Transcript ECE 437: Lecture 1

Introduction to LabVIEW 8.5
• Original slides prepared by Prof. Xiaobin Le of
Mechanical Engineering program
• Adapted for Electrical Mechanical Engineering
program by Cap’n Tim Johnson, PE
Introduction to LabVIEW
Introduction to LabVIEW (1)
• What is LabVIEW?
– LabVIEW
– The Virtual Instrumentation (VI) Approach for
measurement systems
• LabVIEW environment
– Three parts of a VI
– Three palettes
– Show context help
– Status bar
What is LabVIEW?
• LabVIEW - Laboratory Virtual Instrument
Engineering Workbench
• LabVIEW is a software, which uses
graphical programming language for data
acquisition, data analysis, presentation of
result and instrument control.
• LabVIEW program is called virtual instrument
(VI), because their appearance and operation
imitate physical instruments, such as
oscilloscopes and multimeters
The VI approach for measurement systems
LabVIEW
+
Computer
PXI Modular Instrumentation
High-Speed High-Resolution
Multifunction
Dynamic
Instrument
Digitizers and DMMs Data Acquisition Signal Acquisition Control
Digitizers
Signal Conditioning
and Switching
Unit Under Test
Laptop PC
Desktop PC
Digital I/O
Counter/
Timers
Machine
Vision
Motion
Control
Distributed I/O and
Embedded Control
Hardware + sensor
Object being tested
PDA
LabVIEW environment
• LabVIEW provides an easy-to- •
use graphical programming
environment, including all of
the tools necessary for data
acquisition (DAQ), data
analysis and presentation of
results.
•
• LabVIEW tries to make your
life as hassle-free as possible.
It has extensive libraries of
functions and subroutines to
•
help you with most
programming tasks.
•
Three parts of a VI
– Front panel
– Block diagram
– Icon and connector
pane
Three palettes
– Tools palette
– The Controls palette
– The Functions palette
Show context Help
Status bar
Three parts of a VI
A VI contains the following three components:
– Front panel—Serves as the user interface for input
and show results for output and presentation.
– Block diagram—Contains the graphical source
code that defines the functionality of the VI. (It is a
executable program.). It is similar to circuits
– Icon and connector pane—Identifies the VI so that
you can use the VI in another VI. Actually every
graphic icon is a kind of sub-VI. It can execute a
simple or complicated task and with input and
output terminals.
Front Panel
• The front panel is the user interface of the VI.
– A front panel contains controls for input and
indicators for output or data presentation
• Controls are knobs, pushbuttons, dials, and
other input devices.
– Controls simulate instrument input devices and
supply data to the block diagram of the VI.
• Indicators are graphs, LEDs, and other displays.
– Indicators simulate instrument output devices and
display data the block diagram acquires or
generates.
A VI’s Front Panel
Front Panel
• Controls = Inputs
• Indicators = Outputs
Front Panel
Toolbar
Boolean
Control
Icon
Graph
Legend
Waveform
Graph
Plot
Legend
Scale
Legend
Block diagram
– A virtual circuit in which virtual components
are wired together
– A executable graphical program
– Accompanying “program” for front panel
A VI’s Block Diagram
Block
Diagram
Toolbar
Divide
Function
SubVI
Graph
Terminal
Wire
Data
While Loop
Structure
Numeric
Constant
Timing
Function
Boolean Control
Terminal
Icon and connector pane
– Icon and connector pane—Identifies the VI
so that you can use the VI in another VI. A VI
within another VI is called a sub-VI.
– Provide the connectors for wiring
Three LabVIEW Palettes
• The Tools palette is available on the front
panel and the block diagram.
– A tool is a special operating mode of the
mouse cursor.
• The Controls palette is available only on the
front panel.
– The Controls palette contains the controls
and indicators you use to create the front
panel.
• The Functions palette is available only on the
block diagram.
– The Functions palette contains the VIs and
functions you use to build the block diagram.
Tools Palette
•The Tools palette is available on the front panel and the
block diagram.
•A tool is a special operating mode of the mouse cursor.
•Select View»Show Tools Palette to display the Tools
palette.
• Floating Palette
• Used to operate and modify front panel and
block diagram objects.
Automatic Selection Tool
Operating Tool
Scrolling Tool
Positioning/Resizing Tool
Breakpoint Tool
Labeling Tool
Probe Tool
Wiring Tool
Color Copy Tool
Shortcut Menu Tool
Coloring Tool
The Controls palette
• Select View»Show Controls Palette or right-click the
front panel workspace to display the Controls palette
• In the front panel mode, right click any empty place,
the “control palette” will be shown. After you choose
proper screen, you can pin that screen.
Functions Palette
•Select View»Show Functions Palette or right-click the block
diagram workspace to display the Functions palette.
•In the Block diagram mode, right click any empty place, the
“function palette” will be shown. After you choose proper screen,
you can pin that screen.
Show context Help
When you point at any icon (graphical code), the
description of the icon will be shown if the “show context
help” is checked.
Status Toolbar
Run Button
Continuous Run Button
Abort Execution
Additional Buttons on
the Diagram Toolbar
Execution Highlighting Button
Retain Wire Values Button
Step Function Buttons
End of Overview
• The next few slides will help you get
started making your own virtual
instrument.
Open LabVIEW
Lab #1 instructions
• Read Ch1 in “Getting Started with LabVIEW.
• If your instructor hands out the pages for this chapter you won’t
need to open up the manual (instructions follow)
• This manual is found (on my machine) at C:\Program Files\National
Instruments\LabVIEW 8.2\manuals or 2 selections down from where
you clicked to start LabView.
• Click on LV_Getting_Started.pdf to open the manual.
• Do NOT print out the manual!!!!
• If you are working as a team have one of your team mates open up
the PDF and use that as your copy.
• You can also as a supplement use two video tutorials found in the
Start menu called:
to to enhance your understanding.
Tutorial
• As you read through the chapter make the
VI and modifications suggested.
• Design a cover page for this lab that
includes your name, course, Lab # and
name, date, and a brief abstract.
• Turn in a screen print of the design’s front
panel and block diagram.
• Answer the questions on the following
page.
Begin designing
• You are on your way.
• This lab is part of the design process steps
Gathering Information and
Conceptualizing Alternate Solutions.
• The questions you are answering are:
What role will this software fulfill in a
system?
What does using this software add to a
system?
Homework Assignment #1
• Before the class meets again for lab…
• Read Ch2 in “Getting Started with
LabVIEW”. Follow along in their tutorial
and make the design suggested in the
chapter.
• Submit a copy of the design including the
Front Panel and the Block Diagram.
• Include a write up about how the design
works and what problems it can solve.