How to use LabVIEW

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Nov 14, 2013 (3 years and 11 months ago)

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How to use LabVIEW


Ihor Korolov

February 2011

Contents




What is LabVIEW?




How does LabVIEW work?




Block diagram


Front panel


Palettes




Data flow programming. Functions.




LabVIEW Programming Structures (Formula, Case structure …)




What is a subVI? Using a VI as a subVI.




How to use LabVIEW with data acquisition (DAQ) software



Measurements and automation explorer (MAX)



I. Korolov: How to use LabVIEW

What is LabVIEW?

I. Korolov: How to use LabVIEW

LabVIEW



Lab
oratory
V
irtual
I
nstrument
E
ngineering
W
orkbench

is a graphical (visual) programming from National istruments (NI).


The purpose is automating the usage of processing and measuring equipment in any laboratory setup.


Originally released for the Apple Macintosh in 1986, the graphical language at the heart of LabVIEW is called "G".

uses icons instead of lines of text to create programs

Dataflow programming language

C language


Cross
-
platform

The

graphical

approach

of

LabVIEW

allows

non
-
programmers

to

build

programs

by

dragging

and

dropping

virtual

representations

of

lab

equipment

with

which

they

are

already

familiar
.


Price

LabVIEW Professional Development System


I. Korolov: How to use LabVIEW

Desktop PC

Laptop

PDA

http://www.ni.com/labview/buy/

High
-
Speed

Digitizers

High
-
Resolution

Digitizers and DMMs

Multifunction

Data Acquisition

Dynamic

Signal Acquisition

Digital I/O

Instrument

Control

Counter/

Timers

Machine

Vision

Motion

Control

Distributed I/O and

Embedded Control

Laptop PC

PDA

Desktop PC

PXI Modular Instrumentation

Signal Conditioning

and Switching

Unit Under Test

LabVIEW

I. Korolov: How to use LabVIEW

www.ni.com

How does LabVIEW work?

I. Korolov: How to use LabVIEW

How does LabVIEW work?

I. Korolov: How to use LabVIEW

How does LabVIEW work?

I. Korolov: How to use LabVIEW

Front panel

Block Diagram

Ctrl+E

Block diagram toolbar

Reorder objects

Run

Continuous run

Pause

Stop

Debugging features

Clean Up diagram

How does LabVIEW work?

I. Korolov: How to use LabVIEW

LabV
IEW

Front panel

Used to display Controls or Indicators

How does LabVIEW work?

I. Korolov: How to use LabVIEW

LabV
IEW

Block Diagram

-

Actual program

-

Invisible to user

-

Read left to right

Example LP

How does LabVIEW work? Palettes

I. Korolov: How to use LabVIEW

Front panel

Controls palette

Tools palette

Block Diagram

How does LabVIEW work? Tools palette

I. Korolov: How to use LabVIEW

Example

Operating Tool

Positioning/Resizing Tool

Labeling Tool

Wiring Tool

Shortcut Menu Tool


Floating Palette


Used to operate and modify front
panel and block diagram objects.

Scrolling Tool

Breakpoint Tool

Probe Tool

Color Copy Tool

Coloring Tool

Automatic Selection Tool

Data flow programming


I. Korolov: How to use LabVIEW

Data flow programming

I. Korolov: How to use LabVIEW

If

you p
ut
a
control


(or

indicator
)

on the front panel

LabVIEW automatically creates a corresponding

control

(or
indicator
)
terminal

on the
Block
Diagram

Example FP TB

Data flow programming. Functions.


I. Korolov: How to use LabVIEW

View as icon

Click
and
Ctrl+H

“Add” function

wire

Example2,3

Data flow programming. Functions.


I. Korolov: How to use LabVIEW

Example

Data flow programming. Wires


I. Korolov: How to use LabVIEW

Some of basic wires used in block diagrams

Data type

Color

Floating
-
point

orange

Integer

blue

Boolean

green

String

Pink/purple

Dynamic

Dark blue

Broken wires

The wire connects more than one data source

You have connected two terminals of different types

Data flow programming. Functions

I. Korolov: How to use LabVIEW

Example

Data flow programming. Functions

I. Korolov: How to use LabVIEW

Polymorphism

Array Arithmetic Operations

Programming structures


I. Korolov: How to use LabVIEW

LabVIEW Programming Structures

I. Korolov: How to use LabVIEW

For loop

From 0 to N
-
1

Example For Loop

LabVIEW Programming Structures

I. Korolov: How to use LabVIEW

While loop

Repeats the sub diagram inside the loop until
the conditional terminal

receives a particular Boolean value

Auto
-
indexed tunnel

Loop tunnel

Shift register

Timed While loop

Example WhileL

LabVIEW Programming Structures

I. Korolov: How to use LabVIEW

Case structure

Example

LabVIEW Programming Structures

I. Korolov: How to use LabVIEW

Flat sequence structure

Stacked sequence structure

1

2

3

1

2

3

4

Sequence

structures

are

used

to

ensure

a

subdiagram

executes

after

or

before

another

subdiagram

LabVIEW Programming Structures

I. Korolov: How to use LabVIEW

Use global variables to access
and pass data among several
VIs


Use

local

variables

to

read

or

write

to

one

of

the

controls

or

indicators

on

the

front

panel

of

a

VI
.


Local variables

Global variables

Example

LabVIEW: Wait statements

I. Korolov: How to use LabVIEW

Wait Until Next ms Multiple function

Wait (ms) function

Pre
-
loop

code

Loop code

LabVIEW: Graphs

I. Korolov: How to use LabVIEW

Waveform Graph



Plot an array of numbers against their indices

XY Graph



Plot one array against another

Digital Waveform Graph



Plot bits from binary data

Graph properties

Example Graph

LabVIEW: File I/O

I. Korolov: How to use LabVIEW

Write to a File

Read from a File

Writing to LVM file

Reading from LVM file

Write/Read LabVIEW Measurements file

Example File I/O

SubVI

I. Korolov: How to use LabVIEW


What is a subVI? Using a VI as a subVI.

I. Korolov: How to use LabVIEW

What is a subVI?


A SubVi is a stand VI that can be called by other VI and it is similar to an individual function.

Advantages


Modular


Easier to debug


Don’t have to recreate code


Require less memory


What is a subVI? Using a VI as a subVI.

I. Korolov: How to use LabVIEW

How to create a subVI?


A SubVi is a stand VI that can be called by other VI and it is similar to an individual function.



Create/Edit the Icon



Create the Connector



Assign Terminals to controls and indicators



Add description (optional)



Save the VI



Insert the VI into a Top Level VI

1 Create/Edit the Icon

Right
-
click on the icon in

the block diagram or front

panel


What is a subVI? Using a VI as a subVI.

I. Korolov: How to use LabVIEW

2 Create the Connector

Right click on the icon pane (front panel only)

3 Assign Terminals to controls and indicators

r

4 Documentation (VI properties)

5. Save the VI


6. Insert the VI into a Top Level VI

Example

Data acquisition

I. Korolov: How to use LabVIEW

How to use LabVIEW with DAQ software


I. Korolov: How to use LabVIEW


Data acquisition (DAQ)


Connecting Signals


Simple DAQ application

Sensors

Terminal Block

DAQ device

Fundamental task of a DAQ system is to measure or generate real
-
world physical signals

Measurements and automation explorer (MAX)

I. Korolov: How to use LabVIEW

Measurement

&

Automation

Explorer

(MAX)

provides

access

to

all

your

NI

DAQ,

GPIB,

IMAQ,

IVI,

Motion,

VISA,

and

VXI

devices
.

Here

can

configure

your

NI

hardware

and

software,

add

new

channels,

interfaces,

and

virtual

instruments,

execute

system

diagnostics,

and

view

the

devices

and

instruments

connected

to

your

system
.

Configuration tree

Configuration View

Task list

MAX is the primary configuration and testing utility that is available for the DAQ device

MAX

How to use LabVIEW with DAQ software


I. Korolov: How to use LabVIEW

Traditional NI
-
DAQ

Specific VIs for
performing:




Analog Input




Analog Output




Digital I/O




Counter operations

NI
-
DAQmx

Next generation driver:




VIs for performing a


task




One set of VIs for all


measurement types


DAQ assistant

Measurement type can be:



Analog Input



Analog Output



Counter Input



Counter Output



Digital I/O

How to use LabVIEW with DAQ software


I. Korolov: How to use LabVIEW

Ni USB 6501

Quickly and easily program the DAQ device

Creates a local task

Most applications can use the DAQ Assistant

DAQ assistant

Example DAQ

How to use LabVIEW ? Tips and tricks


I. Korolov: How to use LabVIEW




GPIB Communication and Configuration




Virtual Instrument Software Architecture (VISA)


Serial Port Communication




Instrument Drivers (How to create and use *.dll in LabVIEW)




Application control (property node and invoke node)




How to execute a system command




Remote panel connection manager and Web publishing tool








Tips and tricks

(
3
.03.2011)

Köszönöm for your attention!

I. Korolov: How to use LabVIEW