introducwon to labview

Introduc)on to LabVIEW

Hans-‐Pe6er Halvorsen, M.Sc.

Basic LabVIEW Programming

Na#onal Instruments is the vendor of LabVIEW

Na)onal Instruments creates both Hardware and So3ware

LabVIEW = Fun! Graphical Programming: •  Very different from tradi)onal programming like

VB, C#, Maple, MATLAB, MathScript, etc. •  It is more like a “drawing program” than a

Programming Language •  This makes it easy to use for those who are not

programmers (or dont like programming J) •  Excellent tool when using Hardware, when you

need to take Measurements (DAQ), etc. •  It is fun and makes you very crea)ve!

LabVIEW Example

Property Nodes

Sequence Structure While Loop Sub VI

Case Structure Constants

Arrays

Stop Bu6on

Condi)on (When the loop shall end)

Local Variable Comment

Note! To do something with an object – Right-‐click on it

Hardware

cRIO

ZigBee

Vision System

Arduino

USB-‐6008

Wi-‐Fi DAQ

TC-‐01

NOx Sensor

Pt-‐100

Air Heater

Water Tank

LabVIEW Installa)on Download the sodware here: h6ps://lumen.ni.com/nicif/us/acadevallvdl/content.xhtml These are the main modules we use in the different courses at Telemark University College: •  LabVIEW (LabVIEW Professional Development System 32-‐Bit: English) •  LabVIEW MathScript RT Module •  LabVIEW Control Design and Simula#on Module •  LabVIEW PID and Fuzzy Logic Toolkit •  LabVIEW System Iden#fica#on Toolkit •  NI-‐DAQmx (Hardware Driver) Note! These packages are separate downloads! Make sure to download and install all of them! Select the Sodware in the “August 2013” column (LabVIEW 2013).

Note! The Serial Number is in Fronter!

LabVIEW Training

•  LabVIEW Training for Students (Na)onal Instruments):

h6p://www.ni.com/academic/students/learn-‐labview/

•  LabVIEW Course: h6p://home.hit.no/~hansha/?training=labview

LabVIEW Environment

Select File -‐> New VI (Ctrl + N) in order to start using LabVIEW

Students: Try this

This window appears when you start LabVIEW:

LabVIEW Environment Front Panel

Block Diagram

Create your User Interface/HMI here

Create your Code here

Switch between them: Ctrl + E

Students: Try this

Note! Both the Front Panel and the Block Diagram is stored in one single file. These files are called VIs (because the file extension is “.vi”). VI = Virtual Instruments

Controls and Func#ons Pale6e

Available from the Front Panel

Available from the Block Diagram

You create your User Interface Yo

u create you

r Cod

e

Right-‐click on the Front Panel

Right-‐click on

the Block Diagram

Students: Try this

You can “pin” them!

Customizing Controls and Func)ons Pale6es

Students: Do this for both the Controls PaleVe and the Func#ons PaleVe

Customizing LabVIEW IDE Select Tools ! Op#ons…

Students: Change the different op)ons according to how you want to use LabVIEW

Simple Example

Students: Try this simple example. Try “Minus”, “Divide” and “Mul)ply” as well.

Run the Program

Find these Controls and Indicators in the Controls Pale6e and place them on the Front Panel

Connect these together using the “Wiring tool” (your mouse)

Front Panel

Block Diagram

Controls Indicator

Controls vs.

Indicators

What is the difference?

Another Example Celcius to Fahrenheit

Students: Create the Front Panel and Block Diagram above

Front Panel

Block Diagram

Ctrl + B

While Loop

Students: Create this Example

While Loop

Block Diagram

Front Panel

Front Panel: Find these Controls in the Controls Pale6e and place them on the Front Panel with proper labels

Block Diagram: Find the While Loop in the Func)ons Pale6e and place it on the Block Diagram

Block Diagram: Connect these together using the “Wiring tool” (your mouse)

Run the Program

Purpose: A voltage signal [0-‐5V] from a DAQ device needs to be converted to the equivalent level values in a water tank [0-‐20cm]


Plopng

Students: •  Create this VI •  Try out different op)ons on the Chart,

e.g. Autoscale, different Modes, Layout, Colors, etc. (Right-‐click on the Chart)

Purpose: This example simulates the Temperature in the Air Heater. The Temperature in the Air Heater should be between 20 and 50 degrees Celsius. We use the Random Generator in LabVIEW


Charts vs. Graphs Chart: •  Remembers history – New point added to end of plot

•  Used inside a While Loop •  One new point is added each )me Graph: •  You plot all the data at once – typically an array with data

•  Used outside a While Loop

Charts vs. Graphs -‐ Example

Students: Create this VI in order to see the difference between a Chart and a Graph


Right-‐click on the border

SubVIs Input Output

(Control) (Indicator)

Icon that makes it easier to understand what the SubVI is doing

A SubVI is the same as a func)on or a method used in other languages

Students: Create this VI

Select Inputs and Outputs

Using SubVIs

SubVI (just drag it on the Block Diagram with your mouse)

Students: Create this VI

Project Explorer Similar to “Solu)ons Explorer” in Visual Studio. Keeps all your Files for a spesific project in one place.

It is recommended to use this when you create larger applica)ons that contains lots of VIs and other files, etc.

I need Help!! Ctrl + H When you use Ctrl + H, you may click on all kind of objects (both on Front Panel and Block Diagram) on the screen to get help, e.g., built-‐in func)ons

Ctrl + H

Spaghep Code – Bad Example1

Structure your code! Use SubVIs, Avoid Spaghep Code, Document your Code, etc.

Spaghep Code – Bad Example2

Structure your code! Use SubVIs, Avoid Spaghep Code, Document your Code, etc.

Make sure your code fits into your screen size – scrolling to see code is not good!

Good vs. Bad Code

Use SubVIs!!!

Avoid Spaghe[ Code!

The Flow should go from le3 to right

Make your code readable for others!

Short-‐Cuts

•  There are no Short-‐Cuts if you want to learn LabVIEW! (except the few shown on the previous page J)

•  Prac)ce, prac)ce and prac)ce!

LabVIEW Training: 1 -‐ LabVIEW Training for Students (Na)onal Instruments):

h6p://www.ni.com/academic/students/learn-‐labview/ 2 -‐ LabVIEW Course: h6p://home.hit.no/~hansha/?training=labview

Sorry!

Hans-‐PeVer Halvorsen, M.Sc. Telemark University College Faculty of Technology Department of Electrical Engineering, Informa#on Technology and Cyberne#cs

E-‐mail: [email protected] Blog: hVp://home.hit.no/~hansha/

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