Labview basic tutorial

VIRTUAL INSTRUMENT (VI)
USING LabVIEW by Amit Verma

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A virtual instrument (VI) has three main
components - the front panel, the block
diagram and the Icon/connector pane.

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THE FRONT PANEL WINDOWS
It is the interactive user
interface for the VI.
It is called front panel
because it stimulates the
front panel of a physical
instrument.
The front panel can
include virtual knobs,
push buttons, graphs
and various other
controls (user input) and
indicators (user output).
Controls are inputs used
to simulate instrument
input device and supply
data to the block
diagram and indicators
are outputs to display
result of simulation.

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THE BLOCK DIAGRAM WINDOWS
It is the
programming
windows.
Block diagram
contains the
graphical source
code composed of
nodes, terminals,
and wires.
Front panel objects
appear as terminal
on the block diagram
and the components
wired together to
form a program.
The data is passed
through the wire

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PALETTES
Palettes are 3 types - Tools, Controls, and Function palettes.

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DATA AND WIRE TYPES

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REPETITION AND LOOPS

For loop - the For loop is
execute until the count
terminal is not equal to one less
than Iteration terminal (i=N-1).

While loop executes a program
till the condition is not met.
There are two condition in while
loop -1) Stop if true, 2)
Continuous If true.

Case Structure - the case
structure execute a subdiagram
for two condition - true and
false . If we want to give two
condition similar as text based
programming language then we
can use it.

Event Structure - The event
structure generate the event
and execute them accordingly.

Formula Node - In the formula
node you can type your formula,
select input/output and use
directly in program.

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Shift Register, Feedback Node and Local Variable
Shift Register - The Shift Register
is used to pass data from current
Iteration to next Iteration till loop
execute.
If we Initialize shift register with
constant 0 then on every
execution loop start with result 0
and no previous execution value
is add the results.
If we doesn't initialize shift
register then on every execution
previous result will be add to
new iteration which is generally
not required by us.
Feedback Node - Like a shift
register, the feedback node is
also used to pass data of current
iteration to next iteration.
Control Timing is used to control
the execution rate of VI.
Local Variable - It transfer data
within a single VI and allow data
to passed between parallel loops.

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ARRAY
The Array can be selected
from
Control>>Modern>>Arrays,
Matrix & Clusters palette.
Insert any Data type to
empty array shell and drag
either horizontally or
vertically.
If you want to Change array
1D to 2D then right click the
left box and select Add
Dimension and further drag.
You can use Array as a
control, Indicator and
constant.
Use Auto Indexing to see
value.
Array follow simple Addition,
Subtraction, Multiplication
and Division rule.
Array is used to store
Multiple data which comes
from each iteration of loop.

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