delivering interchangeability and more autotestcon 2012 anaheim, ca september 10-13, 2012

Delivering Interchangeability and More

AUTOTESTCON 2012Anaheim, CASeptember 10-13, 2012

Agenda

IVI Basics and Background IVI Architecture IVI Shared Components Why IVI? IVI-COM, IVI.NET and IVI-C

www.ivifoundation.org

http://www.ivifoundation.org/

IVI Background Open consortium

End-users System integrators Instrument and software vendors

Founded in August 1998, incorporated in March 2001 26 member companies Consolidated home for many SW standards

IVI Instrument Drivers VISA VXIplug&play SCPI LXI Synchronization



What is IVI?


The primary purpose of the Consortium is to• Promote the development and adoption of

standard specifications for programming test instrument

• Focus on the needs of the people that use and develop test systems who must take off-the-shelf instrument drivers and build and maintain high-performance test systems

• Build on existing industry standards to deliver specifications that simplify interchanging instruments and provide for better performing and more easily maintainable programs

The primary purpose of the Consortium is to• Promote the development and adoption of

standard specifications for programming test instrument

• Focus on the needs of the people that use and develop test systems who must take off-the-shelf instrument drivers and build and maintain high-performance test systems

• Build on existing industry standards to deliver specifications that simplify interchanging instruments and provide for better performing and more easily maintainable programs

From IVI Foundation By-laws


IVI’s Fit with Other Specs

SCPI

GPIB VXIAXIe 1.0

PXI

Physical Connection

LXI

PCI, PCIe &Compact PCI

Ethernet VMEGPIB

T&M Specific Needs

IO Interfaces &SW Protocols

VXI-11HiSLIP

VXIplug&play

PXI-2 and PXI-6: Software

VISAmessage register

IVI 6.3 PXI plug-in

USB TMC

USB

IVI 3.x (Arch)C COM .NET

IVI 4.x(Classes)

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InstrumentCapabilities

AXIe 2.0

AXIe 3.1

What is IVI – Really?? Architecture specifications Instrument class specifications A library of shared software components


Architecture Specifications3.1,3.2,3.3,3.4,3.5,3.6,3.9,.3.10,3.12,3.17,3.18

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13 specs @ ~220 pages


Goals of the IVI Foundation


Hardware Interchangeability Simplify replacing an instrument from a system with a similar one Preserve test software when instruments become obsolete Simplify test code reuse from design validation to production test

Quality Improve driver quality Establish guidelines for driver testing and verification

Software Interchangeability Provide an architectural framework that allows users to easily integrate

software from multiple vendors Provide standard access to driver capabilities such as simulation, state

caching, range checking and coercion Provide consistent instrument control in popular programming

environments


IVI Membership Benefits

Influence the development of standards Participate in and access future standards Share ideas with developers, users, system

integrators and vendors Access source code for shared components Participate in interoperability sessions Network with test and measurement industry

leaders



Approved Instrument Classes

DC power supply AC power supply DMM Function generator Oscilloscope Power meter RF signal generator

Spectrum analyzer Switch Upconverter Downconverter Digitizer Counter/timer



Driver Architecture Spec’s IVI-3.1: Driver Architecture Specification IVI-3.2: Inherent Capabilities Specification IVI-3.3: Standard Cross-Class Capabilities Specification IVI-3.4: API Style Guide IVI-3.5: IVI Configuration Server Specification IVI-3.6: COM Session Factory Specification IVI-3.9: C Shared Components IVI-3.12: Floating Point Services Specification IVI-3.14: Primary Interop Assembly Specification IVI-3.15: IviLxiSync Specification IVI-3.17: Installer Requirements Specification IVI-3.18: IVI.NET Utility Classes and Interfaces Specification



IVI Driver Features

Simulation Required of all IVI drivers Very useful for testing in new ADEs Helpful when instruments are difficult to procure

State caching Range checking Coercion

Coercion recording All extended features enabled and accessed in a

standard fashion



IVI Shared Components

C Shared Components Floating Point Services IVI-COM Session Factory Configuration Server COM Type Libraries .NET PIAs IVI.NET Shared Components



IVI Conformance Basic conformance

Follows all architecture specs Implements inherent capabilities defined in IVI-3.2. Not one of the classic instrument types No class-compliant functionality (none of the IVI-4.X specs apply) Can be advertised as fully IVI compliant

Instrument-class conformance Basic conformance + one or more instrument class APIs (IVI-4.X

specs)



What is IVI Compliant -Really?? Standard install location and process Support for IVI Features Common API for common tasks

~40 common functions Simulation, Caching, Open, Close, Initialize, SW

Trigger, Status check, Version check …..

Consistent APICommon types, Name generation,

Organization



What is IVI Class Compliant - Really?? Adds Class Compliant API Instrument API same as other instruments Custom API still available

Especially for capabilities beyond the class Simplifies swapping instruments

ww.ivifoundation.org IVIFoundation.org


Why IVI – One Driver to Rule them All Much more than interchangeability Arguably the biggest benefit is the ability to provide one

driver and give users a first class experience in nearly all ADEs Visual Basic 6 Visual C++ Visual C# and Visual Basic.NET VBA (Excel, Word, PowerPoint) MATLAB LabVIEW LabWindows/CVI Agilent VEE



Why IVI? – Uniform Way of Doing Common Tasks Avoids frustrations of arbitrary differences Instantiation, initialization, shutdown Controlling driver features – state caching, error query, simulation,

etc. Configuration and installation

No need to dig thru header files, registry settings, help or readme One place to reliably set the I/O address is a big benefit

Standard mechanism for handling multi-channel devices aka repeated capabilities in IVI parlance

Standard error reporting No need to deal with the numerous possible error schemes

Versioning standards



Why IVI – Tools, Tools, Tools Far easier to develop an IVI driver with a tool than it is to

develop a customer driver without a tool Common requirements enable tools

Leads to better, cheaper drivers Driver is much more than a DLL w/ function exports

Help files Installer

IVI 3-17 dedicated to IVI installers and is 53 pages Regression test apps / Unit test apps Special components for .NET

XML IntelliSense file interop assembly version policy files



Why IVI – Tracking the Standards Vendors relieved from onerous task of keeping pace with

multiple moving targets Windows OSs, Windows help, Windows installer, Windows API,

security, .NET platform Six versions of Visual Studio since IVI Vista and UAC was a major challenge for IVI 64-bit OS support took two years within IVI

IVI member companies bring experts to meetings to ensure IVI solutions work with their hardware Users of IVI directly leverage R&D efforts of NI, Agilent, R&S, etc.



API Standards in IVI IVI specifications layout three APIs

IVI .NET IVI-COM IVI-C

Many considerations for both driver developers and end users when choosing which technology to use Driver developer environment Custom environment Others…(more on this later)

IVI specs also define how to build driver wrappers Allows one code base while supporting IVI-C, IVI-COM and IVI .NET

APIs IVI-COM on top of IVI-C (not common) IVI-C on top of IVI-COM (very common in today’s IVI drivers)



Simple IVI-COM Driver Usage in Visual Basic


Dim driver as New Agilent54600Dim scope as IIviScopeSet scope = driver

scope.Initialize “GPIB::10”, False, False, “”

scope.Trigger.Level = 3.4 ‘setting a numeric propertyscope.Trigger.Type = IviScopeTriggerEdge ‘setting an enum property

scope.Measurements.Initiate ‘calling a method

scope.Close


Simple IVI-C Driver Usage


// NOTE: Error checking not shown#include “ag54600.h”

int _tmain(int argc, _TCHAR* argv[]){ ViSession vi; ViStatus viStatus = ag54600_init(“GPIB::10”, VI_FALSE, VI_FALSE, &vi);

viStatus = ag54600_SetAttributeViReal64(vi, “”,AG54600_ATTR_TRIGGER_LEVEL, 3.2);

viStatus = ag54600_SetAttributeViInt32(vi, “”,AG54600_ATTR_TRIGGER_TYPE, AG54600_VAL_EDGE_TRIGGER);

viStatus = ag54600_InitiateAcquisition();

viStatus = ag54600_close();}


Motivations for IVI.NET Present an API more suited to .NET developers Simplify source code

Allow end users to understand instrument behavior by examining driver source

Allow end users to fix bugs on their own Allow end users to add features to drivers on their own

Richer, more expressive APIs More flexibility with API data types Clean handling of asynchronous notifications (aka “events”)

Side-by-side deployment of drivers Only one version of an IVI-COM or IVI-C driver can be installed at a

time IVI.NET allows multiple versions of a driver to be installed



Richer Type System in IVI.NET Both IVI-COM and IVI-C drivers suffer from a limited set of data

types Integers, floats, Booleans, strings Arrays of the above, but extra parameters are required in IVI-C

IVI-C cannot expose an array of strings IVI-C cannot expose structs

Can be done in IVI-COM, but it’s tedious to implement


IviScope_FetchWaveform(ViSession vi,ViConstString channel,ViInt32 waveformSize, // # of elements on inputViReal64 waveform[], // actual data bufferViInt32 *actualPoints, // # of elements on outputViReal64 *initialX,ViReal64 *xIncrement);


Simplifying APIs with .NET Types


IviDigitizer_FetchWaveformReal64(ViSession Vi,ViConstString ChannelName,ViInt64 WaveformArraySize,ViReal64 WaveformArray[],ViInt64* ActualPoints,ViInt64* FirstValidPoint,ViReal64* InitialXOffset,ViReal64* InitialXTimeSeconds,ViReal64* InitialXTimeFraction,ViReal64* XIncrement);

IVI-C signature

Channels[].Measurement.FetchWaveform(IWaveform<Double> waveform)

IVI.NET signature


Simplified Usage Syntax


digitizer.Arm.Sources.get_Item("LAN3").Detection = IviLxiSyncArmSourceDectionEnum.IviLxiSyncArmSourceDetectionHigh;

C# client using IVI-COM driver through interop

C# client using IVI.NET driverdigitizer.Arm.Sources["LAN3“].Detection = ArmSourceDetection.High;

Simplified access to very commonly used features Enums Repeated capabilities (e.g. “channels”)


Shared IVI.NET Data Types IVI Foundation felt it would be useful to offer commonly used data types as

part of the IVI.NET Shared Components Increase consistency amongst IVI.NET drivers Facilitate data interchange between drivers

Standardized IWaveform and ISpectrum interfaces Digitizers and scopes and RF spectrum analyzers all read waveforms Function generators and RF signal generators source waveforms Without a common definition of a “waveform”, client applications would need to

write the tedious code to translate between each class’s notion of a waveform Time-based parameters can use PrecisionDateTime and

PrecisionTimeSpan No confusion about ms vs sec, absolute vs relative time, UTC time, etc Precision adequate for IEEE 1588 devices

Common trigger source data type Useful in “stitching” together devices in triggered source-measure operations



Additional Information

For more information or to join, go to our webpage at:


Additional Resources: IVI Getting Started Guide on our Home page or Resources page

Either in in short pdf files for the ADE that you prefer Or, single pdf file that includes eight different ADEs

Tutorial Videos Coming Soon: IVI Getting Started Guide tutorial videos in the ADE you prefer.




delivering interchangeability and more autotestcon 2012 anaheim, ca september 10-13, 2012

Documents

ivi foundation

usb tmc usb ivi

agenda ivi basics

instrument capabilities

pages slide

preserve test software

hislip vxi plugplay

high performance test