredeveloped. Engineering subjects such asdigital electronics, programmable logic

Education/Electrical Engineering■ ComponentWorks■ LabVIEW

Conducting Experiments Over the Internet using LabVIEW and ComponentWorks

Several tools have eased

development of the above

interactive laboratory experiments.

These include Ispy, ActiveX

control pad, Visual Basic Control

Creation Edition, Internet control

components, and National Instruments

ComponentWorks.

Web-Enabled Experiment

CUSTOMER SOLUTIONS


web. Additional Internet and dataacquisition controls will be required forpreparing the experiment for remote control.Specifically, Winsock and analog outputcontrols will be required.

Preparing the OCX forInternet DownloadThe application setup wizard from VisualBasic Control Creation Edition is used forthis purpose. This wizard provides point-and-click forms where settings are entered.To use the forms, the “Create InternetDownload Setup” option must be chosen.Several files are created when the SetupWizard manages to collect the essentialinformation. The most important files arethe cabinet (.cab) and html files. The .cabfile contains all the information necessary to download, install, and register thecomponents required to run the controls on an HTML page. The benefits of this architecture include file compression for faster download, a single file to describe necessary files, and automaticinstallation information when the controlcomponent downloads.

ConclusionWe successfully conducted interactiveexperiments over the Internet using enabling technology such as ActiveX,National InstrumentsComponentWorks, LabVIEW, andthe Internet Developers Toolkit.1

Ms. Pee Suat Hoon is a lecturer with the Department of Electrical Engineering, Singapore Polytechnic. She can be contacted by email at [email protected]

laboratory. The experimental rig producesoutputs that National InstrumentsLabVIEW monitors. Students can publishresults with the click of a button using the Internet Developers Toolkit. Afterapplying the necessary input conditions,students then wait to see results from thesame Web browser.

A digital image of the experimental rig is also available. After students aresatisfied with the results, they can eitherprint them out or e-mail the lecturer alaboratory report with the necessary plotsobtained from the Web browser.

Several tools have simplified thedevelopment of such interactive laboratoryexperiments. These include Ispy, ActiveXcontrol pad, Visual Basic Control CreationEdition, Internet control components, andNational Instruments ComponentWorks.

Preparing Experiments forUse over the InternetIt is possible to develop the experimentsdescribed in this article by building theActiveX component using Visual BasicControl Creation Edition software and Preparing the OCX for Internet download.

Building ActiveX Componentfor DownloadVisual Basic Control Creation Editionprovides the platform for creating thenecessary ActiveX OCX. Preparing thiscomponent is now simplified by usingComponentWorks by National Instruments.User interface components, such as switchesand sliders, are provided. Thus, the only taskrequired is to prepare Visual Basic scripts.Once the OCX is compiled, we are ready todistribute experiments over the worldwide Conducting an Experiment over the Internet

Preparing this component is now

simplified by ComponentWorks by

National Instruments. User interface

components, such as switches

and sliders, are provided. Thus,

the only task required is to prepare

Visual Basic scripts.

CUSTOMER SOLUTIONS


use a PCI-GPIB board to control andmonitor a 635 nm diode laser. To display live pictures from the lab, we used theIMAQ PCI-1408 board to digitize theanalog video signal from a standard camera.Our existing motion control system, basedon National Instruments LabVIEW,automatically controls camera motion.

System SoftwareWe first developed software libraries forinstrument control, data acquisition, andanalysis using LabVIEW. We also usedIMAQ Vision for G to provide image-processing libraries such as a Fast FourierTransform (FFT) routine to speed-updevelopment of live data analysis software.

After we tested the experiment on site,we developed Web-based access thatprovided users access to remotely monitorand control the lab set-up in real time. Weused National Instruments Internet Toolkit,with HTTP Server software, to process theuser requests from Web browsers. The Serveralso provides a configuration utility toimplement secured access to the experiment.Live image acquisitions as well as instrument

by Lambertus Hesselink, Ph.D, Professor,Dharmarus Rizal, Research Associate, Eric Bjornson, Ph.D, Post-Doctoral Fellow,Stanford University

The Challenge: Providingstudents with an Internet-controllable laboratory to assist in learning complex physicalprocesses through distance learning.The Solution: Creating Cyberlab,a Web-based laboratory, whichincorporates National InstrumentsLabVIEW, IMAQ, and GPIB boards.

IntroductionDistance learning is an exploding field,driven by the Internet revolution. However,a key component of current distancelearning implementations in science andengineering is missing – distance laboratoryexperimentation. Classical laboratoryteaching programs are costly, therefore wedeveloped this new laboratory environmentas a means of lowering staffing and trainingcosts, keeping up with technology, andmaintaining laboratory usage.

CyberLab addresses these issues, andprovides an innovative solution for sharing of resources among institutions. It providesstudents access to the laboratory fromanywhere, at anytime at a substantiallyreduced cost. We have created a full-scaleimplementation of a physical laboratoryusing National Instruments software andhardware tools. Although we have chosen an optical experiment in this pilot program,the concept of CyberLab lends itself forexperimentation in almost any field,including but not limited to engineering,physics, biology, chemistry, medicine, andmaterial and earth sciences.

The CyberLab interface provides a labscheduler, reference library, course material,computer-based analysis tools, testingfacilities, and a lab notebook – the keyconcept of the laboratory. It provides theclassical functions of data recording and notetaking and acts as a central repository of datadescribing the student’s progress in thelaboratory, the results of tests, data obtainedduring the course of the experiment,correspondence with the teachers andassistants, as well as a complete history of all steps taken by the student. Teacherscan also use the notebook to efficientlyevaluate the students’ performance and as a tool for organizing and managinglaboratory information. However, without the hardware and software fromNational Instruments we would not havebeen able to integrate this complex set offunctions into a seamless CyberLab program, and complete this phase of theproject in the allotted nine months.

System HardwareThe system is implemented using a standard 300 MHz Pentium II PC. We

CyberLab provides a novel,

cost effective paradigm for

distance learning with National

Instruments tools.

Education■ GPIB■ IMAQ■ LabVIEW

CyberLab, A New Paradigm in Distance Learning

An Optics Experiment Viewed and Controlled Using a Web Browser

CUSTOMER SOLUTIONS


For more information, please contact Professor Lambertus Hesselink, Stanford University, Room 353 Durand,Stanford, CA 94305-4035, tel 650-723-4850. e-mail [email protected], or Web cyberlab.stanford.edu

front panels transmit continuously to theuser browser at a rate of one frame persecond, and users can monitor experimentsin real-time over the Internet.

CyberLab provides a novel, cost-effectiveparadigm for distance learning. Studentsexpressed that they increased theirunderstanding of errors, and they reactedpositively to the usage of the remotelaboratory environment. They agreed thatthe remote laboratory experiment helped to illustrate concepts learned in class.Students found the remote laboratory aneffective tool for enhancing their knowledgeof optics and their understanding of thecourse material and the physical world.1

Students found the remote

laboratory an effective tool for

enhancing their knowledge of optics

and their understanding of the course

material and the physical world.

CUSTOMER SOLUTIONS


More recently, computer networks have become a driving force addressingclient-server dynamics and network services. The traditional way to support learning and training activities and to produce, anddistribute learning materials changed, andthe concept of “virtual classroom” wasintroduced. Teachers make availabledidactical material on the network and guide the learning process using electroniccommunication tools. The virtual approachis suitable for distance learning, continuingeducation, and professional training and canencompass the entire learning process.

Our work extends the virtual approachbeyond the distribution of didacticalmaterial to provide practice opportunitiesremotely. A virtual laboratory, to practiceinstruments and to conduct experimentsaddressed to the knowledge of measurement

methods, plays a significantrole in the learning processof electronic measurement and test.

The term “virtuallaboratory” refers to arepresentation of thelaboratory that isdistributed on the networkand provides access to andcontrol of real laboratoryinstrumentation andsoftware simulation.

Virtual instrumentationhelps to meet the challengein a timely and cost-effective manner. Moreovervirtual instrumentation

systems dramatically reduce the timerequired to develop complex test programsand unify the separate worlds of test andmeasurement and industrial automation.

The proposed approach provides thefollowing advantages:

• Students (users) can remotely operate laboratories

• Laboratory instruments are used by more than one person at a time

• Students “design” their own experiment • High-cost instruments are shared by

many researchers • Incomplete use of resources is avoided

both in academic and industrial sites• Virtual laboratories become part of

distance learning curricula, with all the related advantages

• Standardization of course/laboratories format can ease authoring and enlarge the availability of teaching/training material.

The Electronic Test BenchWith the ETB students practice withinstruments and execute measurementexperiments on electronic circuits throughthe Web. Students receive an introduction to the virtual laboratory, a set of on-lineinstrument manuals, and a set of experiments/lessons leading to gaining knowledge ofinstruments and measurement procedures.

Each lesson has a didactical target andoffers a collection of exercises using virtualinstruments. Hypertext guides the student

by Andrea Bagnasco, Marco Chirico, Walter De Michelis, Alan Rossi, and Anna Marina Scapolla, Department ofBiophysical and Electronic Engineering,University of Genoa, Academic andIndustrial Training

The Challenge: Supporting theincreasing demand of distance andcontinuous education on electronicsthrough the remote access to anelectronic instrumentationlaboratory on the net.The Solution: Designing andimplementing an interactive Web-based environment, the ElectronicTest Bench (ETB), consisting ofvirtual instruments and guidedexperiments on basic circuits to create a virtual laboratory.

AbstractTelematics and new programmingtechnologies support the increasing demandof education and training leading to thedelivery of computer-based learning systemsopen to distance and continuing education.

Using LabVIEW and InternetDevelopers Toolkit, we designed andimplemented an interactive learningenvironment for practice on electronicmeasurement methodologies. Theenvironment provides remote access to realand simulated instrumentation and guidedexperiments on basic circuits.

The environment is applied to theeducation on electronics during engineeringgraduation curricula.

IntroductionThe exponential development and diffusionof information technologies of the last fewyears have produced a considerable amountof research and activity in the field ofcomputer-based education aimed at:

• The enhancement of effectiveness of the learning process

• Multimedia educational material for high-quality training programs

• The improvement of methods and techniques for the “open” distribution of training material and the interoperability of resources.

Networking/University/Education■ GPIB■ Internet Developers Toolkit■ LabVIEW

Electronic Instrumentation Laboratories on the Net

The term “virtual laboratory”

refers to a representation of the

laboratory, that is distributed on

the network and provides access to

and control of the real laboratory

instrumentation and experiences,

via student software simulation.

An ETB Session

CUSTOMER SOLUTIONS


Conclusions The ETB takes advantage of the newfeatures of LabVIEW and InternetDevelopers Toolkit, optimizing thedistribution on the network of theinstruments’ interfaces and creating asuccessful virtual laboratory that is an asset to almost any electronics distant and continuous education program.

AcknowledgementThe authors thank Andrea Cambiaso and Alessandro Lugli from SITEM Srl fortheir helpful suggestions and support to the project.

For more information, contact Andrea Bagnasco, Marco Chirico, Walter De Michelis, Alan Rossi, or Anna Marina Scapolla, Department ofBiophysical and Electronic Engineering,University of Genoa,Via All’Opera Pia 11/A – 16145 Genoa, Italy,tel +39 10 3532267, fax +39 10 3532175,e-mail [email protected] www [email protected]

to connect test circuits to the instrumentsand stimulate them with known signals inorder to analyze the answers.

So far, a waveform generator and anoscilloscope were developed. The studentstarts the instruments panels, pressesbuttons, rotates knobs, and sees the resultsof these actions on the screen as if he/shewas acting on real instruments. Using thecontrol panel of the waveform generatorstudents can view different kinds ofwaveforms and the variation of waveformparameters like amplitude, frequency, offset, and duty-cycle. Similarly, with theoscilloscope interface, students visualize oneor both channels, and set various parameterssuch as the time scale, amplitude, verticaland horizontal shift, trigger setting, andscreen brightness.

A Look Inside the ETBThe ETB consists of three macro-blocks:

• The Web site• The ETB server• The ETB clients

The Web site delivers hypertexts andvirtual instrument panels. We installed a G Web server, which is an HTTP serversupplied with Internet Developers Toolkit.The Web also provides tips for the client’s configuration.

The ETB server consists of theinstruments’ drivers and simulators of thecircuits under test (Unit Under Test –UUT). The instruments’ drivers andsimulators are independent softwaremodules and communicate by means ofglobal variables. Each instrument driverreceives input commands from the clientsand then simulates the real instrumentbehavior. These commands are formulatedaccording to the IEEE 488 Standard; in this way, we can reuse the same softwaremodules both for real instruments controland for simulation.

The ETB clients are distributed on the net. They run the instruments and UUT interfaces; the instruments’ frontpanels are characterized by a strong realismand obtained by a heavy customization of LabVIEW basic elements. Thecommunication between the students and the server has been realized using the “VI server” features, and in particular usingthe “call by reference node” function, withwhich we set the communication throughTCP/IP in an easy and functional way.1

The ETB takes advantage of the

new features of LabVIEW and

Internet Developers Toolkit,

optimizing the distribution on

the network of the instruments’

interfaces and creating a successful

virtual laboratory that can be an

asset to almost any electronics distant

and continuous education program.

The ETB Model

CUSTOMER SOLUTIONS


history by sending the correspondingcommands to the servomotors of the ATM.The VI could easily be modified to specifyany deformation history composed of axial and rotational motions.

Designing a Remote Mechanicsof Materials ExperimentWe used an ATM controlled by LabVIEW and DataSocket to conduct a remote experiment. During the first pilot test, students ran tests in successionusing a single client computer. We designed a VI example that would repeatimmediately after a test run by specifying a single cycle loading history. We attachedthe specimen once by an operator andloaded the specimen cyclically as manytimes as needed. The operator selected themaximum displacement of the cross-headand also the cross-head speed for a tensiontest. After setting these two parameters, thestudents executed the experiment from the client computer in the classroom. The students plotted the data points on the screen concurrently with the motion

by Carlos L. Yapura, Richard Griffin,Dimitris C. Lagoudas, Research Associate,Professor, Texas A&M University

The Challenge: Developingremote experiments via the Internetthat demonstrate the mechanics ofmaterials taught to students who donot have access to a laboratory facility.The Solution: Using LabVIEWwith DataSocket to create virtualinstruments (VIs) that access atension/compression/torsion testframe via the Internet.

IntroductionWe developed experiments pilot-tested to sophomore-level engineering students at Texas A&M University as part of the NSF Foundation Coalition effort torestructure engineering courses. Thecourses, taught to a large number of theengineering students, have significant timeconstraints, therefore the timely executionof these labs is of primary importance.Using LabVIEW, students remotely rantension tests and obtained data in a time-efficient manner.

Controlling the Testing MachineWe developed experiments using anadelaide testing machine (ATM), equippedwith computer controlled loading and data acquisition. The ATM is capable ofpulling specimens in tension, torsion, and compression and is controlled by apersonal computer through two XT-typecards. We used LabVIEW to customize a test according to an experiment and created a VI that specified a deformation

Networking/University/Education■ DataSocket■ LabVIEW

Mechanics of Materials Experiments Via the Internet

We used LabVIEW to customize

a test according to an experiment

and create a virtual instrument

(VI) that specified a deformation

history by sending the corresponding

commands to the servomotors of

the ATM.ATM Test Frame Used for Tension,Compression, and Torsion Tests

A Team of Students Performing a Remote Tension Test

CUSTOMER SOLUTIONS

of the servomotors. They viewed a videostream of the current experimental setup to obtain a feedback of what was physicallyhappening in the lab.

ResultsThe class completed testing in less than half the time required for traditionalexperimentation. In the future, we canincrease efficiency by using the variousclient/server features of DataSocket inclassrooms. The technical support receivedfrom National Instruments for theimplementation of DataSocket wasextremely helpful during the developmentof this test. We successfully delivered thefirst pilot test as a result of the combinedefforts from the Foundation CoalitionTeam at Texas A&M University andNational Instruments.1

For more information contact Carlos Yapura, Texas A&M University, 1775 George Bush Drive West, College Station, TX 77845tel (409) 845 -1028, fax (409) 845 - 8191

Control Panel in LabVIEW Used for the Remote Tension Tests

Using LabVIEW, students

remotely ran tension tests

and obtained data in a time-

efficient manner.

© Copyright 2000 National Instruments Corporation. All rights reserved. Product and company names listed are trademarks or trade names of their respective companies. 080300

Branch Offices: Australia 03 9879 5166 • Austria 0662 45 79 90 0 • Belgium 02 757 00 20 • Brazil 55 011 284 5011 • Canada 905 785 0085 • China 0755 3904939Denmark 45 76 26 00 • Finland 09 725 725 11 • France 01 48 14 24 24 • Germany 089 741 31 30 • Greece 30 1 42 96 427 • Hong Kong 2645 3186 • India 91805275406Israel 03 6120092 • Italy 02 413091 • Japan 03 5472 2970 • Korea 02 596 7456 • Mexico 001 800 010 0793 • Netherlands 0348 433466 • New Zealand 09 914 0488Norway 32 27 73 00 • Poland 0 22 528 94 06 • Portugal 351 1 726 9011 • Singapore 2265886 • Spain 91 640 0085 • Sweden 08 587 895 00 • Switzerland 056 200 51 51Taiwan 02 2528 7227 • U.K. 01635 523545 • Venezuela 800 1 4466

(512) 794-0100 • Fax (512) 683-9300 • [email protected]/academic/distance_learning.htm

Distance Learning Solutions Guide - National Instruments · Distance Learning Solutions Guide ......

Documents

Transcript of Distance Learning Solutions Guide - National Instruments · Distance Learning Solutions Guide ......