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1. IVI Configuration Server I O Library Instrumentation Hardware IVI Configuration Store Chapter 11 The IVI Configuration Store holds information about the IVI drivers installed on your computer and configuration information for your instrument system By providing a way to flexibly reference and configure IVI drivers and instrument I O connections outside of your application the IVI Configuration Store makes interchangeability possible Consider an application in which you use a specific driver to communicate with a specific instrument model at a fixed location Change anything the driver the model the location and you have to modify the application to accommodate that change That s when the Configuration Store comes into play An IVI Configuration Store offers the capability to work with different instrument drivers models or locations without having to modify your application You can imagine how useful this can be when using a compiled application that you cannot easily modify The IVI Configuration Store contains data that describe the software modules used to control the instruments the hardware assets that perform measurement or stimulus functions the driver session that associates the software and hardware and the logical name that lets you point to a specific session SoftwareModule A SoftwareModule provides information about a particular instrument driver software component that is installe
2. 0 000 e eects 65 Example Requirements 0 cece eee eee eee 65 Download and Install the Driver 0 0 0 cece eee eee 65 Data Soue E ener ere or eon er ee re 66 Control Source eee eens 68 Data SHAK CMT 70 Compile and Run 0 0 0 ccc esses 70 Close SESSION cate e ast ice Re a etre Gua a wea ape e A o 70 Further Information llli 70 Using IVi with PAWS a cesserexessatkesaeP REPE PRERESE RR RE 73 The Environment 0 000 cece eee eee eee 73 Example Requirements 0 0 cee cece eee eee eee 73 Download and Install the Driver 000000 cece eee 73 Chapter 9 Chapter 10 Prepare the PAWS Environment 0 0 00 cece eee eens 74 Add the WCEM Interface Functions 0 0200c ee eeae 76 Connect to the IVI COM Driver 0 0000 cece ens 77 Build the Project leise 82 Prepare the Run Time System Environment 0065 82 Load and Run the Project 83 Further Information llle 83 Using IVI with Visual Basic 6 0 0 ccc cece eee eee ees 85 The Environment 2020 eee ee 85 Example Requirements 0 cece eee eee eee eee 85 Download and Install the Driver 0 0 00 c eee eee eee 85 Create a New Project and Reference the Driver 85 Adda BUON ue seu su RAE xU UE Sas uis x qan edad 86 Create an Instance of the Driver liliis 87 Initialize the Instrument
3. In 1993 the VXlplug amp play Systems Alliance created specifications for instrument drivers called VXIplug amp play drivers Unlike SCPI VXlp ug amp play drivers do not specify how to control specific instruments instead they specify some common aspects of an instrument driver By using a driver you can access the instrument by calling a subroutine in your programming language instead of having to format and send an ASCII string as you do with SCPI With ASCII you have to create and send the instrument the syntax MEASURE VOLTAGE DC then read back a string and build it into a variable With a driver you can merely call a function called MeasureDCVoltage and pass it a variable to return the measured voltage Although you still need to be syntactically correct in your calls to the instrument driver making calls to a subroutine in your programming language is less error prone If you have been programming to instruments without a driver then you are probably all too familiar with hunting around the programming guide to find the right SCPI command and exact syntax You also have to deal with an I O library to format and send the strings and then build the response string into a variable The VXIplug amp play drivers do not provide a common programming interface That means programming a Keithley DMM using VXIplug amp play still differs from programming an Agilent DMM For example the instrument driver interface for one m
4. xX ConsoleApplicationt Program v 3 Main string args v B using System 71 using System Collections Generic using System Text using Agilent A gilent34401 Interop g namespace Console pplicationi a class Program e static void Main string args gilent34401Class dmm new Agilent34401Class dmm Initialize A void Agilent34401 Class Initialize string ResourceName bool IdQuery bool Reset string OptionString ution E K Properties Configure the Instrument To set the range to 1 5 volts and the resolution to 1 millivolt type dmm DCVoltage Configure 1 5 0 001 Set the Trigger Delay To set the trigger delay to 0 01 seconds type dmm Trigger Delay 0 01 Set the Reading Timeout Display the Reading Create a variable to represent the reading and display the reading 1 Type double reading 2 To trigger the multimeter and take a reading with a timeout of 1 second type reading dmm Measurement Read 1000 3 Type Console WriteLine The measurement is 0 reading 4 Type Console ReadLine Close the Session To close out the instance of the driver to free resources type dmm Close Using IVI with Visual C and Visual Basic 33 34 Your final program should contain the code below using System using System Collections Generic using System Text using Agilent Agilent34401 Interop namespace ConsoleApplicationl class Program static v
5. gt Select Object From Type Library Type Library IVI Agilent34401 Agilent Technologies 1 1 Type li Browse Librarv Version 1 1 Objects Show Creatable Objects Only c Agilent34401 Agilent34401 Agilent34401 1 A 3 IAgilent34401AC IAgilent34401ACCurrent IAgilent34401ACVoltage IAgilent34401Advanced IAgilent34401Calibration v Initialize the Instrument 1 From the View menu select Class Browser The Class Browser allows you to invoke methods and set or get properties of the ActiveX COM object 2 From the Object library drop down select ActiveX and then Select Type Libraries 3 Scroll down and select the IVI Agilent 34401A Agilent Technologies 1 1 Type Library Version 1 1 Click OK Chapter 4 4 5 Back in the Class Browser under Properties and Methods scroll down and select Initialize Click Create and drag the Invoke Node to the Block Diagram Create constants and enter values for ResourceName IDQuery Reset and OptionString e GPIBO 23 INSTR in the instrument ResourceName field False in the IDQuery field True in the Reset field Simulatez1 in the OptionString field Connect the automation refnum and error terminals from Automation Open to Initialize Invoke Node Note Instead of using the Class Browser you can select an Invoke Node from the ActiveX subpalette and select the Initialize method To access driver properties you can select a Property Node f
6. 3 Tosetarange of 1 5 volts and resolution of 1 millivolt enter the following in the Edit Configure dialog box e 1 5 in the Range field 0 001 in the Resolution field 4 Click OK Set the Trigger Delay 1 Double click to add another operation The Select an Operation dialog box appears 2 Expand the treenode Trigger and select Delay Click Set The Edit Delay dialog box appears 3 Toseta trigger delay of 0 01 seconds enter 0 01 in the delay field 4 Click OK Set the Reading Timeout 1 Double click to add another operation The Select an Operation dialog box appears 2 Expand the treenode Measurement and select Read Click OK The Edit Read dialog box appears 3 To take a reading with a timeout of 1 second enter 1000 in the MaxTimeMilliseconds field 4 Click OK The To From myDMM object includes an additional output node labeled return This will hold the value returned from the Read Measurement operation Using IVI with Agilent VEE Pro 97 98 Close the Session Display the Reading 1 Tips Chapter 10 Now that you have completed all of the driver operations you should close the driver session to free resources 1 Double click to add another operation The Select an Operation dialog box appears 2 Select Close to release all resources associated with the simulated Agilent 34401 Click OK agilent34401 Class Createlnstance Agilent Agilent34401 Interop Agilent Agilent344 agilent34401 Class
7. import GlobMgr dll no namespace Se db db db ook import Agilent34401 dll no namespace int IVI Demo HRESULT hr hr CoInitialize NULL if FAILED hr Using IVI with Visual C eoeeene N _ exit 1 IAgilent34401Ptr dmm uuidof Agilent34401 kEryi dmm Initialize GPIB 23 false true simulate true dmm DCVoltage Configure 1 5 0 001 dmm Trigger Delay 0 01 double reading dmm Measurement Read 1000 wprintf L Reading g n reading catch _com_error e wprintf L Error s n e ErrorMessage dmm gt Close CoUninitialize return 0 Build and Run the Application Build your application and run it to verify it works properly 1 From the Start Menu select Build and click Build IVIDemo 2 From the Start Menu select Debug and run the application Using IVI C in Visual C The following sections show to get started with IVI C in Visual C Create a New Project and Import the Driver Type Libraries To use an IVI C Driver in a Visual C program you must provide paths to the header files and libraries it uses 1 Launch Visual Studio 2005 and create a Win32 Console Application in C with the name IVI demo Note The program already includes some required code including the header file include stdafx h 22 Chapter 2 Options Environment Platform l Show directories for Performance Tools Win32 Library
8. l l eee 87 Configure the Instrument 88 Set the Trigger Delay 0 0 0 89 Display the Reading 89 Close the Session iiisiiiisesllseesesese eee 89 Ho RECO gia eee eee Yee ete do ee dot Sey 90 Further Information 00 0 0 cece ete tee ete eee 91 Using IVI with Agilent VEE Pro Lesser 93 The Development Environment 00 0 araara 93 Example Requirements 0c eee eee eee eee 93 Download and Install the Driver 0 0 cece eee ee 93 Launch the Instrument Manager and Select the Driver 93 Create an Instance of the Driver 0 000 cece eee eeee 95 Initialize the Instrument 00 000 96 Configure the Instrument 97 Contents Contents Chapter 11 Set the Trigger Delay 0 0 eens 97 Set the Reading Timeout 0 0 0 e eee eee 97 Close the Session 0000 eee eee tent e eee 98 Display the Reading 0 0 cece ee eee eee eee 98 ocn 98 Another Method to Display the Reading 98 Further Information llis 99 Advanced TOPICS 2cdsu kk enu ki DES a RW AMETE Rad b do oar 101 IVI Architecture lesse RR II 101 Driver API m 101 Driver Types oraaa eter E e a gente aie a A ees 102 Instrument I O lississsssssssse II 104 Shared Components 0 00 cee eee cece teenies 104 Interchangeability 0 0 0 cece eee 104 IVI Configuration Store 2 tees 106 VECOM s
9. IVI COM DMM Mae ia a 9 To add anew h file called DMM h to include the code necessary to reference the driver header files and librairies right click on the WCEM module 10 Select Add New File to Module The New dialog appears 11 Select CEM header file and check Add to Project 12 Enter DMM in the File Name field Click OK Connect to the IVI COM Driver 1 From the PAWS Project window select the DMM h file Insert the following code in the DMM h file ifndef DMM h define DMM h include lt atlbase h gt include Visacom_i c import IviDriverTypeLib dll named_guids raw_interfaces_only raw_native_types no_namespace Using IVI with PAWS 78 Chapter 8 import IviDmmTypeLib dll named guids raw interfaces only raw native types no namespace import Agilent34401 dll named guids raw interfaces only raw native types no namespace endif Note This header file allows access to the COM IVI specific and device environments From the PAWS Project window select the ctrl cpp file Insert the following code in the ctrl cpp file directly below include key h code include DMM h extern CComPtr IAgilent34401 driver extern CComPtr IAgilent34401DCVoltage pDMMDCVolt extern CComPtr IAgilent34401Trigger pDMMTrig extern CComPtr IAgilent34401Measurement pDMMData extern HRESULT hr From the PAWS Project window select the DMM cpp file Insert the fol
10. Option Explicit Dim dmm As New Agilent34401 Private Sub btnTest Click dmm Initialize GPIB 23 False True Simulate True dmm Function Agilent34401FunctionDCVolts dmm DCVoltage Configure 1 5 0 001 dmm Trigger Delay 0 01 lblResult Caption dmm Measurement Read 1000 dmm Close End Sub Using IVI with Visual Basic 6 0 eccccc co e 90 Tips Chapter 9 Project1 Formi Form a Projecti Formi Code Properties Form1 Option Explicit Dim dmm As Nev Agilent34401 Private Sub btnTest Click dmm Initialize GPIB 23 False True Simulate True dmm Function Agilent34401FunctionDCVolts dmm DCVoltage Configure 1 5 0 001 dmm Trigger Delay 0 01 lblResult Caption dmm Measurement Read 1000 drm Close End Sub M Returns the name used in code to identify an The Agilent 34401 driver conforms to the IviDmm class so you can easily write your program to use the class compliant interfaces instead of the instrument specific interfaces You will need to add a Reference to the lviDmm Class Type library for your project to compile Here is the code Option Explicit Dim dmm As New Agilent33401 Dim ividmm As IIviDmm Private Sub btnTest Click Set ividmm dmm ividmm Initialize GPIB 23 False True Simu late True ividmm Configure IviDmmFunctionDCVolts 1 5 0 001 ividmm Trigger Delay 0 01 lblResult Caption ividmm Measurement Read 1000 ividmm Clos
11. Exclude directories CInstallDir athmFc lib i386 FrameworkSDKDirjlib vSInstallDir vSInstallDir lib c Program Files Ivijlib msc lt gt Library Directories Path to use when searching For library Files while building a C project Corresponds to environment variable LIB a Chapter 2 oc WN Launch Visual Studio 2005 and create a Win32 Console Application in C with the name IVI demo Note The program already includes some required code including the header file include stdafx h From the Tools menu select Options Expand Projects and Solutions then click on VC Directories Click on the Show directories for combo box and choose Library files Add the following two entries to your path The first entry will point to the default directory for IVI drivers This is typically C Program Files Ivi Bin The second entry points to the VISA DLL that many drivers require Initialize COM 1 VXIPNPPATH VisaCom Note These steps need only be done once for each computer you use All subsequent Visual Studio projects will continue to use these settings and will be able to locate your IVI COM drivers Click OK To import the type libraries type the following statements following the header file reference import IviDriverTypeLib dll no namespace import IviDmmTypeLib dll no namespace import GlobMgr dll no namespace import Agilent34401 dll n
12. Files Projects and Solutions General Build and Run Reference files vCInstallbir lib mx VB Defaults VCInstallbir atlmfciib Source files C Directories V CInstallDirjatlmFc lib i386 Exclude directories C Project Settings vCInstallDir PlatFormSDK lib FrameworkSDKDirjlib Source ais vSInstallDir Text Editor VSInstallbir lib DevPartner c Program Filesivillibimsc Business Intelligence Designers c Program Files Ivi Bin Database Tools Debugging lt f gt Device Tools T EEE HTML Desianer ibrary Directories is Path to use when searching For library Files while building a C project Corresponds to environment variable LIB E 6 EE 52005 200 2005 a Microsoft Office Keyboard Setting s amp From the Tools menu select Options Expand Projects and Solutions then click on VC Directories Click on the Show directories for combo box and choose Library files a fF WN Add the following entry to your Library files path This entry points to the default directory for IVI drivers This is typically c Program Files IVI Lib msc o Click on the Show directories for combo box and choose Include files 7 Add the following entries to your Include files path The first entry will point to the default directory for IVI drivers This is typically C Program Files IVI include The second entry points to the VISA header files that IVI C drivers req
13. Initialize GPIB0 23 INSTR False True simulate true agilent34401Class agilent34401Class DCVoltage Configure 1 5 0 001 el agilent34401 Class Trigger Delay 0 01 return agilent34401 Class Measurement Read 1000 agilent34401Class CloseQ Double Click to Add Operation lt To display the measurement from the Main Menu select Display and click AlphaNumeric Place the AlphaNumeric object on your workspace 2 Connect a wire from the return output terminal on To From myDmm to the input terminal of the AlphaNumeric object 3 Click F5 or the Right Arrow button on the toolbar to run the program The Display returns a simulated result Another Method to Display the Reading You can display the measurement in another way as well From the Main Menu select select Data Variable and click Declare Variable Declare a global variable named agilent34401Class with a Type Object and Sub Type NET Select Edit and in the Specify Object Type dialog select the following Agilent Agilent34401 Interop in the Assembly field Agilent Agilent34401 Interop in the Namespace field Agilent34401Class in the Type field Then delete the agilent34401Class output terminal You can now share this IVI COM object with other To From objects or formula objects in VEE This will let you use multiple objects for the same driver instance without creating all of your driver commands in one object Further Information Learn more about VEE P
14. Option Explicit Create a variable for the driver and initialize it with the New statement On the next line type Dim dmm As New Agilent33401 Initialize the Instrument Now you will enter the code that will execute when you click Test On the line after Private Sub btnTest Click type dmm Then type dmm Initialize GPIB 23 False True Simulate True Note As soon as you type the period Intellisense displays the possible methods and properties and helps ensure you use correct syntax and values Note From the Start Menu select View and click Object Browser to view the functions and parameters available in the instrument driver Limit the Object Browser to a specific library by selecting it in the top left list box Using IVI with Visual Basic 6 0 ee0ee0e8 u Object Browser Classes 9 lt globals gt a Agilent34401Apertur aP Agilent34401AutoZe eS eP Agilent34401dBmRe eP Agilent34401 ErrorCc aP Agilent34401Functio aP Agilent34401InputTe eP Agilent34401MathFu eP Agilent34401MeasC eP Agilent34401Resolu eP Agilent34401Samplt aP Agilent34401StatusF eP Agilent34401Statust d Agilent34401Trigger aP Agilent34401Trigger eP AlignConstants eP AlignmentConstants amp 9 AmbientProperties amp App eP ApplicationStartCon amp AsyncProperty DCCurrent 9 DCVoltage DCVoltageRatio 9 Display DriverOperation Frequency Function initialized S viDmm Math Measurement eS R
15. any IVI COM driver The Session Factory creates an instance of the driver and returns Advanced Topics 109 Chapter 11 a reference to the instance of the driver This line of code then casts the reference returned to type IlviDriver from which all of IVI s inherent capabilities can be referenced IIviDriver driver IIviDriver factory CreateDriver logicalName Initialize is required because the Session Factory does not take care of that function driver Initialize logicalName true true Identity is a property of IlviDriver that references the llviDriverldentity interface Identifier is a property of IlviDriverldentity interface that returns a string that identifies the driver string identifier driver Identity Identifier Print the string Console WriteLine Identifier 0 identifier liviDmm If we want the code to use multiple drivers that all support the DMM class and use the IVI DMM class interfaces we must modify it as shown below Note that only IVI COM drivers that implement the IVI DMM class will work with this program Create a string variable for logical name string logicalName LineVoltage Create an instance of the Session Factory IIviSessionFactory factory new IviSessionFactoryClass Set the type to match the referenced IVI Instrument Class for class interchangeability This code for IlviDmm uses the factory to create a driver based on the logical name LineVoltage In
16. driver for C but IVI C is also supported eccccc N e 30 Create a New Project and Reference the Driver Chapter 3 To use an IVI Driver in a Visual C program you must first add a reference to it Launch Visual Studio and start a new Console Application in Visual C Note The program already includes some required code including using statements Keep this required code Select Project and click Add Reference The Add Reference dialog appears Select the COM tab All IVI drivers begin with IVI Scroll to the IVI section and select IVI Agilent 34401 Agilent Technologies 1 1 Type Library Click OK Note If you have not installed the IVI driver it will not appear in this list You must close the Add Reference dialog install the driver and select Add Reference again for the driver to appear Add Reference NET COM Projects Browse Recent Component Name ISAFrdm 1 0 Type Library ISScriptHandler 1 0 Type Library IVI Agilent33220 Agilent Technologies 1 1 Type Library IVI Agilent34401 Agilent Technologies 1 1 Type Library IVI Agilent34410 1 0 Type Library IVI AgilentRFPowerMeter 3 0 Type Library Ivi Configuration Server 1 0 Type Library IVIAudioEffectX ActiveX Control module IVIAudioModeX ActiveX Control module IVIAudioSRSX ActiveX Control module IVIBookmarkX ActiveX Control module IVICaptureX ActiveX Control module IvIColorX ActiveX Control module IviDCPwr 2 0 Type Library TyTDi nlavX Active
17. examples of driver use 2 Several vendors include examples as part of driver installation For the Agilent 344014 driver from Agilent Technologies we use in some of the examples throughout the guide a folder located at C Program Files IVI Drivers Agilent 34401 Examples contains examples that show its use in a variety of different environments Finally contact your driver vendor for help Even if the vendor hasn t published examples online or included them during installation they may have samples that you can use to build a program Advanced Topics ecc cc 13 114 Chapter 11
18. how to use an IVI C driver in LabVIEW and second how to use an IVI COM driver in LabVIEW Note The functionality shown in the example is available in a LabVIEW example supplied with the IVI driver from National Instruments Using IVI C Alll IVI C drivers provide a Dynamic Link Llbrary DLL interface While LabVIEW provides the Call Library Function node to call DLLs many IVI C drivers also come with a LabVIEW wrapper that provides the familiar Vl interface to the driver s 38 functions making it easier to use in LabVIEW If your IVI C driver does not have a LabVIEW wrapper you can create one using a free tool by clicking on LabVIEW Instrument Driver Import Wizard at http www ni com devzone idnet development htm Note The functionality shown in this section is available in a LabVIEW example supplied with the IVI driver from National Instruments Create a Project and Access the Driver Chapter 4 1 2 3 Launch LabVIEW From the File menu select New VI The Front Panel and Block Diagram appear Right click in the Block Diagram The Functions palette appears Select the Instrument I O subpalette and then the Instrument Drivers subpallete You can access all instrument driver VIs from this palette Click Instrument Drivers Select hp34401a from the palette Select the hp34401a IVI driver from the palette Note If the driver you want to use is not listed download and install the driver and close and restart LabV
19. i f IVI FOUNDATION Getting Started Guide Your Guide to Getting Started with IVI Drivers Revision 1 0 Chapter 1 Chapter 2 Contents ecc ipu PRICPI M 9 Purpose 4 toute moe ege Reden ba don Reade Band w cite ic Ma iced 9 Why Use an Instrument Driver liliis isle 9 VALER 10 Why Use an IVI Driver 00 0 0 6 00 cee 12 Flavors of IVI Drivers 0 0 eect tees 13 Shared Components 00 0 cece cece eee eee eee 13 Download and Install IVI Drivers llle 13 Familiarizing Yourself with the Driver 0 0c eee eaee 14 Examples usd at acdc eta yes ee i ate ete eal ee 14 Using IVI with Visual C 0 0 0 0 cece eee eee eens 17 The Environment 0 0c 17 Example Requirements 0c eee eee eee eee eee 17 Download and Install the Driver 0 0 0 0 cece eee eee 17 Using IVI COM in C annuau aaa 17 Create a New Project and Import the Driver Type Libraries 18 Initialize COM annn ete eee 19 Create an Instance of the Driver 0 0 ccc eee eee eee 19 Initialize the Instrument selesleeen BRA 20 Configure the Instrument liliis isses 20 Set the Trigger Delay 00 00 cece eee 20 Set the Reading Timeout Display the Reading 21 Error Checking 00 000 e cece e eet eee eee eee 21 Close the Session 000 c eee tte 21 Build and Run the Application 2 0 0 c eee e
20. line of code Type dmm Function Agilent34401FunctionEnum Agilent34401FunctionDCVolts To dimension a variable for the instrument and reading use Dim dmmand Dim reading Further Information e Learn more about Visual C at http msdn microsoft com vsharp Learn more about Visual Basic at http msdn microsoft com vbasic Microsoft and Visual Studio are registered trademarks of Microsoft Corporation in the United States and or other countries Using IVI with Visual C and Visual Basic 35 36 Chapter 3 Chapter 4 Using IVI with LabVIEW The Environment National Instruments LabVIEW is a graphical development environment for signal acquisition measurement analysis and data presentation LabVIEW provides the flexibility of a programming language with less complexity than traditional development tools Example Requirements LabVIEW 8 2 0 VI C Agilent 34401A IVI C specific driver Version 4 1 October 2006 from National Instruments VI COM Agilent 34401A IVI COM driver Version 1 1 0 11 March 2006 from Agilent Technologies Note These drivers may require an I O library to be installed Check the driver vendor s Web site for details Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it Since LabVIEW supports both IVI C and IVI COM drivers this example is written two ways first to show
21. not installed the IVI driver it will not appear in this list You must close the References dialog install the driver and select References again for the driver to appear Click OK The References dialog closes References Project1 Available References _ iPassSQMRecorder 1 0 Type Library 1 2 3 IPassSQMUploader 1 0 Type Library iPCAgent 1 0 Type Library ISAFrdm 1 0 Type Library ISScriptHandler 1 0 Type Library gilent33220 Agilent Technoloqi IVI Agilent34410 1 0 Type Library di eee cone 3 0 Type Library Note You must click OK for Visual Basic to accept the References however the software provides no confirmation You can verify the driver is available for use by opening the Add References dialog and viewing the checked references All checked references appear near the top of the list Click the Command Button in the Toolbox to create a button Drag the button to the form and drop it Change the Name property to btnTest and the Caption property on the Commandi button to Test in the Properties list at right Project Form1 Form Project1 Project1 6 Forms P3 Formi Form1 Properties btnTest Create an Instance of the Driver 1 Double click Test The Projecti Form1 Code screen appears Note that some code has already been added including Private Sub btnTest Click and End Sub To enable strong type checking at the top of the screen before the Private Sub line type
22. toolbox provides additional MATLAB functionality Example Requirements MATLAB R2007a MATLAB Instrument Control Toolbox Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it This example uses an IVI COM driver MATLAB also supports IVI C drivers Note Older versions of the Instrument Control Toolbox R2006b or earlier support only IVI instrument drivers that used the IDispatch interface IVI instrument drivers that use the IUknown interface only will not work with these versions To determine if the driver implements only the IUknown interface please consult the vendor LEN a N 58 Configure the IVI Driver Chapter 6 The Instrument Control Toolbox provides a graphical Test amp Measurement Tool that enables you to interact with instrument drivers and instruments without writing MATLAB code The Test amp Measurement Tool lets you configure IVI driver properties in MATLAB and store them in the IVI configuration store Note Learn more about the IVI configuration store in Chapter 11 Advanced Topics 1 At the MATLAB command line type tmtoo1 to launch the Test amp Measurement Tool GUI Or from the MATLAB Main Menu select Instrument Control Toolbox and click Test amp Measurement Tool The
23. utilities with your IVI driver instrument or ADE Important Never make changes directly to the Configuration Store file Instead use an IVI configuration utility or the IVI Configuration Store API The configuration server provides much more functionality than it is possible to describe here For more information see the IVI Configuration Server specification at htto ivifoundation org Downloads Specifications htm or contact your IVI provider Future Development of IVI One feature of IVI that gives it an advantage over other instrument drivers is simply that it s still actively evolving Current IVI work focuses on the following Keeping up to date with technology including 64 bit integers and Vista compatibility Keeping up to date with advances in test and measurement including LXI technology Developing new class specifications for digitizers counter timers and synthetic instruments Developing a NET standard that will optimize IVI drivers for use in NET IVI Drivers in Action Chapter 11 IVI Getting Started Guide contains a single example in many different ADEs You probably work primarily in a single ADE but would benefit from seeing other examples that use IVI drivers Examples are available from two primary sources Vendors who provide IVI drivers frequently show examples of their use in test applications on their Web site Visit the vendor s site and search for IVI drivers to find information on and
24. ESULT hr hr CoInitialize NULL if FAILED hr F exit 1 IIviDmmPtr dmm _uuidof Agilent34401 try dmm gt Initialize GPIB 23 false true simulate true drm gt Configure drm gt Trigger gt Delay 0 01 double reading dmm gt Measurement gt Read 1000 wprintf L Reading g n reading catch com error ej wprintf L Error sin e ErrorMessage dim Close t CoUninitialize lt Lill gt Set the Trigger Delay To set the trigger delay to 0 01 seconds type dmm Trigger Delay 0 01 Chapter 2 Set the Reading Timeout Display the Reading Create a variable to represent the reading and make a reading with a timeout of 1 second 1000 milliseconds 1 Type double reading dmm Measurement Read 1000 2 To display the reading use printf Type wprintf L Reading g n reading Error Checking To catch errors in the code activate error checking 1 Surround the preceding statements with a try block Add the following lines as shown in the illustration above try 2 Process errors in a catch block Type catch com error e wprintf L Error s e ErrorMessage Close the Session To close out the instance of the driver and free resources type dmm Close The final code should look like the following include stdafx h import IviDriverTypeLib dll no namespace import IviDmmTypeLib dll no namespace
25. IEW The driver should now appear in the palette The driver palette allows you to browse the various VIs and functionality supported by the driver 1 1 Demo I 1 C vi Block Diagram ET amp X m gj Dialog amp User Wavelorm Agglcation C mP Laad Ge s Syndhronzebon Graphics amp 50 Report Gener y AOT Control Design 6 Smaticn Sgneseess ES 3 e Express 1 VISA Agiet 440 gO Initialize the Instrument 1 Select Initialize With Options VI from the hp34401a palette and place it on the Block Diagram IVI Demo IVI C vi Block Diagram File Edit View Project Operate Tools Window Help ple eu es bo Ff of 13pt Application Font 82 152 eA 2 Create constants and enter values for instrument resource name ID Query Reset and IVI option string e GPIBO 23 INSTR in the instrument resource name field e False in the ID Query field Truein the Reset field Simulatez1 in the Options field Note To create a constant control or indicator right click on the desired input terminal and select Create TM Using IVI with LabVIEW eoececee e 40 Configure the Instrument IVI Demo IVI C vi Block Diagram DER Ble Edit View Project Operate Tools Window Help a amp n9 es bale ot 13pt Application Font x a Simulate 1 6 GPIBO 23 INSTR v IdQuery GER Reset porig 1 From
26. LTS The initialize function refers to a logical name instead of the instruments physical address in this case SampleDMM vs GPIBO 23 INSTR In order to interchange a different DMM for the Agilent 34401A DMM you would update your configuration store to have the logical name SampleDMM point to the new instrument s Driver Session This is what the code for the example used in this guide would look like using and IVI C class driver static ViReal64 reading static ViSession session IviDMM InitWithOptions SampleDMM VI FALSE VI TRUE Simulate 1 amp session IviDMM ConfigureMeasurement session IVIDMM VAL DC VOLTS 1 5 0001 Advanced Topics 2h IviDMM ConfigureTrigger session IVIDMM VAL IMMEDIATE 0 01 IviDMM Read session 1000 amp reading printf f reading IviDMM close session Editing the Configuration Store If you installed the IVI Shared Components in the default location you will find the Configuration Store information in a file named lviConfigurationStore xml in C Program Files IVI Data Recent versions of Microsoft Internet Explorer can display xml files If you double click on the file a copy of Internet Explorer should start and you can view the contents of the file But we do mean view not edit you should use an IVI configuration utility or the IVI Configuration Store API to make changes to the Configuration Store file You can usually obtain these
27. Measure Foundry Install the driver and it appears in the list of available devices eoececee a c 66 Data Source Chapter 7 The property pages contain all the information necessary to create an instance of the driver initialize and configure the instrument set the trigger delay and reading timeout and close the instrument Launch Measure Foundry Select File and Click New The New Project screen opens In the Foundry window select All Components Enter IVI in the Search field A amp oN Select the LXI IVI Dmm component drag it to the Form and drop it Foundry Groups _ All Components Q Form Overview Me n ad All Components Search M Application Control M A Application Flow LXI LXI H Compound Contros wipCPowe IDR Connectivity Supply Custom Forms a Ez Data Acquisition i LX IXI Digital Filters BRE Display Components II Function Ivi g Graphics Generator Oscilloscope amp AM Instruments 210 LXI LXI oec OPC Process Control WIP IVI RF Sianal T 7 ower igna wA Processing Maler Generator LX LXI IVI Spectrum IVI Switch Analyzer 5 Double click the LXI component The Properties dialog appears Note The Properties dialog lets you access functions based on the purpose of your test 6 Configure the IVI DMM To initialize the DMM and setthe range to 1 5 volts and resolution to 1 millivolt enter the following In the Propertie
28. ROGRAM ENDS HERE LF c 999999 TERMINATE ATLAS PROGRAM IVI COM DMM To add a Device Database Module from the Main Menu select File and click New Module Select DEVICEDB and click OK To add a new file to the DEVICEDB Project Module from the Main Menu select File and click New File The New dialog appears Select DEVICE file Check the option to add the file to the project Enter dmm in the File Name field Click OK In the PAWS Project window select the file dmm ddb Insert the following code in the dmm dbb file and save it begin dev DMM cnx hi DMM Hi lo DMM Lo begin FNC 101 DC Voltage Measurement sensor voltage dc signal control Using IVI with PAWS 75 76 voltage range 300 v to 300 v continuous end DC Voltage Measurement end end dmm Note To understand the file contents refer to the Paws Studio online help 13 To build the project from the Main Menu select Build and click Rebuild All Add the WCEM Interface Functions The WCEM interface C functions are invoked by the ATLAS code These C functions include the IVI COM calls to control the instrument Chapter 8 1 From the Main Menu select File and click New Module The New dialog appears Select CEM and enter WCEM in the Module Name field Click OK From the Main Menu select View and click CEM Wizard The CEM Wizard dialog appears Click on the Advanced tab The CEM Wizard Advanced Settings dialog appea
29. Test amp Measurement Tool GUI opens 2 Inthe tree at left click the V node under the Instrument Drivers node 3 Selectthe Hardware Assets tab In the Hardware Assets dialog select Add and enter the following myDMM in the Name field This is my Agilent 34401 Digital Multimeter in the Description field optional e GPIBO 23 in the IO Resource name field Test amp Measurement Tool r Fie View Toos Help g lec Test 8 Measurement Instrument Control Toolbox gu rendeore Y instrument Objects 4E instrument Drivers E E MATLAB Instrument Drivers amp E vxipiugplay Drivers Cornhgur son store CA Program Mles IVIOataliviconfigu atonStore xml Logical Names Driver Sessions Software Modules Hardware Assets 4 Select the Software Modules tab The installed IVI drivers appear Note If you have not installed the IVI driver it will not appear in this list You must close MATLAB install the driver and restart MATLAB for the driver to appear 5 Select Agilent34401 from the drop down list The Software Modules dialog lists the module name supported instrument models and description Configuration store C Program Files I I Data IviConfigurationStore xml Logical Names Driver Sessions Software Modules Hardware Assets Physical names Descriots SCs sc Ix nulio Teva Sheahan Gece Next you must define your Driver Session to link the Software Module with the Hard
30. Using IVI with LabVIEW das adoes A PER PEE E ERO FERE eda 37 The Environment 20 020 37 Example Requirements lsleleleeeeeeeee 37 Download and Install the Driver llle lesen 37 Using IVG sos a a E a E E E E G Rh 37 Chapter 5 Create a Project and Access the Driver 000 0c eee 38 Initialize the Instrument 0 0 00 eee eee 39 Configure the Instrument liliis isses 40 Take the Reading 0 0 cece cece eee mh 40 Display the Reading 41 Close the Session 0000 cece cette eens 41 Add Error Checking n acte Re t canere n o 41 Run the Application llseleeee BB 41 Setting a Property in an IVI C Driver 020020 ee eee 42 Using IVI COM sssssssssssese RR m n 42 Create a Project and Access the Driver 000 00 cece 42 Initialize the Instrument 0 00 eee BRA 44 Configure the Instrument 0 06 0c esses 45 Take the Reading 2 202 eee eee eee 46 Display the Reading 0 cece eee 46 Close the Driver and Automation Sessions 46 Add Error Checking 000 ccc cece teeta 46 Run the Application 0 0 0 eee 47 Further Information llli 47 Using IVI with LabWindows CVI Lesser 49 The Environment enskuna naa nee 49 Example Requirements 0 cece ee eee eee eee eee 49 Download and Install the Driver 0 00 c ee
31. VI Demo IVI COM vi Block Diagram Eile Edit View Project Operate Tools Window Help amp e n 9 baaa 190 Application Font i fori SA Agilent34401Lib IAgilent34401 Bra en SI S TAgient34401 Dhe 9 TAgilent34401 SIS 9 Tagilent34401 cn uU Measurement Read I1 j 5 5 5 n E Initialize DCVoltage Configure P Trigger Delay IGPIB 23 INSTR ResourceName sp Range MaxTimeMilliseconds T IdQuery Resolution ooi T Reset ISimulate 1 OptionString Further Information Learn more about using an instrument driver in LabVIEW in this tutorial http zone ni com devzone cda tut p id 2804 TM Using IVI with LabVIEW 48 Chapter 4 Chapter 5 Using IVI with LabWindows CVI The Environment National Instruments LabWindows CVI is an ANSI C integrated development environment that provides a comprehensive set of programming tools for creating test and control applications LabWindows CVI combines the longevity and reusability of ANSI C with engineering specific functionality designed for instrument control data acquisition analysis and user interface development Example Requirements e LabWindows CVI 8 1 Agilent 34401A IVI C specific driver Version 4 1 October 2006 from National Instruments Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install
32. WS you must first prepare the PAWS environment 1 Launch PAWS Studio and create a new project In the New PAWS Project dialog enter a project name and directory for the project Click OK 2 To add a new file to the ATLAS Project Module from the Main Menu select File and click New File The New dialog appears 3 Select ATLAS file Check the option to add the file to the project 4 Enter atlas in the File Name field Click OK The atlas atl file appears New x Files Modes File Types E ATLAS file V Add to project Tz i TEXT file aus e Locabon Casp COM DMM ug gt 9 c 5 Insert the following code in the atlas atl file and save it 001000 BEGIN ATLAS PROGRAM IVI COM DMM 001010 REQUIRE DMM DC VOLTS SENSOR VOLTAGE DC SIGNAL CONTROL VOLTAGE RANGE 300 V TO 300 V MAX TIME RANGE 1 SEC TO 5 SEC CNX HI LO 74 Chapter 8 10 11 12 C 001110 DECLARE VARIABLE MEASURED IS DECIMAL C 02000 OUTPUT C LF ATLAS PROGRAM STARTS HERE LF C 002200 VERIFY VOLTAGE INTO MEASURED DC SIGNAL USING DMM DC VOLTS NOM 0 VUL 0 5 V LL 0 5 V VOLTAGE RANGE 0 5 V TO 0 5 V MAX TIME 5 SEC CNX HI X20 2 LO X20 3 002300 OUTPUT C DC VOLT MEASUREMENT 1 MEASURED C VDC C 999000 OUTPUT C LF ATLAS P
33. X Cantral made lt Note The program looks the same as it did before you added the reference but the driver is now available for use To see the reference select View and click Solution Explorer Solution Explorer appears and lists the reference Create an Instance of the Driver To allow your program to access the driver without specifying the full path type the following line immediately below the other using statements using Agilent Agilent34401 Interop Note As soon as you type the A for Agilent IntelliSense lists the valid inputs Program cs StartPage M 3 Eusing System using System Collections Generic using System Text tusing Agilent Agilent34401 E namespace C i ioni class Program static void Main string args es a Congratulations You may now write the program to control the simulated instrument Note To view the functions and parameters available in the instrument driver right click the library in the References folder in Solution Explorer and select View in Object Browser Using IVI with Visual C and Visual Basic 31 32 Program cs Start Page Object Browser X Seari Browse All Components vade Haz ch X x art Utiity 5 amp 3 Aglent Agilent34401 Interop A IviDri Ident _ Descripti Eo Agilent34401 R Ilvbriverldenti 7 oye E a Aglenk34401ApertureTimeUni F tlviDriverIdentity Vendor amp 39 Agilent34401AutoZeroE
34. and enter DC Volts from the drop down list in the Measurement Function field 1 5 in the Range field 0 001 in the Resolution field and session in the Instrument Handle field Sil c uVI Derno VI Demo cws HP 344014 Digital Multimeter Configure Measurement Fle Ect Yew Code Bad Bun jnstrument iray Took Window Options Hep lt l x BeBe bs 5s 3 ELS s IVI Demo al Source Files EJM Omec gt Inshumernt Fies Fo34401a fp Measurement Funcion Range JOC Vers 1 5 j C Lixanes Resolubon bel E Instruments y HP 344014 Dipal Mutat o 001 E n BH intwenOptons D Conhguabon Bl Contig seMeasucemer Measusemert Oporad irni H Conhgasson intomet DEM E SeUGeuCheck Altis session nes lt e E an 3 Select the Code menu and click Insert Function Call to insert the function and values into your program Close the function panel The hp34401a_ConfigureMeasurement function appears in your program 4 From the library tree select Configuration select Trigger and click ConfigureTrigger The Configure Trigger function panel opens 5 Set the trigger source to immediate the trigger delay to 0 01 seconds and the instrument handle to session Select and enter Immediate from the drop down list in the Trigger Source field 0 01 in the Trigger Delay field session in the Instrument Handle field 6 Select Code and click Insert Function Call to insert
35. and free resources type If session hp3440la_Close session The final code should contain the code below Kinclude stdafx h include hp34401a h ifndef checkErr define checkErr fCall if error fCall error error 0 error VI SUCCESS goto Error ls rror error Chapter 2 endif int main int argc _TCHAR argv iSession session E n n V ViStatus error VI SUCCI V iReal64 reading checkErr hp3440la_InitWithOptions GPIB 23 INSTR VI FALSE VI TRUE Simulate 1 amp session checkErr hp34401a ConfigureMeasurement session HP34401A VAL DC VOLTS 1 5 0 0001 checkErr hp34401a ConfigureTrigger session HP34401A VAL IMMEDIATE 0 01 checkErr hp34401a Read session 1000 amp reading printf Reading f reading Error if error VI SUCCESS ViChar errStr 2048 hp34401a GetError session amp error 2048 errStr printf Error errStr if hp34401a hp34401a close hp34401a Build and Run the Application Build your application and run it to verify it works properly Using IVI with Visual C LUNO N A 28 1 From the Start Menu select Build and click Build IVI Demo 2 From the Start Menu select Debug and run the application Further Information Learn more about Visual C at http msdn microsfot com visualc Mi
36. anel Driver IVI COM Driver Session Name i Agilent34401 M em Agilent33220 Parameters to init call Agilenta4401 Address e g GPIBO 12 INSTR Agilent34410 v Perform Identification Query AgilentRF PowerMeter DMM Session Name v Perform Reset Unknown pite orchangeability Extra Features ud z iant Interface M 7 Click the IVI COM Driver tab Select Agilent 34401 from the drop down list Note The VISA address that you entered earlier appears automatically in the Address field 8 Click OK The dialog closes and returns to the Instrument Properties dialog 9 Click OK The dialog closes and returns to the Instrument Manager Congratulations You can now access the IVI Driver in the Instrument Manager Note If the driver is correctly installed the text darkens on the IVI COM Driver button under Create I O Object in the list at the right Instrument Manager 21x Instrument List My Configuration C Documents and SettingsinbergquiLocal Setting GPIBO myDmm GPIBO 23 INSTR Auto Discovery Configure Drivers Settings Instrument Properties Create an Instance of the Driver 1 Click IVI COM Driver under Create I O Object at the right An outline of the object appears 2 Move the object onto your workspace Using IVI with Agilent VEE Pro 96 5 6 Double click Double Click to Add Operation in the To From myDMM object The Select an Operation dialog box
37. appears Select Createlnstance to create an instance of the Agilent 34401 driver Note At the bottom of the dialog box the code for the operation appears along with an explanation of its function Select an Operation from Agilent34401Class Createlnstance Initialize Close aeS AC eS ACCurrent amp amp ACVoltage w eS Advanced w eS Calibration eS DCCurrent amp amp DCVoltage wes DCVoltageRatio amp amp Display eS DriverOperation ES Frequency amp amp Function ES Identity ES Initialized Createlnstance Agilent Agilent34401 Interop Agilent Agilent34401 Interop Agilent34401 Class Create the IVI COM driver Click OK The Edit Createlnstance dialog box appears Click OK Initialize the Instrument Chapter 10 1 2 Double click to add another operation The Select an Operation dialog box appears Select Initialize to initialize the simulated Agilent 34401 Click OK The Edit Initialize dialog box appears 3 4 In the Edit Initialize dialog box GPIBO 23 INSTR has already been entered in the ResourceName field Enter or select the following e False in the IdQuery field True in the Reset field e simulatez true in the OptionString field Click OK Configure the Instrument 1 Double click to add another operation The Select an Operation dialog box appears 2 Expand the treenode DCVoltage and select Configure Click OK The Edit Configure dialog box appears
38. applications quickly by writing code to accompany on screen objects such as buttons windows and dialog boxes This chapter focuses on VB 6 0 which is not the most current version If you are new to VB we recommend you refer to Chapter 3 Using IVI with C and Visual Basic NET Example Requirements Visual Basic 6 0 Microsoft Visual Studio 6 0 Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it You can also refer to Chapter 1 Download and Install IVI Drivers for instructions This example uses an IVI COM driver IVI COM is the preferred driver for Visual Basic 6 0 but IVI C is also supported via the inclusion of bas files Create a New Project and Reference the Driver To use an IVI Driver in a Visual Basic program you must first create a project and add a reference to the driver 1 Launch Visual Basic and create a new project using Standard EXE project Note This creates a Windows Application program eccccc co 5 86 Add a Button Chapter 9 2 3 4 From the Start Menu select Project and click References The References dialog appears Select the IVI Agilent34401 1 1 Type Library from the drop down list Place a check in the box next to this driver Note If you have
39. ar argv if InitCVIRTE 0 argv 0 0 return 1 out of memory hp34401a InitWithOptions GPIBO 23 INSTR VI FALSE VI TRUE Simulate 1 amp session hp34401a ConfigureMeasurement session HP34401A VAL DC VOLTS 1 5 0 001 hp34401a ConfigureTrigger session HP34401A VAL IMMEDIATE 0 01 hp34401a Read session 1000 amp reading printf f reading hp34401a close session return 0 Note To display the reading add a printf function Before the Close function type printf f reading Note Including error checking in your programs is good practice Use the CheckErr macro provided in the ivi h file to handle errors See the example included with the hp34401 downloaded driver for error handling demonstration code Further Information Learn more about LabWindows CVI at http www ni com lwcvi The mark LabWindows is used under a license from Microsoft Corporation Using IVI with LabWindowsTM CVITM 55 56 Chapter 5 Chapter 6 Using IVI with MATLAB The Development Environment MATLAB from The MathWorks is an interactive software environment for data acquisition and analysis waveform generation algorithm creation and test system development MATLAB also provides a technical computing language that is designed to help you solve technical challenges faster than with traditional software environments MATLAB supports IVI instrument drivers using the Instrument Control Toolbox The
40. ary Our examples use the Virtual Instrument Software Architecture VISA a widely used standard library for communicating with instruments from a personal computer Shared Components To make it easier for you to combine drivers and other software from various vendors the IVI Foundation members have cooperated to provide common software components called IVI Shared Components These components provide Services to drivers and driver clients that need to be common to all drivers For instance the IVI Configuration Server enables administration of system wide configuration Important You must install the IVI Shared Components before an IVI driver can be installed The IVI Shared Components can be downloaded from vendors web sites as well as from the IVI Foundation Web site To download and install shared components from the IVI Foundation Web site 1 Go to the IVI Foundation Web site at http Avww ivifoundation org 2 Locate Shared Components 3 Choose the IVI Shared Components msi file for the Microsoft Windows Installer package or the IVI Shared Components exe for the executable installer Download and Install IVI Drivers After you ve installed Shared Components you re ready to download and install an IVI driver For most ADEs the steps to download and install an IVI driver are identical For the few that require a different process the relevant chapter in IVI Getting Started Guide provides the information you need IVI Drivers a
41. ate caching IVI drivers keep track of an instrument s status so that I O is only performed when necessary preventing redundant configuration commands from being sent This can significantly improve test system performance Interchangeability IVI drivers enable exchange of instruments with minimal code changes reducing the time and effort needed to integrate measurement devices into new or existing systems The IVI class specifications provide syntactic interchangeability but may not provide behavioral interchangeability In other words the program may run on two different instruments but the results may not be the same due to differences in the way the instrument itself functions Flavors of IVI Drivers To support all popular programming languages and development environments IVI drivers provide either an IVI C or an IVI COM Component Object Model API Driver developers may provide either or both interfaces as well as wrapper interfaces optimized for specific development environments Although the functionality is the same IVI C drivers are optimized for use in ANSI C development environments IVI COM drivers are optimized for environments that support the Component Object Model COM IVI C drivers extend the VXIplug amp play driver specification and their usage is similar IVI COM drivers provide easy access to instrument functionality through methods and properties All IVI drivers communicate to the instrument through an I O Libr
42. ation from Read VI to Close VI Note LabVIEW compiles while developing which lets you check the program execution at any time Add Error Checking 1 Return to the main functions palette From the Dialog amp User Interface subpalette select Simple Error Handler VI and place it on the Block Diagram 2 Connect the error information from Close VI to Simple Error Handler VI Run the Application Your final VI Block Diagram should contain the elements shown below To run your VI 1 Switch to the VI s Front Panel and click on the Run arrow to run the application 2 The Reading indicator should display a simulated reading from the instrument IVI Demo IVI C vi Block Diagram BEE File Edit View Project Operate Tools Window Help 5 8 amp m El bole af 13pt Application Font w 2 32 e Resolution 0 001 Measurement Function DC volts Simulate 1 Timeout 1000 4 GPIBO 23 INSTR v IdQuery 1 Reset uon Gs x Range TriggerDelay 0 01 TM Using IVI with LabVIEW ecc cc 06 gt Setting a Property in an IVI C Driver Properties such as Trigger Delay can also be set and read with a property node This is important in cases where a configuration function is not provided by the driver For example we can replace steps 4 and 5 of the Configure the Instrument section with 1 From the Functions palette select Application Control and drop a Property N
43. ay be ke2000 read while another may be hp34401 get or something even farther afield Without consistency across instruments manufactured by different vendors many programmers still spent a lot of time learning each individual driver To carry VXlplug amp play drivers a step or two further in 1998 a group of end users instrument vendors software vendors system suppliers and system integrators joined together to form a consortium called the Interchangeable Virtual Instruments IVI Foundation If you look at the membership it s clear that many of the foundation members are competitors But all agreed on the need to promote specifications for programming test instruments that provide better performance reduce the cost of program development and maintenance and simplify interchangeability For example for any IVI driver developed for a DMM the measurement command is lviDbmmMeasurement Read regardless of the vendor Once you learn how to program the commands specified by IVI for the instrument class you can use any vendor s instrument and not need to relearn the commands Also commands that are common to all drivers such as nitialize and Close are identical regardless of the type of instrument This commonality lets you spend less time hunting around the help files and programming an instrument leaving more time to get your job done That was the motivation behind the development of IVI drivers The IVI specifications enable drivers wi
44. c File 1 0 Boolean zz ER gt o EA String Comparison Timing m gj a k Dialog amp User Waveform Application C G eee Je Qo Ci Bdy Synchronization Graphics amp So Report Gener Measurement I O Instrument I O Vision and Motion Mathematics Signal Processing Data Communication Connectivity Control Design amp Simulation SignalExpress Express Addons Favorites User Libraries Select a VI LI L L L a L L 45 Connectivity ActiveX L n a e G 3 Activex m Automation Open J Libraries amp Ex Source Control Port 1 0 oJ E m pM B om ca Eb j CH Automation Close Refere To Variant Variant To Data Multisim Tools T pz ner ees gt tho B E Den Property Node Invoke Node Register Eve Unregister Fo NET Input Device Activex B Static VI Refe 6 Right click on the Automation Refnum terminal select Select ActiveX Class and then Browse TM Using IVI with LabVIEW eeccccc A 44 7 From the Type Library drop down select the IVI Agilent 34401A Agilent Technologies 1 1 Type Library Version 1 1 and then select the lAgilent34401 object Click OK Note If the IVI COM driver you want to use is not listed download and install the driver and close and restart LabVIEW The driver should now appear in the type library browser
45. crosoft and Visual Studio are registered trademarks of Microsoft Corporation in the United States and or other countries Chapter 2 Chapter 3 Using IVI with Visual C and Visual Basic NET The Environment C and Visual Basic are object oriented programming languages developed by Microsoft They enable programmers to quickly build a wide range of applications for the Microsoft NET platform This chapter provides detailed instructions in C as well as the code for Visual Basic If you are looking for an example using Visual Basic 6 0 refer to Chapter 9 Note One of the key advantages of using C and Visual Basic in the Microsoff Visual Studio Integrated Development Environment is IntelliSense InstelliSense is a form of autocompletion for variable names and functions and a convenient way to access parameter lists and ensure correct syntax The feature also enhances software development by reducing the amount of keyboard input required Example Requirements Visual C Microsoft Visual Studio 2005 Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it You can also refer to Chapter 1 Download and Install IVI Drivers for instructions This example uses an IVI COM driver IVI COM is the preferred
46. ct Insert Construct and click Main 2 Find the hp34401a instrument driver in the instrument driver tree Select Initialize with Options from the library tree The Initialize with Options function panel opens 3 Enter values for Resource Name ID Query Reset Device and Option String e GPIBO 23 INSTR in the Resource Name field e No for ID Query control e Yes for Reset Device control Simulatez1 in the Options field Note The RangeCheck QuerylnstrStatus and Cache options appear automatically The options are enabled by default Sil c MVI DemoWVVI Demo cws HP 344014 Digital Multimeter Initialize With Options Sie Eck View Code Quid Run Instrument Ubrary Took Window Options Help HESS hea so Rkhasi s amp IVI Demo al gt Source Fiet Copynght 1998 National Iristsuments Copaon AR Rights Reserved Ed M Demo c Instrument File 7m wakak feros inane Fd Reset Derice j GPIB0 23 INSTR Yes Fe No LIS a0 Libres O Instruments Option Sting o HP 344014 Digtal b DS n dl inf wirhOptens Corgon 4 Measurement Utity close Sinulate 1 Rangecheck 1 QueryInstrStatus 1 Cache 1 hp34401a_InatWathOptions GPIBO 23 INSTR VI FALSE VI TRUE 4 Sinulate 1 RangeCheck 1 QueryInstrStatus 1 C P Fa 4 Select the Instrument Handle parameter From the Code Menu click Declare Variable to set the Instrument Handle parameter 5 Enter session in the Variable Name field 6 Check the boxes titl
47. d and registered on your System This read only component is commonly provided by the instrument vendor and contains the commands and functions necessary to communicate with the instrument You can use the software module entry data to locate the component on your system and determine what instrument models and class interfaces called Published APIs in the configuration server are supported by the component HardwareAsset A HardwareAsset describes a specific physical device in your system with which you communicate such as an oscilloscope or power supply The HardwareAsset includes a resource descriptor a string that specifies the I O interface and address of a hardware asset such as GPIB 23 INSTR DriverSession DriverSession provides the information needed to use a driver in a particular context It makes the association between a SoftwareModule and a HardwareAsset It defines a set of properties for use by IVI instrument driver software modules such as initial configurable settings for attributes virtual name mappings and simulation settings You can configure a DriverSession for each instrument for each of its possible I O resource descriptors and for each program that uses it LogicalName A LogicalName is a configurable pointer to a particular DriverSession Application programs use logical names to avoid direct references to software modules and hardware assets In a typical setup the application communicates with an instru
48. e End Sub Further Information Learn more about Visual Basic at http msdn microsoft com library default asp url library en us dnanchor html vb6anchor asp Microsoft and Visual Studio are registered trademarks of Microsoft Corporation in the United States and or other countries Using IVI with Visual Basic 6 0 92 Chapter 9 Chapter 10 Using IVI with Agilent VEE Pro The Development Environment Agilent Visual Engineering Environment Pro is a graphical programming environment designed to help you quickly create and automate measurements and tests VEE Pro lets you program by creating an intuitive block diagram You select and edit objects from pull down menus and connect them to specify the program flow VEE Pro also includes Instrument Manager which facilitates control and management of your devices Let s see how VEE Pro works with IVI Example Requirements Agilent VEE Pro 8 0 Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it You can also refer to Chapter 1 Download and Install IVI Drivers for instructions This example uses the IVI COM driver VEE Pro does not support the use of IVI C drivers through the Instrument Manager Launch the Instrument Manager and Select the Driver I
49. e eee ee 49 Create a New Project and Add Instrument Driver Files 49 Initialize the Instrument 0 00 00 e eee eee 50 Configure the Instrument 0 06 cece eee eee eee 52 Set the Reading Timeout 00 0 cc eee 53 Display the Reading 54 Close the Session 0 ccc cece cette 54 Contents Contents Chapter 6 Chapter 7 Chapter 8 Further Informati n sasise ai a iaa aa ai a iaa aia aii a aaia RR 55 Using IVI with MATLABB Liieeiesu horreur nmn 57 The Development Environment lllssss esses eese 57 Example Requirements 00 0 c eee eee eene 57 Download and Install the Driver 00000 cece 57 Configure the IVI Driver llis 58 Generate an Instrument Wrapper 0 000e eee eee eee 61 Configure and Control the Instrument 0 000 eee eee 61 Create an Instance of the Instrument 0 05 61 Connect to the Instrument 0 00000 ee eee eee 61 Configure the Instrument 0 0 00 cece eee eee 61 Set the Trigger Delay 0 000 cece eee 62 Set Reading Timeout 000 cece eee 62 Display Reading 0 cee eee 62 Disconnect from the Instrument 0 000 e eee eee 62 Remove the Driver from Memory 0 0e eee eaee 62 Further Information 00000 ccc eee eee eee eee 63 Using IVI with Measure Foundry 00ceeeee eee eees 65 The Environment
50. eclarations you added in the previous section checkErr hp34401a InitWithOptions GPIB 23 INSTR VI FALSE VI TRUE Simulate 1 amp session This initializes the instrument with the following parameters GPIBO 23 INSTR as the Resource Name instrument at GPIB address 23 e VI FALSE Does not perform an ID Query e V TRUE Resets the device Using IVI with Visual C eoeecee N oa 26 Simulate 1 in the Options parameter sets the driver to simulation mode amp session assigns the Instrument Handle to the variable session defined above Configure the Instrument 1 Tosetthe range to 1 5 volts and resolution to 0 001 millivolts type checkErr hp34401a ConfigureMeasurement session HP34401A VAL DC VOLTS 1 5 0 001 Set the Trigger and Trigger Delay 1 Tosetthe trigger source to immediate and the trigger delay to 0 01 seconds type checkErr hp34401a ConfigureTrigger session HP34401A VAL IMMEDIATE 0 01 Set the cua Timeout Display the Reading To take a reading from the instrument and to set the reading timeout to 1 second 1000 ms type checkErr hp34401a Read session 1000 amp reading Note The Read function takes a reading from the instrument and assigns the result to the variable reading defined above 2 To display the reading use a printf statement Type printf Reading f reading Close the Session To close out the instance of the driver
51. ed Execute declaration in Interactive Window and Add declaration to top of target file c Click OK Note To test the function with the specified parameter values select Code and click Run Function Panel or click the run button in the toolbar to operate the function panel interactively 7 From the Code Menu click Insert Function Call to insert the function and values into your program Close the function panel The hp34401a InitWithOptions function appears in your program Using IVI with LabWindowsTM CVITM 51 52 Gl c MVI DemoMVI Demo cws IV Demo c m m PM nn poem Uy De ane QUNM Um BESO eB Adie sk nU PO MI Demo All includ censi ohy 6 Source Files finclude apana h EID z ide cvirte h _ ies etatio ViResl64 reading m x wn 4 static ViSession session int main int argc char wargv C Liveries al if InitCVIRTE 0 argv 0 0 Inet return lt 1 out of menory yurmenis T HP 344014 Digital h hp34401a InitVithOptions GPIBO 23 INSTR VI FALSE ER r VI TRUE S S Sinulates1 RangeCheck 1 QueryI ES Inf w tnO tions amp session Corgon Measurement Uti 4 return 0 Configure the Instrument Chapter 5 1 From the library tree select Configuration and click ConfigureMeasurement The ConfigureMeasurement function panel opens 2 Set the function to DC Voltage range to 1 5 volts resolution to 1 millivolt and instrument handle to session Select
52. ee 22 Using IVI C in Visual C 000 cece ee 22 Contents Contents Chapter 3 Chapter 4 Create a New Project and Import the Driver Type Libraries 22 Declare Variables 00 ccc eee ees 24 Define Error Checking 0 0 0c cece eee eee eee 25 Initialize the Instrument 0 00 eee 25 Configure the Instrument 0 00 0000 ccc cee eee 26 Set the Trigger and Trigger Delay 0 000 cece eee eee 26 Set the Reading Timeout Display the Reading 26 Close the Session 00 c eee t eee eee 26 Build and Run the Application 0 00 c eee eee eee 27 Further Information llle 28 Using IVI with Visual C and Visual Basic NET 29 The Environment 20 02 cece nh 29 Example Requirements 0 0 cece eee eens 29 Download and Install the Driver 0 00 cece eee ee 29 Create a New Project and Reference the Driver 30 Create an Instance of the Driver llli esee 31 Initialize the Instrument lseleleeen BB 32 Configure the Instrument 33 Set the Trigger Delay 0 0 0 cee eens 33 Set the Reading Timeout Display the Reading 33 Close the Session 0 000 cece tte tees 33 Build and Run the Application 2 0 cee eee eee eee 34 TAPS isco eode pe irr ate brem shane de ep iho iS tage ton d eai a rs 34 Further Information llle 35
53. eed to determine the VISA address string for your instrument and the ADE does not provide it automatically use an IO application such as National Instruments Measurement and Automation Explorer MAX or Agilent Connection Expert e Reference the driver or load driver files For the examples in this guide the driver is the Agilent 34401A IVI COM Specific Driver Version 1 1 0 11 March 2006 from Agilent Technologies or the Agilent 34401A IVI C Specific driver Version 4 1 October 2006 from National Instruments Create an instance of the driver in ADEs that use COM For the examples in this guide the driver is the Agilent 34401A IVI COM or HP 34401 IVI C Write the program e initialize the instrument Initialize is required when using any IVI driver Initialize establishes a communication link with the instrument and must be called before the program can do anything with the instrument We set reset to true ID query to false and simulate to true Setting reset to true tells the driver to initially reset the instrument Setting the ID query to false prevents the driver from verifying that the connected instrument is the one the driver was written for Finally setting simulate to true tells the driver that it should not attempt to connect to a physical instrument but use a simulation of the instrument e Configure the instrument We set a range of 1 5 volts and a resolution of 0 001 volts 1 millivolt e Access a
54. es the instrument The instrument will be initialized with the properties you specified using the Test amp Measurement Tool Type connect myDmm Configure the Instrument To set a range of 1 5 volts and resolution of 0 001 volts type myDmm Range 1 5 myDmm Resolution 0 001 Using IVI with MATLAB 61 62 Chapter 6 Set the Trigger Delay To set the trigger delay to 0 01 seconds type myDmm Trigger Delay 0 01 Set Reading Timeout To take a reading with a timeout of 1 second type myDmm Timeout 0 01 Display Reading To display the reading type data invoke myDmm Measurement Read 1000 Disconnect from the Instrument Similar to the Close command in most ADEs the Disconnect command in MATLAB closes the instrument To disconnect type disconnect myDmm Remove the Driver from Memory To remove any reference to the driver from memory type delete myDmm Your final application should contain the code below gt gt myDmm icdevice dmm gt gt connect myDmm gt gt myDmm Range 1 5 gt gt myDmm Resolution 0 001 gt gt myDmm Trigger Delay 0 01 gt gt myDmm Timeout 0 01 gt gt data invoke myDmm Measurement Read 1000 data 0 5116 gt gt disconnect myDmm gt gt delete myDmm Further Information To learn more about using MATLAB with IVI instrument drivers visit http www mathworks com ivi MATLAB is a registered
55. esistance eS Status System Sub Initialize Resoucenare AS String IdQuery As Boolean Reset As Boolean OptionString As String Member of Agilent34401Lib Agilent34401 Opens the I O session to the instrument Driver methods and properties that access the instrument are only accessible after Initialize is called Initialize optionally performs a Reset and queries the instrument to validate the instrument model Configure the Instrument Set the function to DC Voltage range to 1 5 volts and resolution to 1 millivolt 1 Type dmm Function Agilent34401FunctionDCVolts 2 Type dmm DCVoltage Configure 1 5 0 001 3 Select Configure from the drop down list and press the space bar Note The Object Browser shows the parameters and syntax for Configure in the box at bottom along with a short description 4 Typei 5 0 001 Chapter 9 Set the Trigger Delay Set the trigger delay to 0 01 seconds Type dmm Trigger Delay 0 01 Display the Reading Set the reading timeout to 1 second and display the reading 1 Return to the form view and click the Label Button in the Toolbox to create a label Drag it to the form and drop it Change the Name to IbIResult in the Properties list at right Remove the text under Caption a Fk WN In the code after the trigger delay command type lblResult Caption dmm Measurement Read 1000 Close the Session Type dmm Close Your final program should contain the code below
56. f you have correctly installed the IVI driver VEE Pro s Instrument Manager will automatically find it for you 1 Launch VEE Pro 2 From the Main Menu select I O and click Instrument Manager Note If you were connected to a live instrument you would click the Find Instruments button at the right in this screen and then skip to the next section eccccc ae oo 94 Chapter 10 3 Click Add under instrument in the list at the right to add a simulated instrument The Instrument Properties dialog box appears 4 Inthe Instrument Properties dialog box enter or select the following e myDMM in the Name field GPIB in the Interface field e OQ in the Board Number field e GPIBO0 23 INSTR in the VISA Address field Instrument Manager Instrument List Auto Discovery 9 My Configuration C Documents and Settingsinbergqu Local Setting Find Instruments instrument Properties Configure Drivers Settings Name myOmm Settings Interface Instrument Board Number VISA Alias VISA Address 5pigg 23 INSTR e g GPIBO 12 INSTR Advanced OK Cancel Help 5 Click Advanced The Advanced Instrument Properties dialog box appears 6 Click the IVI COM Driver tab Select Agilent 34401 from the drop down list Note The VISA adaress that you entered earlier appears automaticaly in the Address field Advanced Instrument Properties General Direct VO Plug amp play Driver IVI COM Driver P
57. it You can also refer to Chapter 1 Download and Install IVI Drivers for instructions This example uses an IVI C driver IVI C is the preferred driver for LabWindows CVI Create a New Project and Add Instrument Driver Files 1 Launch LabWindows CVI 2 Select File select New and click Project 3 Tocreate a new C source file select New and click Source c Save the file 4 Select Edit and click on Add Files to Project to add the C source file to your project 5 Select Edit and click on Add Files To Project to add one of the following instrument driver files to your project hp34401a fp hp34401a c or hp344014a lib eccccc A e 50 Cil c VI DemoWVI Demo cws Workspace Project Source c Include h Object obj Library lib User Interface uir 6 FD Include File in Build Ctrl E Enable O Option Replace File in Project Remove File Del Ee Find ess b C3 Libraries A E gt Instruments ff HP 344014 Dig Note Any of the three files listed above will work Adding one of the HP 34401A instrument driver files loads that instrument driver View the available functions in the library tree in the workspace window 6 Add the following line to your program to include the instrument driver header file include hp34401a h Initialize the Instrument Chapter 5 1 From the Edit menu sele
58. lled only once when the Paws project is unloaded from the run time system From the Main Menu select Options and click on CEM The WCEM dialog appears Select the Files tab and enter C Program Files IVI Include in the Include Path field Click Apply Note The path includes the Visacom i c file from the DMM h header From the Main Menu select Build and click on Rebuild All The Output area appears with a message that indicates the project was successfully built Note Most of the IVI COM driver methods return HRESULT value which is used in this example across the entire driver implementation for error handling Error handling code is recommended as you develop a PAWS application In our example the error handling code begins with if FAILED hr and ends with the after the Display line for most of the methods Prepare the Run Time System Environment Chapter 8 1 In the Project Workspace area double click on the Busconfi The DMM name in a Busconfi file corresponds to the name defined in the dmm ddb file following the begin dev statement Set the Listen Address MLA and Talk Address MTA to the device address of 23 The Bus number must correspond to the Channel number The Busconfi code should appear as below IEEE 488 Bus Configuration File Channel 1 DMM BUS 1 MLA 23 MTA 23 Load and Run the Project 1 From the Main Menu select Build and click on Execute Wrts Note The message below may appea
59. lose Some capabilities are required for all drivers but others are optional Base class capabilities capabilities identified by an IVI Foundation working group as common among the majority of instruments in a class In the DMM class for example base capabilities include performing a DC voltage or current measurement Class extension capabilities capabilities identified by an IVI Foundation working group as less common but still supported by multiple instruments within a class In the DMM class for example class extension capabilities include temperature measurement Instrument specific or vendor specific capabilities capabilities not standardized by IVI and unique to a manufacturer s specific instrument In the DMM class for example this might be a measurement that uses a thermocouple to sense the temperature Application Program IVI C Class Interface IVI COM Specific Driver IVI C Class Compliant Specific Driver 1 0 Library Instrumentation Hardware Now that we ve defined the capabilities we can look at each driver in terms of those it supports Custom Specific Driver This driver supports only IVI inherent capabilities and instrument specific capabilities but not base class or class extension capabilities This lets instrument manufacturers 1 innovate and provide specialized features and 2 supply IVI drivers for instruments for which no class specification exists such as network ana
60. lowing code in the DMM cpp file directly below include key h code include DMM h CComPtr IAgilent34401 driver CComPtr IAgilent34401DCVoltage pDMMDCVolt CComPtr lt IAgilent34401Trigger gt pDMMTrig CComPtr IAgilent34401Measurement pDMMData HRESULT hr To create the driver object and open an I O session to the instrument with the Initialize method select the ctrl cpp file from the PAWS Project window Note To determine the syntax for the commands you want to use in your program consult the driver help file 5 In the doOpen interface function insert the following code below the line Please insert your CEM driver code here if if driver CoCreateInstance CLSID_Agilent34401 FAILED hr Display 033 30 41m Bad return from CoCreateInstance method 033 m n driver gt Initialize CComBSTR GPIBO 23 INSTR VARIANT_FALSE VARIANT_TRUE CComBSTR Simulate TRUE FAILED hr Displ metho ay 033 30 41lm Bad return from Initialize d 033 m n Note doOpen is called for the first time when the run time system loads the PAWS project If you intend to use non ATLAS modules in your ATLAS code subsequent calls to doOpen will be made and you will need to execute the code above only once To set the function for DC Voltage the range to 1 5 volts and the resolution to 1 millivolt select the DMM cpp file from the PAWS Project
61. ly include their own I O that does not require VISA Shared Components IVI Foundation members have cooperated to provide common software components called IVI Shared Components that ensure compatibility among drivers from various manufacturers These components provide services to drivers and driver clients that need to be common to all drivers IVI Configuration Server This component is the run time module responsible for providing configuration data to IVI drivers The Configuration Server specifically provides system initialization and configuration information COM Session Factory This component can dynamically load an IVI COM software module without requiring the application program to identify the IVI software module when it is compiled This allows the test program source code to have all references to a specific instrument removed This capability is provided in IVI C using an IVI C Class driver Interchangeability Chapter 11 One aspect of the IVI standard is instrument interchangeability which allows you to write and compile your program for an instrument from one manufacturer and then swap it out for the same type of instrument from another manufacturer After making changes to a configuration file on your computer to identify the new instrument and driver and the hardware address if that changes you can run your program without modifying or recompiling it That s in an ideal world of course The minimum necessary
62. lyzers and Bluetooth testers Class Compliant Specific Driver This driver must support inherent and base class capabilities These drivers may also support class extensions and instrument specific capabilities For IVI C and IVI COM drivers a Class Compliant Specific Driver enables interchangeability through generic instrument Application Programming Interfaces APIs that can be used with a multitude of instruments See more about APIs below Class Driver This driver is used for IVI C only A Class Driver also supports inherent base class and all class extension capabilities A Class Driver enables instrument interchangeability when using IVI C Class Compliant Specific Drivers For IVI COM drivers the IVI inherent capabilities custom capabilities and the class capabilities may be provided in a single driver All IVI COM drivers include the inherent capabilities If an IVI COM driver only has custom and inherent Advanced Topics 103 capabilities it is called an IVI COM custom driver If the driver includes the class capabilities it is called an IVI COM Class Compliant driver IVI COM Class Compliant drivers may or may not include custom capabilities Instrument I O All IVI drivers communicate to the instrument hardware through an I O Library The VISA library is typically used because it provides uniform access to GPIB RS 232 USB TMC and LAN instrument Drivers that communicate with insruments that only use RS 232 or LAN occasional
63. ment via a logical name If the application needs to communicate with a different instrument for example the same kind of scope at a different location only the logical name within the IVI Configuration Store needs to be updated to point to the new driver session You don t need to rewrite any code in the application because it uses the same logical name The illustration below shows how the IVI Configuration Store enables interchangeability The application is developed and makes calls via the logical name In the illustration this is shown as DMM The actual DMM is from Vendor X at address GPIB1 21 INSTR and uses the Vendor X DMM IVI COM driver In the Configuration Store the logical name DMM is associated with a Driver Session that is configured to the specific information of the Vendor X DMM Advanced Topics 4107 Chapter 11 NENNEN OO ee x Vendor X DMM GPB T 21 4NSTR Vendor X DMM NI COM Driver IVI Configuration Store Logical Name DMM Dnver Session Vendor X DMM Hardware Asset GPIB1 21 INSTR Software Module Vendor X DMM IVI COM Driver Dnver Session Vendor Y DMM Hardware Asset GPIBO 23 INSTR Software Module Vendor Y DMM IVI COM Oriver In the illustration below we replace the Vendor X DMM with a Vendor Y DMM All we need to do is change the LogicalName so that it points to a different DriverSession lnthis example change the LogicalName so that it point to the Vendor Y DriverSes
64. n instrument property We set the trigger delay to 0 01 seconds e Set the reading timeout We set the reading timeout to 1000 milliseconds 1 second e Take a reading e Close the instrument This step is required when using any IVI driver unless the ADE explicitly does not require it We close the session to free resources Important Close may be the most commonly missed step when using an IVI driver Failing to do this could mean that system resources are not freed up and your program may behave unexpectedly on subsequent executions Check the driver for any errors Display the reading Note Examples that use a console application do not show the display Now that you understand the logic behind IVI drivers let s see how to get started Introduction 16 Chapter 1 The Environment Chapter 2 Using IVI with Visual C Microsoft Visual C is a software development environment for the C programming language and is available as part of Microsoft Visual Studio Visual C allows you to create debug and execute conventional applications as well as applications that target the NET Framework Example Requirements Visual C Microsoft Visual Studio 2005 IVI COM Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies or IVI C Agilent 34401A IVI C Version 4 1 October 2006 from National Instruments Agilent IO Libraries Suite 14 2 Download and Install the Drive
65. n the Windows NT 2000 XP Platform environment PAWS supports a full range of the most commonly used ATLAS Language subsets A PAWS Toolkit can modify the ATLAS Language subset to meet a particular Automatic Test Equipment ATE configuration Its output can be executed on the associated Debugging PAWS RTS run time system or can be translated to run on your unique run time system Creation of a PAWS project typically consists of three main steps Prepare the PAWS environment Connect to the instrument driver Prepare the run time system environment and run the project Example Requirements TYX PAWS Studio 1 34 6 Microsoft Visual Studio Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it You can also refer to Chapter 1 Download and Install IVI Drivers for instructions This example uses an IVI COM driver PAWS supports both IVI COM and IVI C drivers Note If you do not install the appropriate instrument driver the project will not build because the referenced files are not included in the program If you need to LLL J AL wo download and install a driver you do not need to exit PAWS Studio Install the driver and continue with your program Prepare the PAWS Environment To use an IVI Driver in PA
66. nd Methods double click the Measurement property and select the Read method Click Create and drag the Invoke Node to the Block Diagram 2 Set the value for Timeout to 1 second 1000 ms by entering 1000 in the MaxTimeMilliseconds field 3 Connect the automation refnum and error terminals from Trigger Delay Property Node to Measurement Read Invoke Node Display the Reading Create an indicator for Measurement Read from the Invoke Node terminal Close the Driver and Automation Sessions 1 Return to the Class Browser and under Properties and Methods double click the Close method Click Create and drag the Invoke Node to the Block Diagram 2 Close the Class Browser From the ActiveX subpalette select Close Reference and place on the Block Diagram 3 Connect the automation refnum and error terminals from Measurement Read Invoke Node to Close Invoke Node and then to Close Reference function Add Error Checking 1 Return to the main functions palette From the Dialog amp User Interface subpalette select Simple Error Handler VI and place it on the Block Diagram 2 Connect the error information from Close Reference function to Simple Error Handler VI 46 Chapter 4 Run the Application Your final VI Block Diagram should contain the elements shown below To run your VI 1 Switch to the VI s Front Panel and click on the Run arrow to run the application 2 The Reading indicator should display a simulated reading from the instrument I
67. ne Using IVI with Measure Foundry amp Data Sink The property pages contain all the information necessary to display the output 1 In the Foundry window select Display Components Drag and drop the Single Value Label onto the form 2 Double click the Single Value Label The Properties of Single Value Label dialog appears 3 Scroll the list of Data sources and click Form ivi2 IVI Dmm 4 Check the box by DCV in the Channels field e Data sources Form ivi2 IVl Dmm e Channels Moc Compile and Run The final program contains the IVC Dmm LXI component data source Start Stop button control source and Single Value Label data sink From the Start Menu click Compile and Run to check that your program runs Close Session To close the session and release the driver either exit the program or program a Control Button to set the Disconnect property to true in the IVI DMM component Further Information Learn more about the Measure Foundry at http www measurefoundry com 70 Chapter 7 DT Measure Foundry is a registered trademark of Data Translation States and or other countries in the United Using IVI with Measure Foundry 72 Chapter 7 Chapter 8 Using IVI with PAWS The Environment PAWS Developer s Studio gives you the capability to edit compile modify debug document execute and simulate the test procedures developed in Abbreviated Test Language for All Systems ATLAS i
68. num FP IIviTrace Enabled E AY Aglent34401Class Ha Agllent34401dBmRefResistanc 5 399 Agilent34401ErrorCodesEnum Initiate amp aP Agilent34401FunctionEnum F InputTerminal amp aP Agilent34401InputTerminalEn A InputVokageM amp aP Agilent34401MathFunctionEnu Z InputVokageMin amp aP Agilent34401MeasCompleteDe 59 Ins Bind EaP Agilent34401ResolutionEnum AP InstrumentFirmwareRevis E amp aif Agilent34401SampleTriggerEm R InstrumentManufacturer S aP Agilent344015tatusRegisterEn 5 inst tModel amp aP Agilent34401 StatusSubRegiste OF InterchangeCheck amp aP Agilent34401TriggerSlopeEnun Invalidateallattributes amp aP Agilent34401 TriggerSourceEnt 510 IAgilent34401 10 dio IAglent34401AC f IoResourceDescriptor amp o IAgilent34401ACCurrent Vir HDD ERR ties x gt o IAglent34401ACVokage ic virtual void vea string ResourceName amp IAgilent34401Calibration amp IAgilent34401DCCurrent REL Am Agilent34401Class amp IAgilent34401DCVoltage o IAgilent34401DCVoltageRatio s Initialize the Instrument Chapter 3 You can now write the main constructs for your program Create a variable to represent your instrument and set the Initialization parameters Type Agilent34401Class dmm new Agilent34401Class Type dmm Initialize GPIB 23 false true simulate true Note IntelliSense helps ensure you use correct syntax and values _ Program cs Start Page
69. o add the hp34401a instrument driver header file to your program type the following statement following the existing header file reference include hp34401a h 15 From the Main Menu select Build and click Build IVIDemo Declare Variables 1 You will need to declare some variables that will be used in your program Type the following lines after the inthe int main statement Chapter 2 ViSession session ViStatus error VI SUCCESS ViReal64 reading Define Error Che 1 cking Next define error checking for your program First you will define a macro to catch the errors It is better to define it once at the beginning of the program that to add the logic to each of your program statements After the include statements type the following lines ifndef checkErr define checkErr fCall N if error fCall error error 0 error VI_SUCCESS goto Error ls rror error endif Next you will type the following lines at the end of the program to handle any errors that occur Error if error VI_SUCCESS ViChar errStr 2048 hp34401a GetError session amp error 2048 errStr printf Error errStr Note Including error handling in your programs is good practice This code checks for errors in your program Initialize the Instrument 1 To initialize the instrument add the following Initialize with Options function right after the variable d
70. o namespace Note The import slatements access the driver type libraries used by the Agilent 34401 DMM The no namespace attribute allows the code to access the interfaces in the typelibraries from the global namespace To initialize the COM library type the following lines after the following the int statement HRESULT hr hr CoInitialize NULL IF FAILED hr exit 1 Note Including error handling in your programs is good practice This code checks for errors in your program To close the COM library before exiting type the following line at the end of your code right before the return line CoUninitialize Create an Instance of the Driver To create an instance of the driver type IIviDmmPtr dmm uuidof Agilent34401 Note This creates a smart pointer that provides easy access to the COM object You are now ready to write the program to control the simulated instrument Using IVI with Visual C 19 20 Initialize the Instrument You can now write the main constructs for your program Below the smart pointer statement type dmm slinitialize GPIB 23 false true simulate true Note As soon as you type Intellisense displays options and helps ensure you use correct syntax and values Configure the Instrument To set the range to 1 5 volts and resolution to 0 001 volts type dmm Configure IviDmmFunctionDCVolts 1 5 0 001 Eint tmain int argc TCHAR argv i HR
71. od 033 m n 10 11 12 13 hr pDMMData gt Initiate if FAILED hr Display 033 30 41lm Bad return from Initiate method 033 m n To set the reading timeout to 1 second select the DMM cpp file from the PAWS Project window Inthe DMM_Fetch interface function insert the following code below the line Please insert your CEM driver code here double Data 0 DATUM fdat hr pDMMData Fetch 1000 amp Data if FAILED hr Display 033 30 41lm Bad return from Fetch 1000 amp Data method 033 m n fdat FthDat DECDatVal fdat 0 Data FthCnt 1 Note The first argument in the Fetch method specifies how long to wait in the Fetch operation since it is possible that no data is available or the trigger event did not occur The second parameter contains the actual reading or a value indicating that an over range condition occurred To conserve resources you should close the driver session From the PAWS Project window select the ctrl cpp file In the doUnload interface function insert the following code below the line Please insert your CEM driver code here hr driver gt Close if FAILED hr Display 033 30 41lm Bad return from Close method 033 m n Using IVI with PAWS 81 82 Build the Project 1 2 driver Release pDMMData Release pDMMTrig Release pDMMDCVolt Release Note The function doUnload gets ca
72. ode on the Block Diagram 2 Connect the resource name and error information from Configure Measurement VI to the Property Node 3 Right click on the Property Node and select Change All to Write 4 Click on the Property field and select Trigger gt gt Trigger Delay IVI Demo IVI C wProperty vi Block Diagram BAR File Edit View Project Operate Tools Window Help ej smakke Resolution Measurement Function DC volts Simulate 1 Timeout 4 GPIBO 23 INSTR v my IdQuery Reset 5 E 8 at hp34401a a Trigger Delay TriggerDelay 0 01 Using IVI COM To use IVI COM drivers in LabVIEW you will use the ActiveX functions and the Class Browser that are built in to LabVIEW Create a Project and Access the Driver 1 Launch LabVIEW 42 Chapter 4 2 Fromthe File menu select New VI The Front Panel and Block Diagram appear 3 Right click in the Block Diagram The Functions palette appears 4 Selectthe Connectivity subpalette and then the ActiveX subpallete From this palette you can access ActiveX and COM objects including all IVI COM drivers 5 Select Automation Open from the palette and place it on the block diagram IVI Demo IVI COM vi Block Diagram File Edit View Project Operate Tools Window Help ec bae of 13pt Application Font ESES EM 9 m Q Search Lla elne 3 Functions Programming 4 L me gt Gal Structures Array Cluster amp Vari m a Gm E B Numeri
73. oid Main string args Agilent34401Class dmm new Agilent34401Class dmm Initialize GPIB 23 false true sim ulate true dmm DCVoltage Configure 1 5 0 001 dmm Trigger Delay 0 01 double reading reading dmm Measurement Read 1000 Console WriteLine The measurement is 0 reading Console ReadLine dmm Close Build and Run the Application Build your application and run it to verify it works properly From the Build menu click the name of your Console Application 2 From the Debug menu click Start Debugging The code for a Visual Basic console application in Visual Studio 2005 is almost identical to the C application Option Explicit On Imports Agilent Agilent34401 Interop Module Modulel Sub Main Dim dmm As New Agilent34401 dmm Initialize GPIB 23 False True simulate true dmm Function Agilent34401FunctionEnum Agilent34401FunctionDCVolts dmm DCVoltage Configure 1 5 0 001 dmm Trigger Delay 0 01 Dim reading As New Double reading dmm Measurement Read 1000 dmm Close Console WriteLine The reading is 0 reading Console ReadLine End Sub End Module The main differences include the following To use Visual Basic select Visual Basic in Project Types To enforce type checking insert a line at the start of the code Type Option Explicit On To call the DCVolts function you need to insert a
74. ot ate deat Sa he fale mtus bo cee Sota 109 IlviDrlVet cour term iaa Ohare Bae eae 109 TVAE Tra a t 110 jr 111 Editing the Configuration Store 0 0 0 0c cee 112 Future Development of IVI 2 112 IVI Drivers in Action 0 2 2 0 00000 cece eee 112 Chapter 1 Introduction Purpose Welcome to IVI Getting Started Guide This guide introduces key concepts about IVI drivers and shows you how to create a short program to perform a measurement The guide also provides a brief introduction to several advanced topics IVI Getting Started Guide is intended for individuals who write and run programs to control test and measurement instruments As you develop test programs you face decisions about how you communicate with the instruments Some of your choices include Direct I O VXIplug amp play drivers or IVI drivers If you are new to using IVI drivers or just want a quick refresher on how to get started IVI Getting Started Guide can help IVI Getting Started Guide shows you that IVI drivers can be straightforward easy to use tools IVI drivers provide a number of advantages that can save time and money during development while improving performance as well Whether you are starting a new program or making improvements to an existing one you should consider the use of IVI drivers to develop your test programs So consider this the hello instrument guide for IVI drivers If you recall the hello world program which o
75. r If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it Since Visual C supports both IVI COM and IVI C drivers this example is written two ways first to show how to use an IVI COM driver in Visual C and second to show how to use an IVI C driver in Visual C Note If you do not install the appropriate instrument driver the project will not build because the referenced files are not included in the program If you need to download and install a driver you do not need to exit Visual Studio Install the driver and continue with your program Using IVI COM in C The following sections show how to get started with an IVI COM driver in Visual C 18 Create a New Project and Import the Driver Type Libraries To use an IVI Driver in a Visual C program you must provide the path to the driver DLL H Environment E Performance Tools Projects and Solutions General Build and Run VB Defaults V C Directories VC Project Settings vCInstallDir PlatFormSDK lib Source Control Text Editor DevPartner Database Tools Debugging Device Tools HTML Designer Ge EC Er Ee Ee Er E Ee Rd Business Intelligence Designers Microsoft Office Keyboard Setting s A Platform Show directories for Win32 v Library files v Executable files Include files Reference files vCInstallbirlib eee Fie 2Vclnstalbe aint
76. r before invoking the Run Time system interface This message usually appears when you have changed the code without recompiling it Click Yes to let the project be rebuilt before execution If you make changes to the Busconfi file only you do not need to rebuild the project because it is used as a reference file at run time A 0x Some binary Files are not up to date Do you want to rebuild the affected files j Mo Cancel 2 Fromthe list at left select Run The program runs and returns a DC Voltage measurement Run Time System Production IEEE716 89 PAWS IVI COM DMM File View Run Control Window Help W Station Display Binary files atlas version 26660324 Date stamp Fri Jan 26 15 59 23 2007 Built In LEX Information CEM D Projects IUI IUI COM Demo IUT COH DHHNUCEH DLL CEM Module User Kernel Model 2 Version 26051129 3 9 3 ATLAS PROGRAM STARTS HERE DC VOLT MEASUREMENT 1 158622668864769E 66 UDC ATLAS PROGRAM ENDS HERE 3 From the Main Menu select File and click Exit to exit from the Run Time system Further Information Learn more about PAWS at http Awww tyx com pawsdeva html Using IVI with PAWS 83 84 Chapter 8 Chapter 9 Using IVI with Visual Basic 6 0 The Environment Visual Basic 6 0 is a programming environment derived from Basic and developed by Microsoft for the Windows operating system Software vendors and developers use VB to create
77. re available from your hardware or software vendor s web site or by linking to them from the IVI Foundation web site Introduction eoecoecee o To see the list of drivers registered with the IVI Foundation go to http www ivifoundation org Familiarizing Yourself with the Driver Examples Chapter 1 Although the examples in IVI Getting Started Guide use a DMM driver you will likely employ a variety of IVI drivers to develop test programs To jumpstart that task you ll want to familiarize yourself quickly with drivers you haven t used before Most ADEs provide a way to explore IVI drivers to learn their functionality In each chapter where applicable we add a note explaining how to view the available functions In addition browsing an IVI driver s help file often proves an excellent way to learn its functionality As we noted above each example chapter in IVI Getting Started Guide shows you how to use an IVI driver to write and run a program that performs a simple measurement on a simulated instrument and returns the result The examples demonstrate common steps using IVI drivers Where practical every example includes the steps listed below e Download and Install the IVI driver covered in the Download and Install IVI Drivers section above e Determine the VISA address string Examples in IVI Getting Started Guide use the simulate mode so we chose the address string GPIBO 23 INSTR often shown as GPIB 23 If you n
78. requirements for interchangeability include the following Drivers for both instruments must be of the same type IVI C or IVI COM Both drivers must implement the same instrument class For example both must conform to the requirements for IviDmm or IviScope e For IVI C your program must use a Class Driver which in turn instantiates the Class Compliant Specific Driver and calls class compliant functions in it Your program calls only those Class Extension functions supported by both drivers Your program never calls Instrument Specific functions The instruments must provide the same behavior at least with respect to the calling program Meeting these requirements is necessary to achieve 100 interchangeability However if your application does not meet all of these requirements in some cases you may be able to add additional code to your program to handle the differences between the instruments or drivers you are using and still achieve a certain degree of interchangeability The images below depict the functionality of the IVI Configuration Server and Configuration Store and COM Session Factory in their role of enabling interchangeability among IVI COM and IVI C drivers Interchangeability with IVI COM IVI Configuration Server IVI Configuration Advanced Topics 05 eocoqgene Interchangeability with IVI C Test System Setup User Test Program Application IVI C Class Driver
79. riginally appeared in Programming in C A Tutorial simply prints out hello world The hello instrument program performs a simple measurement on a simulated instrument and returns the result We think you ll find that far more useful Why Use an Instrument Driver To understand the benefits of IVI drivers we need to start by defining instrument drivers in general and describing why they are useful An instrument driver is a set of software routines that controls a programmable instrument Each routine corresponds to a programmatic operation such as configuring writing to reading from and triggering the instrument Instrument drivers simplify instrument control and reduce test program development time by eliminating the need to learn the programming protocol for each instrument Why IVI Chapter 1 Starting in the 1970s programmers used device dependent commands for computer control of instruments But lack of standardization meant even two digital multimeters from the same manufacturer might not use the same commands In the early 1990s a group of instrument manufacturers developed Standard Commands for Programmable Instrumentation SCPI This defined set of commands for controlling instruments uses ASCII characters providing some basic standardization and consistency to the commands used to control instruments For example when you want to measure a DC voltage the standard SCPI command is MEASURE VOLTAGE DC
80. ro at www agilent com find vee Using IVI with Agilent VEE Pro 99 Chapter 10 IVI Architecture Chapter 11 Advanced Topics Now that you ve seen how to create a short program to perform a measurement in popular programming environments we want to introduce a few advanced IVI topics architecture requirements for interchangeability Configuration Store and future developments These should broaden your view of the capabilities of IVI drivers Up to this point we ve focused on using either an IVI COM or IVI C driver from a specific ADE The schematic below illustrates the use model for IVI drivers that was deployed in the previous chapters This use model is the simplest method of using an IVI driver but does not enable interchangeability This section explains the architecture including the capabilities of the various driver types and their contribution to interchangeability Driver API To support popular programming languages and development environments IVI drivers provide either an IVI COM or an IVI C API Driver developers may provide both interfaces as well as wrapper interfaces that improve usability in specific development environments The IVI COM driver uses a standard Component Object Model COM interface that provides access to the functions defined in the class through a hierarchy of methods and properties The IVI C driver appears as a dynamic link library DLL such as Windows DLL composed of standard C f
81. rom the ActiveX subpalette and select the appropriate property or you can use the Class Browser for both IVI C and IVI COM drivers Demo 0 Block Diagra File Edit View Project Operate Tools Window Help E amp e nl 9 es balls 13pt Application Font tor iar e 2 2 GPIB 23 INSTR f ResourceName IdQuery ISimulate 1 OptionString Initialize rb Reset Configure the Instrument 1 Go back to the Class Browser and under Properties and Methods double click the DC Voltage property and select the Configure method Click Create and drag the Invoke Node to the Block Diagram Create constants and enter values to set the Resolution to 1 millivolt and the Range to 1 5 volts e 0 001 in the Resolution field 1 5inthe Range field TM Using IVI with LabVIEW 3 Connect the automation refnum and error terminals from Initialize Invoke Node to DCVoltage Configure Invoke Node 4 Inthe Class Browser go back to the top level object and double click the Trigger property and select the Delay property Click Create Write and drag the Property Node to the Block Diagram 5 Create a constant and enter a value of 0 01 seconds for the Delay field 6 Connectthe automation refnum and error terminals from DCVoltage Configure Invoke Node to Trigger Delay Property Node Take the Reading 1 Return to the Class Browser and under Properties a
82. rs Check Open Unload and Disable CEM Logging Click OK The CEM Wizard dialog appears Right click on DMM and click on Add Interface Function The Add Function s to Action s dialog appears For Setup select Setup in the Action s dialog and enter DMM Setup in the User Function Name s field Click OK For Fetch and Init select the appropriate action in the Action s dialog and enter DMM Fetch and DMM Init in the User Function Name s field Click OK Note This will add several files to your WCEM module ctrl cpp DMM cpp Error cpp Wrapper cpp and Key h ctrl cpp includes the doOpen and doUnload functions Dmm cpp includes the three DMM functions misa PLO eo ef etd noel 3 aaj e i e eiv eles laste tl 001010 REQUIRE CONTROL VOLTAGE RANGE 300 V TO 300 V DMM DC VOLTS SENSOR VOLTAGE DC S Jr i MAX TIME RANGE 1 SEC TO 5 SEC fa nasa CNX HI LO A cs n T 001110 DECLARE VARIABLE MEASURED IS DECIMAL cs par o E02000 OUTPUT C LF ATLAS PROGRAM STARTS HEREMLF CS h ag 002100 VERIFY VOLTAGE INTO MEASURED bM ie n DC SIGNAL USING DMM DC VOLTS a wan NOM 0 V UL 0 5 V LL 0 5 V poe VOLTAGE RANGE 0 5 V TO 0 5 V 5 error eco MAX TIME 5 SEC L pisi CNX HI X20 2 LO X20 3 002200 OUTPUT C DC VOLT MEASUREMENT 1 MEASURED Uu WCEM cs pens iai 999000 OUTPUT C SLFSATLAS PROGRAM ENDS HERESLFS c P ct 999999 TERMINATE A
83. s dialog IVI Dmm in the IVI DMM panel field e Agilent34401 in the device type field GPIB and 23 in the VISA connect string field DCV in the measurement mode field e 1 5 in the range field 0 001 in the resolution field Note Capabilities that are unavailable are grayed out 7 Click Next e Enter the name of the IvI DMM panel ivi2_ II Dmm e Select the device type from the list of installed devices Agilent34401 vl eEnterthe IP number or DNS name and VISA connect strings GPIB v 23 ws Connect Selectthe measurement mode from the list DEY na Enter the range V 19 ul eEnterthe resolution V I e Selectthe autozero mode from the list Sutozero off gm si tese Hi e 8 Configure the operating mode Select Auto refresh and enter 1000 in the update rate field Using IVI with Measure Foundry amp ee0ee90e8 o N 68 11 12 13 Control Source Chapter 7 ONO 5 Q Click Next Configure the trigger delay In the Properties dialog enter 0 01 in the trigger delay field and Immediate in the trigger source field Click Next Configure the option string reset and reading timeout to 1 second In the Properties dialog enter the following e Simulate true in the IVI connect option string e 1000 in the timeout field Check the Reset on Connect box Click Next The property pages contain the information nece
84. sion We do not need to make any modifications to the application itself All changes are contained within the Configuration Store Below we show examples of using interchangeability using logical names with IVI COM and IVI C as Y 00 So Vendor Y DMM GP1IB0 23 INSTR Vendor Y DMM IVI COM Driver IVI Configuration Store Logical Name DMM Driver Session Vendor X DMM Hardware Asset GPIB1 21 INSTR Software Module Vendor X DMM IVI COM Driver Driver Session Vendor Y DMM Hardware Asset GPIBO 23 INSTR Software Module Vendor Y DMM IVI COM Driver IVI COM This C example shows interchangeability using IlviDriver which references all of IVI s inherent capabilities llviDriver Create a string variable for logical name string logicalName AgilentDriver Add a reference to the Session Factory Go to Project and Add Reference Select the IVI Session Factory Type Library under the COM tab Create an instance of the Session Factory IIviSessionFactory factory new IviSessionFactoryClass Set the type to match the referenced IVI Instrument Class for class interchangeability This example uses llviDriver because it is common to all drivers This uses the Session Factory to create a driver based on the logical name AgilentDriver In the Configuration Store logical name AgilentDriver points to a driver session The driver session points to a software module which can be
85. ssary to label the button and specify how it controls the program In the Foundry window select Application Control Drag and drop the Control Button to the form Double click the Control Button The Properties of Control Button dialog appears Enter Start Stop in the text field Select the switch button type and click Next Scroll the list of Available items for the IVI Dmm and click Actions Select Actions and click the double arrow to add to Item sequence Select Start autorefresh from the drop down list in Active value Select Stop autorefresh from the drop down list in Passive value e vailable items e item sequence ivi2 IvI Dmm Form ACDCI AutaZero Givi IVl Dmm ACDCI Frequency by Actions ACDCI Frequency bv ACDCI Range ACDCI Resolution ACDCY AutoZero ACDCY Frequency ACDCY Frequency ACDCV Range ACDCY Resolution ACI AutoZero ACI Frequency Max ACI Frequency Min ACI Range ACI Resolution ACY AutoZero ACY Frequency Ma ACY Frequency Min ACY Range ACY Resolution Component State DCI AutoZero DCI R ange DCI Resolution DCV AutaZero iv alma Ee alt Active value Start autorefresh Iv C Show all components Passive value Stop autorefresh x Add the properties you want to control In the Active value section specify the value that vou want to assign to the property hen the button is pushed down The Passive value can be used when you have selected a switch button Kane Actual value No
86. sset Driver session 11 Select File and Save IVI Configuration Store Saving to the store may take several moments 12 Close the Test amp Measurement Tool Generate an Instrument Wrapper We will now automatically generate an instrument driver wrapper file mdd so that MATLAB can use the IVI driver At the MATLAB command prompt type makemid dmm The file dmm mdd appears in the current directory window This is the instrument wrapper created by the makemi d command You may now use MATLAB to communicate with your instrument through an IVI driver Note To help you learn the structure of a driver faster MATLAB provides autocompletion support As you are typing your commands for a driver press the Tab key to get a selection of possible completions You can also use the command get to see a list of possible properties and methods to get a list of methods on the object methodsview will give you a graphical display of the methods also Configure and Control the Instrument You can interact with the instrument by using the Test amp Measurement Tool or the MATLAB command line We use the MATLAB command line here Note All MATLAB methods and properties are available at the command line Create an Instance of the Instrument To create an instance of the instrument type myDmm icdevice dmm Connect to the Instrument Similar to the Initialize command in most ADEs the Connect command in MATLAB initializ
87. th a consistent and high standard of quality usability and completeness The specifications define an open driver architecture a set of instrument classes and shared software components Together these provide consistency and ease of use as well as the crucial elements needed for the advanced features IVI drivers support instrument simulation automatic range checking state caching and interchangeability The IVI Foundation has created IVI class specifications that define the capabilities for drivers for the following eight instrument classes Class IVI Driver Digital multimeter DMM lviDmm Oscilloscope lviScope Arbitrary waveform function generator lviFgen DC power supply IviDCPwr Switch lviSwitch Power meter IviPwrMeter Spectrum analyzer lviSpecAn RF signal generator IviRFSigGen IVI Class Compliant drivers usually also include capability that is not part of the IVI Class It is common for instruments that are part of a class to have numerous functions that are beyond the scope of the class definition This may be because the capability is not common to all instruments of the class or because the instrument offers some control that is more refined than what the class defines IVI also defines custom drivers Custom drivers are used for instruments that are not members of a class For example there is not a class definition for network analyzers so a network analyzer driver must be a custom driver Custom drivers provide
88. the Configuration Store logical name LineVoltage points to a driver session The driver session points to a software module which can be any IVI COM driver The Session Factory creates an instance of the driver and returns a reference to the instance of the driver This line of code then casts the reference returned to type IlviDmm from which all of IVI DMM s class compliant features can be referenced IIviDmm dmm IIviDmm factory CreateDriver logicalName Initialize is required because the session factory does not take care of that function dmm Initialize logicalName false false simulate true The rest of the code follows that used for the examples but note that it is written to the class compliant interfaces not the instrument specific ones dmm Configure IviDmmFunctionEnum IviDmmFunctionDCVolts 1 5 0 001 dmm Trigger Delay 0 01 Console WriteLine dmm Measurement Read 1000 ToString dmm Close IVI C This C example shows how to use an IVI C Class Driver to achieve interchangeability It is very similar to the IVI C examples in Chapters 2 and 5 except for 3 differences The function calls are all for the class driver and do not refer to the particular instrument being used e g IviDMM Read vs HP34401A Read The parameters in certain function calls are generic for the instrument class and do not refer to the particular instrument being used e g IVIDMM VAL DC VOLTS vs HP34401A VAL DC VO
89. the Configuration subpalette select Configure Measurement VI and place it on the Block Diagram 2 Create constants and enter values to set the resolution to 1 millivolt the function to DC Voltage and the range to 1 5 volts 0 001 in the Resolution field DC volts in the Measurement Function field 1 5 in the Range field 3 Connect the instrument handle and error terminals from Initialize With Options VI to Configure Measurement VI 4 From the Trigger subpalette select Configure Trigger VI and place it on the Block Diagram 5 Connect resource name and error information from Configure Measurement VI to Configure Trigger VI 6 Create a constant and enter a value of 0 01 in the Trigger Delay field Note You can also set the Trigger Delay using a Property Node by replacing steps 4 amp 5 with a property access as shown in the section Setting a Property in an IVI C Driver below Take the Reading 1 Return to the main hp34401a palette From the Measurement subpalette select Read VI and place it on the Block Diagram 2 Set the value for Timeout to 1 second 1000 ms Enter 1000 in the Timeout field Chapter 4 3 Connect resource name and error information from Configure Trigger to Read VI Display the Reading Create an indicator for Reading from the terminal on the Read VI Close the Session 1 Return to the main hp 34401a palette Select Close VI and place it on the Block Diagram 2 Connect resource name and error inform
90. the function and values into your program Close the function panel The hp34401a ConfigureTrigger function appears in your program Set the itn Timeout From the library tree select Measurement and click Read The Read dialog opens 2 Set the value for Timeout to 1 second 1000 ms and instrument handle to session Enter 1000 in the Read field Using IVI with LabWindowsTM CVITM 53 54 session in the Instrument Handle field Display the Reading 1 Select the Reading parameter 2 Select Code and click Declare Variable The Declare Variable dialog appears 3 Enter reading in the Variable Name field 4 Check the boxes titled Execute declaration in Interactive Window and Add declaration to top of target file c Click OK 5 Select Code and click Insert Function Call to insert the function and values into your program Close the function panel The hp34401a Read function appears in your program Close the Session 1 2 3 Chapter 5 From the library tree select Close The Close function panel opens Enter session in the Instrument Handle field Select Code and click Insert Function Call to insert the function and values into your program Close the function panel The hp34401a Close function appears in your program Your final program should contain the code below include lt ansi_c h gt include hp34401a h include lt cvirte h gt static ViReal64 reading static ViSession session int main int argc ch
91. the same consistency and benefits described below for an IVI driver except interchangeability Introduction eccccc6 IVI drivers conform to and are documented according to the IVI specifications and usually display the standard IVI logo Note For more information on the types of IVI drivers refer to Chapter 11 Advanced Topics Why Use an IVI Driver Chapter 1 Why choose IVI drivers over other possibilities Because IVI drivers can increase performance and flexibility for more intricate test applications Here are a few of the benefits Consistency IVI drivers all follow a common model of how to control the instrument That saves you time when you need to use a new instrument Ease of use IVI drivers feature enhanced ease of use in popular Application Development Environments ADEs The APIs provide fast intuitive access to functions IVI drivers use technology that naturally integrates in many different software environments Quality IVI drivers focus on common commands desirable options and rigorous testing to ensure driver quality Simulation IVI drivers allow code development and testing even when an instrument is unavailable That reduces the need for scarce hardware resources and simplifies test of measurement applications The example programs in this document use this feature Range checking IVI drivers ensure the parameters you use are within appropriate ranges for an instrument St
92. trademark of The MathWorks Inc Using IVI with MATLAB 63 64 Chapter 6 Chapter 7 Using IVI with Measure Foundry The Environment Measure Foundry is a visual software environment for creating test and measurement control and analysis applications The design environment consists of forms and the foundry window You choose components from the foundry window and drop them onto your form Clicking on the components accesses property pages where you can set design configuration and connectivity This enables fast application development Each application consists of three primary elements e a data source supplies data to the application acontrol source determines how and when the data is used adata sink receives data to process or display Example Requirements Measure Foundry 5 Agilent 34401A IVI COM Version 1 1 0 11 March 2006 from Agilent Technologies Agilent IO Libraries Suite 14 2 Download and Install the Driver If you have not already installed the driver go to the vendor Web site and follow the instructions to download and install it You can also refer to Chapter 1 Download and Install IVI Drivers This example uses an IVI COM driver IVI COM is the preferred driver for Measure Foundry IVI C is not supported Note You cannot specify an instrument in Measure Foundry unless you have already installed the appropriate driver If you need to download and install a driver you do not need to exit
93. uire S VXIPNPPATH WinNT include 8 Click OK Note These initial steps need only be done once for each computer you use All subsequent Visual Studio projects will continue to use these settings and will be able to locate your IVI COM drivers 9 Select Project and click Properties The IVIDemo cpp Property pages dialog box appears Using IVI with Visual C eoeecee N 24 Options E Environment Platform Performance Tools Win32 Projects and Solutions General Show directories For Include files Executable files Include files Reference files Build and Run vCInstallDirinclude VB Defaults VCInstallbirJatlmfclinclude VC Directories vCInstallDir PlatFormSDKlinclude C Project Settings FrameworkSDKDir include c Program Files Ivi Include Source Control c WXIPNPAWinNTIinclude Text Editor DevPartner Business Intelligence Designers Database Tools Debugging lt f EE H E Library files Source files Exclude directories Device Tools HTML Designer Include Directories Microsoft Office Keyboard Setting y amp l amp E E5 10 Expand Configuration Properties 11 Expand Linker Path to use when searching For include Files while building a VC4 project Corresponds to environment variable INCLUDE 12 Select Input In the Additional Dependencies field type hp34401a lib 13 Select OK 14 T
94. unctions The C specifications also define components such as error handling and driver session creation and management which ensure robustness and interoperability The easiest interface to use in a given Application Development Environment is one that is native to the environment So a C interface works best in C and a COM interface in Visual Basic Some ADEs support only one type of interface however which makes the choice simple Chapter 11 Driver developers also provide wrapper interfaces optimized for specific development environments The wrapper functions as an adapter between an ADE and a driver not designed for that ADE It enables the ADE to use technologies for which no native implementation exists In Chapter 6 IVI with MATLAB for example generating an instrument wrapper is a key step in creating the program Driver Types The schematic on the next page shows the three basic types of drivers Both IVI COM and IVI C use Custom and Class Compliant Drivers but Class Drivers are unique to IVI C Usually you only need to be concerned about the type of driver if you want to enable interchangeability To understand the differences among them you first need to understand the various capabilities these drivers support Inherent capabilities capabilities required by the IVI Foundation such as instrument simulation state caching interchangeability checking and range checking as well as commands such as Initialize Reset and C
95. ware Asset and indicate whether you want to use Simulation Mode or other optional parameters when connecting 6 Select the Driver Sessions tab In the Driver Sessions dialog select Add and enter the following DMM in the Name field This session matches the Agilent 34401 driver with the hardware asset of GPIBO 23 and turns on Simulation mode of the driver in the Description field optional 7 Select Agilent34401 in the Software module drop down list Select myDMM in the Hardware asset drop down list 9 Check Simulate in the options Using IVI with MATLAB 59 60 Chapter 6 Configuration store C Program FlestIVIVDataliviConfiguraticnStore xnl Logical Names Driver Sessions Software Modules Hardware Assets Name Description his session matches the Agilent 34401 driver with the hardware asset of 160 23 and turns on Simulation 10 Select the Logical Names tab In the Logical Names dialog select Add and enter the following DMMin the Name field This logical name enables your program to access any DMM independent of manufacturer or hardware asset in the Description field optional DMM in the Driver session field Configuration store C Program Files IVI Data IviConfigurationStore xml Logical Names Driver Sessions Software Modules Hardware Assets Name Description is logical name enables your program to access any DMM independent manufaturer or hardware a
96. window In the DMM_Setup interface function insert the following code below the line Please insert your CEM driver code here hr if hr driver gt put_Function Agilent34401FunctionDCVolts FAILI Displ put F ED hr ay N033 30 41m Bad return from unction Agilent34401FunctionDCVolts method 033 m n driver get DCVoltage amp pDMMDCVolt Using IVI with PAWS 79 80 Chapter 8 if FAILED hr Display 033 30 41m Bad return from get_DCVoltage amp pDMMDCVolt method 033 m n hr pDMMDCVolt Configure 1 5 0 001 if FAILED hr Display 033 30 41lm Bad return from gt Configure 1 5 0 001 method 033 m n To set the trigger delay to 0 01 select the DMM cpp file from the PAWS Project window In the DMM_Tnit interface function insert the following code below the line Please insert your CEM driver code here hr driver gt get_Trigger amp pDMMTrig if FAILED hr Display 033 30 41m Bad return from get Trigger amp pDMMTrig method 033 m n hr pDMMTrig Configure Agilent34401TriggerSourceImmediate 0 01 if FAILED hr Display 033 30 41m Bad return from Configure Agilent34401TriggerSourceImmediate 0 01 method 033 m n hr driver gt get_Measurement amp pDMMData if FAILED hr Display 033 30 41m Bad return from get Measurement amp pDMMData meth

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