VIRTUAL INSTRUMENTATION

SUBMITTED BY,

JITHIN K MOHANDAS ROLL NO : 29 13030476 EEE S5

ACKNOWLEDGEMENT

I extend my sincere thanks to Mr.Babu P Head of Department for providing me with guidance and facilitate for the seminar.I express sincere gratitude to seminar coordinator Mr.Anilkumar G.S staff in charge, for their cooperation and guidance preparing and presenting the seminar.I extend my sincere thanks to all other faculty members of Electrical and Electronics Department and my friends for their support and encouragement.

ABSTRACT Every parameter in the industry or laboratory needs measurement. For measuring those quantities dedicated instruments are more often used. These instruments provide very accurate measurement and are reliable. But they cannot be customized. They are very much useful in industries but they cannot meet the requirements of scientists and research workers. A virtual instrument overcomes the drawbacks of traditional instruments. Virtual instruments are fueled by the rapid advancement of the chip technology and in PC. Virtual instruments represent a fundamental shift from traditional hardware-centered instrumentation system to software-centered systems that exploit the computing power, productivity, display and connectivity capabilities of popular desktop computers and workstations. Virtual instruments are real instruments, real world data is collected, recorded and displayed, it just uses the data acquisition capabilities, processing, storage and other capabilities of a computer.

TABLE OF CONTENTS

SL NO1. INTRODUCTION2. CONCEPT OF VIRTUAL INSTRUMENT3. WHY HAS VIRTUAL INSTRUMENTATION BEEN SO SUCCESSFUL4. VIRTUAL INSTRUMENTATION AND ITS NECESSITY5. LAYERS OF VIRTUAL INSTRUMENTATION SOFTWARE6. VIRTUAL INSTRUMENTATION FOR TEST7. VIRTUAL INSTRUMENTATION FOR INDUSTRIAL I/O AND CONTROL8. VIRTUAL INSTRUMENTATION FOR DESIGN9. TRADITIONAL INSTRUMENT V/S VIRTUAL INSTRUMENT10. CAPABILITIES OF VIRTUAL INSTRUMENTATION HARDWARE11. LabVIEW12. APPLICATIONS13. CONCLUSION

INTRODUCTION In industries we find many parameters to be controlled, and many electronic instruments are used to control these parameters. All these instruments are dedicated to measure or control those parameters only. They entirely differ from one another but they have one thing in common, they all are box shaped and has some controls and knobs on them. the Stand-alone electronic instruments are very powerful, expensive and designed to perform one or more specific tasks defined by the vendor. The user cannot extend or customize them. The knobs and buttons, built-in circuitry and the functions available to the user, all of these are specific to the nature of the instrument. In addition, special technology and costly components must be developed to build these instruments. Widespread adoption of the PC over the past twenty years has given rise to a new way for scientists and engineers to measure and automate the world around them. One major development resulting from the advancement of the PC is the concept of virtual instrumentation. A virtual instrument consists of an industry-standard computer or workstation equipped with off-the-shelf application software, cost effective hardware, which together performs the function of traditional instruments. Today virtual instrumentation is used by engineers and scientists for faster application development, higher quality products at lower costs. Virtual instruments represent a fundamental shift from traditional hardware-centered instrumentation systems towards software-centered systems that exploit the computing power, productivity, display and connectivity capabilities of popular desktop computers and workstations. Even if PC and IC technologies experienced a good growth, it is the software that makes a reality of building virtual instruments.

CONCEPT OF VIRTUAL INSTRUMENTUsually instrumentation manufactures provide specific functions to given architecture and fixed interfaces for measuring devices, and thus limit the application domain of these devices. In actual use much time is required for adjusting the measuring range and for saving and documenting the results. The advent of microprocessors in the measurement and instrumentation fields produced rapid modifications of measuring device technology, soon followed by the appearance of computer based measurement techniques. These techniques consists of three parts as shown in fig-1, acquisition of measurement data, conditioning and processing of analysis of measurement signals and presentation of data.

The concept of virtual instrument is frequently used in industrial measurement practice, but not always with precisely the same meaning. In one view virtual instruments are based on standard computers and represent systems for storage, processing and presentation of measurement data. In another view, a virtual instrument is computer equipped with software for a variety of uses including drivers for various peripherals, as well as A to D and D to A converters, representing an alternative to extensive conventional instruments with analog displays and electronics. Acquisition of data by a computer can be achieved in various ways and for this reason the understanding of architecture of the measuring instrument becomes important.A virtual instrument can be defined as an integration of sensors by a PC equipped with specific DAC hardware and software to permit measurement data acquisition, processing and display. Virtual instruments are a means of integration of the display, control and centralization of complex measurement systems. Industrial instrumentation applications however require high rates, long distances and multi vendor instrument connectivity based on open industrial network protocols. In order to construct a virtual instrument it is necessary to combine the hardware and software elements which should perform data acquisition and control, data processing and data presentation in a different way to take maximum advantage of the PC, as shown in fig-2. Virtual instrumentation can use the serial communication based on RS-232 standard or the parallel communication based on GPIB standard, PC bus or VXI bus.

WHY HAS VIRTUAL INSTRUMENTATION BEEN SO SUCCESSFUL? Virtual instrumentation achieved mainstream adoption by providing a new model for building measurement and automation systems. Keys to its success include rapid PC advancement; explosive low-cost, high-performance data converter (semiconductor) development; and system design software emergence. These factors make virtual instrumentation systems accessible to a very broad base of users.

PC performance, in particular, has increased more than 10,000X over the past 20 years. Virtual instruments takes advantage of this PC performance increase by analyzing measurements and solving new application challenges with each new-generation PC processor, hard drive, display, and I/O bus. These rapid advancements, combined with the general trend that technical and computer literacy starts early in school, contribute to successful computer-based virtual instrumentation adoption. Standard hardware platforms that house the I/O are important to I/O modularity. Laptop and desktop computers provide an excellent platform where virtual instrumentation can make the most of existing standards such as the USB, PCI, Ethernet, and PCMCIA buses. Using these standard buses, National Instruments can focus on measurement hardware innovation while benefiting from inevitable PC platform innovation (for example, USB 2.0 and PCI Express).

Figure 2. Modular I/O and scalable platforms such as USB, PCI, and PXI provide flexibility and scalability.VIRTUAL INSTRUMENTATION AND ITS NECESSITY With virtual instrumentation, software based on user requirements defines general-purpose measurement and control hardware functionality. Virtual instrumentation combines mainstream commercial technologies, such as the PC, with flexible software and a wide variety of measurement and control hardware, so engineers and scientists can create user-defined systems that meet their exact application needs. With virtual instrumentation, engineers and scientists reduce development time, design higher quality products, and lower their design costs.

Figure 1. Virtual instrumentation combines productive software, modular I/O, and scalable platforms.

Today, virtual instrumentation has reached mainstream acceptance and is used in thousands of applications around the world in industries from automotive, to consumer electronics, to oil and gas.

NECESSITY

Virtual instrumentation is necessary because it delivers instrumentation with the rapid adaptability required for todays concept, product, and process design, development, and delivery. Only with virtual instrumentation can engineers and scientists create the user-defined instruments required to keep up with the worlds demands.

To meet the ever-increasing demand to innovate and deliver ideas and products faster, scientists and engineers are turning to advanced electronics, processors, and software. Consider a modern cell phone. Most contain the latest features of the last generation, including audio, a phone book, and text messaging capabilities. New versions include a camera, MP3 player, and Bluetooth networking and Internet browsing.

The increased functionality of advanced electronics increased functionality is possible because devices have become more software centric. Engineers and scientists can add new functions to the device without changing the hardware, resulting in improved concepts and products without costly hardware redevelopment. This extends product life and usefulness and reduces product delivery times. Engineers and scientists can improve functionality through software instead of developing further specific electronics to do a particular job.

However, this increase in functionality comes with a price. Upgraded functionality introduces the possibility of unforeseen interaction or error. So, just as device-level software helps rapidly develop and extend functionality, design and test instrumentation also must adapt to verify the improvements.

The only way to meet these demands is to use test and control architectures that are also software centric. Because virtual instrumentation uses highly productive software, modular I/O, and commercial platforms, it is uniquely positioned to keep pace with the required new idea and product development rate. National Instruments LabVIEW, a premier virtual instrumentation graphical development environment, uses symbolic or graphical representations to speed up development. The software symbolically represents functions. Consolidating functions within rapidly deployed graphical blocks further speeds development.

Another virtual instrumentation component is modular I/O, designed to be rapidly combined in any order or quantity to ensure that virtual instrumentation can both monitor and control any development aspect. Using well-designed software drivers for modular I/O, engineers and scientists quickly can access functions during concurrent operation.

The third virtual instrumentation element using commercial platforms, often enhanced with accurate synchronization ensures that virtual instrumentation takes advantage of the very latest computer capabilities and data transfer technologies. This element delivers virtual instrumentation on a long-term technology base that scales with the high investments made in processors, buses, and more.In summary, as innovation mandates software use of to accelerate new concept and product development, it also requires instrumentation to rapidly adapt to new functionality. Because virtual instrumentation applies software, modular I/O, and commercial platforms, it delivers instrumentation capabilities uniquely qualified to keep pace with todays concept and product development

LAYERS OF VIRTUAL INSTRUMENTATION SOFTWAREVirtual instrumentation software can be divided into several different layers.1. Application Software: Most people think immediately of the application software layer. This is the primary development environment for building an application. It includes software such as LabVIEW and Measurement Studio (Visual Studio programming languages)2. Test and Data Management Software: Above the application software layer the test executive and data management software layer. This layer of software incorporates all of the functionality developed by the application layer and provides system-wide data management.3. Measurement and Control Services Software: The last layer is often overlooked, yet critical to maintaining software development productivity. The measurement and control services layer includes drivers which communicate with all of the hardware. It must access and preserve the hardware functions and performance. It also must be interoperable it has to work with all other drivers and the many modular I/O types that can be a part of the solution.

Figure 1. Virtual Instrumentation Software

VIRTUAL INSTRUMENTATION FOR TEST Test has been a long-proven field for virtual instrumentation. More than 25,000 companies (the majority being test and measurement companies) use National Instruments virtual instrumentation. Now, companies quickly are adopting up to 200 MS/s digitization capabilities. The PXI consortium hosts more than 60 members delivering hundreds of products. And tens of thousands of R&D, validation, and product test engineers and scientists literally use thousands and thousands of instrument drivers. Still, the need for test has never been greater. As the pace of innovation has increased, so too has the pressure to get new, differentiated products to market quickly. Consumer expectations continue to increase; in electronics markets, for example, disparate function integration is required in a small space and at a low cost. The economic downturn of recent years has not curbed the need to innovate, but instead has added the restraint of fewer resources. Meeting these demands is a factor in business success the company that can meet these demands quickly, consistently, and most reliably has a decided advantage over the competition. All of these conditions drive new validation, verification, and manufacturing test needs. A test platform that can keep pace with this innovation is not optional, it is essential. The platform must include rapid test development tools adaptable enough to be used throughout the product development flow. The need to get products to market quickly and manufacture them efficiently requires high-throughput test. To test the complex multifunction products that consumers demand requires precise, synchronized measurement capabilities. And as companies incorporate innovations to differentiate their products, test systems must quickly adapt to test the new features. Virtual instrumentation is an innovative solution to these challenges. It combines rapid development software and modular, flexible hardware to create user-defined test systems. Virtual instrumentation delivers: Intuitive software tools for rapid test development; Fast, precise modular I/O based on innovative commercial technologies A PC-based platform with integrated synchronization for high accuracy and throughput

VIRTUAL INSTRUMENTATION FOR INDUSTRIAL I/O AND CONTROL

PCs and PLCs both play an important role in control and industrial applications. PCs bring greater software flexibility and capability, while PLCs deliver outstanding ruggedness and reliability. But as control needs become more complex, there is a recognized need to accelerate the capabilities while retaining the ruggedness and reliabilities.

Independent industry experts have recognized the need for tools that can meet the increasing need for more complex, dynamic, adaptive, and algorithm-based control. The PAC is the industrys request and virtual instrumentations answer.

An independent research firm defined programmable automation controllers (PACs) to address the problem. Craig Resnick of ARC Research defines PAC as:1. Multidomain functionality (logic, motion, drives, and process) the concept supports multiple I/O types. Logic, motion, and other function integration is a requirement for increasingly complex control approaches.

2. A single multidiscipline development platform a singular development environment must be capable of supporting varying I/O and control schemes.

3. Software tools for designing applications across several machines or process units the software tools must scale to distributed operation.

4. Open, modular architectures the design and technology specifications must be open, modular, and combinable in implementation

VIRTUAL INSTRUMENTATION FOR DESIGN

The same design engineers that use a wide variety of software design tools must use hardware to test prototypes. Commonly, there is no good interface between the design phase and testing/validation phase, which means that the design usually must go through a completion phase and enter a testing/validation phase. Issues discovered in the testing phase require a design-phase reiteration.

Figure 1. Test plays a critical role in the design and manufacture of todays electronic devices.

In reality, the development process has two very distinct and separate stages design and test are two individual entities. On the design side, EDA tool vendors undergo tremendous pressure to interoperate from the increasing semiconductor design and manufacturing group complexity requirements. Engineers and scientists are demanding the capability to reuse designs from one tool in other tools as products go from schematic design to simulation to physical layout. Similarly, test system development is evolving toward a modular approach. Traditionally, this is the stage where the product designer uses benchtop instruments to sanity-check the physical prototypes against their design for correctness. The designer makes these measurements manually, probing circuits and looking at the signals on instruments for problems or performance limitations. As designs iterate through this build-measure-tweak-rebuild process, the designer needs the same measurements again. In addition, these measurements can be complex requiring frequency, amplitude, and temperature sweeps with data collected and analyzed throughout. Because these engineers focus on design tools, they are reluctant to invest in learning to automate their testing.

TRADITIONAL INSTRUMENT V/S VIRTUAL INSTRUMENT Every virtual instrument consists of two parts software and hardware. A virtual instrument typically has a sticker price comparable to and many times less than a similar traditional instrument for the current measurement task. A traditional instrument provides them with all software and measurement circuitry packaged into a product with a finite list of fixed-functionality using the instrument front panel. A virtual instrument provides all the software and hardware needed to accomplish the measurement or control task. In addition, with a virtual instrument, engineers and scientists can customize the acquisition, analysis, storage, sharing, and presentation functionality using productive, powerful software.

Traditional instruments (left) and software based virtual instruments (right) largely share the same architectural components, but radically different philosophies

CAPABILITIES OF VIRTUAL INSTRUMENTATION HARDWARE An important concept of virtual instrumentation is the strategy that powers the actual virtual instrumentation software and hardware device acceleration. National Instruments focuses on adapting or using high-investment technologies of companies such as Microsoft, Intel, Analog Devices, Xilinx, and others. With software, National Instruments uses the tremendous Microsoft investment in OSs and development tools. For hardware, National Instruments builds on the Analog Devices investment in A/D converters.

Fundamentally, because virtual instrumentation is software-based, if you can digitize it, you can measure it. Therefore, measurement hardware can be viewed on two axes, resolutions (bits) and frequency. Refer to the figure below to see how measurement capabilities of virtual instrumentation hardware compare to traditional instrumentation. The goal for National Instruments is to push the curve out in frequency and resolution and to innovate within the curve.

Figure 1. Compare virtual instrumentation hardware over time to traditional instrumentation. LabVIEW LabVIEW is an integral part of virtual instrumentation because it provides an easy-to-use application development environment designed specifically for engineers and scientists. LabVIEW offers powerful features that make is easy to connect to a wide variety of hardware and other software. This ease of use and these features deliver the required flexibility for a virtual instrumentation software development environment. The result is a user-defined interface and user-defined application functionality.

One of the most powerful features that LabVIEW offers is its graphical programming paradigm. With LabVIEW, engineers and scientists can design custom virtual instruments by creating a graphical user interface on the computer screen through which they: Operate the instrumentation program Control selected hardware Analyze acquired data Display results

They can customize the LabVIEW user interface, or front panel, with knobs, buttons, dials, and graphs to emulate traditional instrument control panels of, create custom test panels, or visually represent process control and operation.

Figure 4. LabVIEW is a leader in application software used in PC-based data acquisition and instrument control.APPLICATIONS

ADVANCED SENSING BIOINFORMATICS GRAPHICAL USER INTERFACES INTERFACING TECHNOLOGIES LOCATION-AWARE TECHNOLOGY MEASUREMENT SYSTEMS MEMS NEXT GENERATION COMPUTING NANOTECHNOLOGY OPTICS RFID ROBOTICS SMART CAMERAS WEB SERVICES WIRELESS COMMS WIRELESS NETWORK SENSORS & SOFTWARE

CONCLUSION Virtual instrumentation is fueled by ever advancing computer technology and it offers the power of creating and defining someones own system based on an open frame work. The combination of computer performance, graphical software, and modular instrumentation has led to the emergence of virtual instruments, which are substantially differ physical ancestors. Virtual instruments are manifested in different forms ranging from graphical instrument panels to complete instrument systems. Modular instrumentation building blocks are becoming more prevalent in the industry and are allowing users to develop capabilities unattainable using traditional instrument architectures. Despite these changes however, these measurement paradigm remains unaltered. This might be the proper platform for the new development.