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In system specification software requirement and virtual instrumentation are included.
Lab VIEW is the software requirement its significances are also included. In addition to this
importance of virtual instrumentation are discussed.
SOFTWARE REQUIREMENT
Lab VIEW is a fully featured programming language produced by National Instruments.
It is graphical language quite unique in the method by which code is constructed and saved.
There text based code as such, but a diagrammatic view of how the data flows through the
program. Thus Lab VIEW is a much loved tool of the scientist and engineer who can often
Visualize data flow rather than how a text based conventional programming language must be
Built to achieve a task Lab VIEW programs are called virtual instruments, or Vis, because their
appearance and Operation imitates physical instruments, such as oscilloscopes and millimetres.
Lab VIEW contains a comprehensive set of tools for acquiring analyzing, displaying, and storing
data, as well as tools to help you troubleshoot your code. Lab VIEW Vis contains three
components – the front panel, the block diagram, and the icon and connector pane. In Lab
VIEW, you build a user interface, or front panel, with controls and indicators. Controls are knobs
push buttons, dials, and other input devices. Indicators are graphs, LEDs, and other displays.
After building the user interface, code is added using VIs and structures to control the front panel
objects. The block diagram contains this code. In some ways, the block diagram resembles a
flowchart. Lab VIEW is used to communicate with hardware such as data acquisition, vision,
and motion control devices and GPIB, PXI, VXI, RS-232, and RS-484 devices. Lab VIEW also
has built-in features for connecting your application to the Web using the Lab VIEW Web Server
and Software standards such as TCP/IP networking and ActiveX. Using Lab VIEW test and
measurement, data acquisitions, instrument control, data logging, measurement analysis, and
report generation applications.
VIRTUAL INSTRUMENTATION
Virtual Instrumentation is the use of customizable software and modular measurement
hardware to create user-defined measurement systems, called virtual instruments. ‘Traditional’ or
‘natural’ instrumentation systems are made up of pre-defined hardware components, such as
digital millimeters and oscilloscopes that are completely specific to their stimulus, analysis, or
measurement function. Because of their hard-coded function, these systems are more limited in
their versatility than virtual instrumentation systems. The primary difference between ‘natural’
‘instrumentation and virtual instrumentation’ is the software component of a virtual instrument.
The software enables complex and expensive equipment to be replaced by simpler and less
expensive hardware; e.g. analog to digital converter can act as a hardware complement of a
virtual oscilloscope, a potentiostat enables frequency response acquisition and analysis in
electrochemical impedance spectroscopy with virtual instrumentation. The concept of synthetic
instrument is a subset of the virtual instrument concept. A synthetic instrument performs a
specific synthesis, analysis, or measurement function on completely generic, measurement
agnostic hardware. Virtual instruments can still have measurement specificity. Hardware
supporting synthetic instruments is by definition not specific to the measurement, nor is it
necessarily (or usually) modular.
CONCEPTS IN LAB VIEW:
The rapid adoption of the PC in the last 20 years catalyzed a revolution in
instrumentation for test, measurement, and automation. One major development resulting from
the ubiquity of the PC is the concept of virtual instrumentation, which offers several benefits to
engineers and scientists who require increased productivity, accuracy and performance.
A virtual instrument consists of an industry-standard computer or workstation equipped
with powerful application software, cost-effective hardware such as plug-in boards, and driver
software, which together perform the functions of traditional instruments. Virtual instruments
represent a fundamental shift from traditional hardware-centered computing power, productivity,
display, and connectivity capabilities of popular desktop computers and workstations. Although
the PC and integrated circuit technology have experienced significant advances in the last two
decades, it is software that truly provides the leverage to build on this powerful hardware
foundation to create virtual instruments, providing better was to innovate and significantly
reduce cost.
With virtual instruments, engineers and scientists build measurement and automation
systems that suit their needs exactly(user-defined) instead of being limited by traditional fixedfunction
instruments(vendor-defined).
Leading vendor National Instruments defines virtual instrumentation, as “a layer of
software and/or hardware added to a general-purpose computer in such a fashion that users could
interact with the computer as though it were their own custom-designed traditional electronic
instrument”. Virtual comes from the Latin virtus, which means “potential” or “force”, and
becomes actual once it is made effective, perceptible or operative.
LabVIEW is an integral part of virtual instrumentation because it provides an easy-to-use
application development environment designed specifically with the needs of engineers and
scientists in mind. LabVIEW offers powerful features that make is easy to connect to a wide
variety of hardware and other software.
One of the most powerful features that LabVIEW offers engineers and scientists is its
graphical programming environment. With LabVIEW can design custom virtual instruments by
creating a graphical user interface on the computer screen through the following steps.
Operate the instrumentation program
Control selected hardware
Analyze acquired data
Display results
Graphical programming system for data acquisition and control, data analysis and data
presentation offers a new programming methodology how graphically assembles software
objects called virtual instruments (VIs). Virtual Instrumentation tools are used also for research
work at the Department of Electrical Measurement.
INTRODUCTION TO LABVIEW:
LabVIEW is a development environment based on graphical programming. LabVIEW
uses terminology. Icons and ideas familiar to technicians, scientists, engineers and relies on
graphical symbols rather than technical language to describe programming actions.
LabVIEW is a graphical programming language that uses icons instead of lines of text to
create application, in contrast to text-based programming language, where instructions determine
program execution. LabVIEW uses dataflow programming.
In LabVIEW, there is a user interface by using a set of tools and objects. The user
interface is known as the front panel. The code is added using graphical representation of
function to control the front panel objects.
LabVIEW is integrated fully for communication with between such as GPIB, PXI, RS-
232, RS-485 and plug-in data acquisition devices. LabVIEW also has built-infeatures for
connecting out application to the internet using LabVIEW also has built-in feature for connecting
out application to the internet using LabVIEW web server and software standards such as
TCP/IP networking and active.
Using LabVIEW, 32-bit compiled applications that give past execution speeds needed for
custom data acquisition, test measurement and control solutions can be created.
Using LabVIEW stand-alone executables and shared libraries, like Dills, because
LabVIEW is a true 32-bit compiler can be created.
LabVIEW contains comprehensive libraries for data collection, analysis, presentation and
storage. LabVIEW also includes traditional program execution and single-step can be set up
through the program to make debugging and development easier.
LabVIEW also provides numerous mechanisms for connecting to external code or
software through DLLs, shared libraries, active and more.