lvb1day2

7/27/2019 Lvb1day2

1/67

LV Basics I 1

Lesson 5Arrays, Graphs, and Clusters

A. About arrays

B. About generating arrays with loops

C. Some basic array functions

D. What polymorphism is

E. Using graphs to display dataF. About clusters

G. Some cluster functions

You Will Learn:

7/27/2019 Lvb1day2

2/67

LV Basics I 2

Arrays

Collection of data elements that are of same type

One or more dimensions, up to 2 elements perdimension

Elements accessed by their index

First element is index 0

31

index

10-element array 1.2 3.2 8.2 8.0 4.8 5.1 6.0 1.0 2.5 1.70 1 2 3 4 5 6 7 8 9

2D array

Five-row by seven columnarray of 35 elements

0 1 2 3 4 5 60

1234

7/27/2019 Lvb1day2

3/67

LV Basics I 3

Array Controls and Indicators

Add Dimension for 2Darrays

1. Select the Array Shellfrom the Controls palette

2. Place data object insideshell

7/27/2019 Lvb1day2

4/67

LV Basics I 4

Creating Array Constants

1. Select ArrayConstant shellfrom the Arraysubpalette

2. Place the data object inthe array shell

7/27/2019 Lvb1day2

5/67

LV Basics I 5

Creating and Using Arrays

Auto- Indexingloops accumulate

arrays at their

boundaries

For Loops auto

index by default;

While Loops do

not

7/27/2019 Lvb1day2

6/67

LV Basics I 6

Creating 2D Arrays

Inner loop creates column elements

Outer loop stacks them into rows

7/27/2019 Lvb1day2

7/67

7/27/2019 Lvb1day2

8/67

LV Basics I 8

The Build Array Function

Building a higher dimension array

Concatenate Inputs (default)

Appending an element

7/27/2019 Lvb1day2

9/67

LV Basics I 9

The Index Array Function

Extracting an Element

Extracting a Row

7/27/2019 Lvb1day2

10/67

LV Basics I 10

Polymorphism

Function inputs can be of different types

All LabVIEW arithmetic functions are polymorphic

Run PolymorphismExample.vi

Scalar + Scalar

Array + Scalar

Combination Result

Scalar

Array

Array

1 4 2

2

4 6 7

5

27

Array + Array 3 2 5

1 4 2

Array + Array 1 4 2

3 2 5 7

Array3 6 4

4 6 7

7/27/2019 Lvb1day2

11/67

LV Basics I 11

Exercise 5-1 on page 5-11

Students buildArray Exercise.viTime to complete : 20 min.

7/27/2019 Lvb1day2

12/67

LV Basics I 12

Graphs

Selected from the Graph subpalette

Waveform Graph Plot an array of numbersagainst their indices

XY Graph Plot one array against another

Plot Legend(point and

line styles)

Graph PaletteScale Legend

7/27/2019 Lvb1day2

13/67

LV Basics I 13

Single-Plot Waveform Graphs

Uniform X axis - initial X = 0.0, delta X = 1.0

Uniform X axis - you specify point spacing

7/27/2019 Lvb1day2

14/67

LV Basics I 14

Multiple-Plot Waveform Graphs

Each row is a separate plot (initial X = 0, delta X = 1)

Each row is a separate plot (Bundle specifies point spacing

of the X axis)

7/27/2019 Lvb1day2

15/67

LV Basics I 15

XY Graphs

Non-uniformX axis

Separate X

and Y arrays

define datapoints

7/27/2019 Lvb1day2

16/67

LV Basics I 16


Students buildGraph Waveform Array.viTime to complete : 30 min.

7/27/2019 Lvb1day2

17/67

LV Basics I 17


Students buildTemperature Analysis.vi*This VI will be used in a later exercise.

Time to complete: 25-30 min.

7/27/2019 Lvb1day2

18/67

LV Basics I 18

Exercise 5-4 on page 5-26 (Optional)

Students buildGraph Circle.viTime to complete : 20 min.

7/27/2019 Lvb1day2

19/67

LV Basics I 19

Chart and Graph Use Summary

Use the Context Help window with charts and graphs

7/27/2019 Lvb1day2

20/67

7/27/2019 Lvb1day2

21/67

LV Basics I 21

1. Select a Clustershellfrom the Array &Clustersubpalette

Cluster Controls and Indicators

2. Place objects inside the shell

7/27/2019 Lvb1day2

22/67

LV Basics I 22

Cluster Constants

Select a ClusterConstant shell from the Cluster

subpalette Right-click on existing cluster and select

Create>>Constant

7/27/2019 Lvb1day2

23/67

7/27/2019 Lvb1day2

24/67

LV Basics I 24

Use Clusters to Pass Data to SubVIs

Use clusters topass several

values to one

terminal

Overcomes 28-terminal limit

Simplifies wiring

7/27/2019 Lvb1day2

25/67

LV Basics I 25

Cluster Functions

In the Clustersubpalette of the Functions palette

Can also be accessed by right-clicking on the clusterterminal

Bundle

(Terminal labelsreflect data type)

Bundle By Name

7/27/2019 Lvb1day2

26/67

LV Basics I 26

Cluster Functions

Unbundle

Unbundle By Name

Unbundled clusterin the diagram

7/27/2019 Lvb1day2

27/67

LV Basics I 28

Polymorphism with Clusters

Polymorphic functions work with clusters

Arithmetic functions can perform computationson clusters of numeric data

7/27/2019 Lvb1day2

28/67

LV Basics I 29

Exercise 5-5 on Page 5-40

Students build Cluster Exercise.viApproximate time to complete: 30 min.

7/27/2019 Lvb1day2

29/67

LV Basics I 30

Exercise 5-6 on Page 6-43

(Optional)

Students build Cluster Scaling.viApproximate time to complete: 10 min.

7/27/2019 Lvb1day2

30/67

LV Basics I 31

Summary

An array is a collection of elements of same data type

numeric, Boolean, string, etc. Creating array or cluster controls/indicators is a two-step

process 1. Get array or cluster shell2. Place desired control/indicator inside the shell

Loops can accumulate arrays at boundaries auto-indexing

Array functions are in Array subpalette of Functions palette

LabVIEW arithmetic functions are polymorphic inputdifferent data types

Plot data on graphs

Many features to manipulate plotted graph

Multiple plots can be plotted on one graph

Clusters group data that can be different types

The Bundle and Unbundle functions are used to create anddisassemble clusters

7/27/2019 Lvb1day2

31/67

LV Basics I 32

Additional Exerciseson page 5-46

5-7Students buildReverse Random Array.viTime to complete: 20 min.

5-8Students buildFind Mid Value.viTime to complete: 20 min.

5-9Students buildExtract 2D Array.viTime to complete: 20 min.

5-10 (Challenge) Students buildDie Roller.viTime to complete: 35-40 min.

5-11 (Challenge) Students build Array Pair Multiplier.viTime to complete: 20 min.

7/27/2019 Lvb1day2

32/67

LV Basics I 33

Lesson 6Case and Sequence Structures

A. About Case structuresB. About Sequence structures

C. About Formula Nodes

D. How to replace Sequence structures

You Will Learn:

7/27/2019 Lvb1day2

33/67

LV Basics I 34

Case Structures

In the Structures subpalette of Functions palette

Enclose nodes or drag them inside the structure Stacked like a deck of cards, only one case visible

7/27/2019 Lvb1day2

34/67

LV Basics I 35

Boolean and Numeric Cases

Note: all possible outputs of the Case structure must be wired

7/27/2019 Lvb1day2

35/67

7/27/2019 Lvb1day2

36/67

7/27/2019 Lvb1day2

37/67

LV Basics I 38

Sequence Structures

In the Structures subpalette of Functions palette

Executes diagrams sequentially, Frame 0 (0..x),where x is the total number of frames

Stacked like a deck of cards, only one frame visible

7/27/2019 Lvb1day2

38/67

LV Basics I 39

Sequence Locals

Pass data from one frame to future frames

Created at the border of the Sequence structure

Sequence localcreated inFrame 1

Data notavailable

Dataavailable

7/27/2019 Lvb1day2

39/67

LV Basics I 40


Students buildTime to Match.vi by modifyingAuto Match.vi (Ex. 4-3)Time to complete: 30 min.

7/27/2019 Lvb1day2

40/67

LV Basics I 41

Formula Node

In the Structures subpalette Implement complicated equations

Variables created at border

Variable names are case sensitive

Each statement must terminate with a semicolon (;)

Context Help Window shows available functions

Note semicolon

7/27/2019 Lvb1day2

41/67

LV Basics I 42

Conditional Branching in Formula Nodes

if (x >= 0) then

y = sqrt(x)else

y = -99999.0end if

Condition

Conditional Operator

True Condition

False Condition

7/27/2019 Lvb1day2

42/67

LV Basics I 43


Students buildFormula Node Exercise.viTime to complete: 20 min.

7/27/2019 Lvb1day2

43/67

7/27/2019 Lvb1day2

44/67

LV Basics I 45

Summary

Two structures to control flow of data

Case structure Sequence structure

Case structure

Boolean or numeric cases selector determines type

Subdiagrams placed inside case structure

Output from a Case structure must be defined for all cases Sequence structure executes subdiagrams sequentially

Sequence locals pass data between frames

Created at the border of Sequence structure

Data available in subsequent frames

Formula Nodes allow direct entry of equations in the blockdiagram

Sequence structures can be replaced with a Case inside of a

Loop

7/27/2019 Lvb1day2

45/67

LV Basics I 46

Additional Exercises on page 6-23

6-5 Students buildEquations.viTime to complete: 20 min.

6-6 Students buildCalculator.viTime to complete: 30 min.

6-7 Students buildSquare Root 2.viTime to complete: 20 min.

6-8

(Challenge) Students buildUsing ArrayOver Threshold.vi

Time to complete: 30 min.

7/27/2019 Lvb1day2

46/67

LV Basics I 47

Lesson 7Strings and File I/O

A. How to create string controls and

indicatorsB. Some string functions

C. How to perform file input and output

operations

D. How to format text files for spreadsheets

E. How to use the high-level File VIs

You Will Learn:

7/27/2019 Lvb1day2

47/67

7/27/2019 Lvb1day2

48/67

LV Basics I 49

String Display Modes

Normal display

Password display

\ code display

Hex display

7/27/2019 Lvb1day2

49/67

LV Basics I 50

String Functions

Concatenate Strings

The quick brown fox jumped over the lazy dog.

Concatenated String

Strings

spaces here

String Length

= 20Length

String

7/27/2019 Lvb1day2

50/67

LV Basics I 51

String Functions

7/27/2019 Lvb1day2

51/67

LV Basics I 52

String Functions

Converting numbers to strings

Converting strings to numbers

7/27/2019 Lvb1day2

52/67

LV Basics I 53

Edit Format StringFormat Into String & Scan From String Functions

7/27/2019 Lvb1day2

53/67

7/27/2019 Lvb1day2

54/67

LV Basics I 55

File Input and Output

Three levels of hierarchy

High-level utility file VIs

Intermediate file I/O VIs

Advanced file I/O functions

High Level File VIs

Intermediate FileVIs and Functions

Advanced FileFunctions

7/27/2019 Lvb1day2

55/67

LV Basics I 56

Intermediate File I/O VIs

Open/Create/Replace file opens, creates, or

replaces a file

Read File reads count bytes from the file

Write File writes data to the file

Close File closes the file

Error handling in file I/O Time & Dialog subpalette

Displays a dialog box if an error occurs

7/27/2019 Lvb1day2

56/67

LV Basics I 57

Saving Data to a File

Open/Create/Replace opens the existing fileTEST1.DAT and generates refnum and error

cluster

Write File writes the data


Simple Error Handler checks for errors

7/27/2019 Lvb1day2

57/67

LV Basics I 58

Reading Data from a File

Open/Create/Replace opens the file

Read File reads the specified number of bytesfrom the file


Simple Error Handler checks for errors

7/27/2019 Lvb1day2

58/67

LV Basics I 59


Students buildFile Writer.viTime to complete: 20 min.

7/27/2019 Lvb1day2

59/67

LV Basics I 60


Students buildFile Reader.viTime to complete: 20 min.

7/27/2019 Lvb1day2

60/67

LV Basics I 61

Formatting a Spreadsheet String

Spreadsheets are popular tools for data handling

and analysis There are many formats for spreadsheet data.

One of the most popular is tab-del imited:

Columns are separated by a tab character

Rows are separated by an end-of-linecharacter

Easily created using LabVIEW file I/O VIs

7/27/2019 Lvb1day2

61/67

7/27/2019 Lvb1day2

62/67

LV Basics I 63


Students buildTemperature Logger.vi bymodifying Temperature Control.vi

*This VI will be used in a later exercise.Time to complete: 25 min.

7/27/2019 Lvb1day2

63/67

LV Basics I 64

High-level File I/O VIs

Write to Spreadsheet File

Read from Spreadsheet File Write Characters to File

Read Characters from File

Read Lines from File

7/27/2019 Lvb1day2

64/67

LV Basics I 65


Students runSpreadsheet Example.viTime to complete: 25 min.

7/27/2019 Lvb1day2

65/67

S

7/27/2019 Lvb1day2

66/67

LV Basics I 67

Summary

String is a collection of ASCII characters many uses

Display messages

Instrument control

File I/O

Many functions to manipulate strings Strings palette of

Functions menu

Three levels of File I/O hierarchy

High-level VIs

Intermediate VIs and functions

Advanced functions

Writing data in spreadsheet format Tab character separates columns

End-of-line character separates rows

Write/Read from spreadsheet high-level File I/O VIs

7/27/2019 Lvb1day2

67/67

Additional Exercises on page 7-37

7-7(Challenge)Students build MoreSpreadsheets.vi


7-8

(Challenge)Students buildSpreadsheetConverter.vi


7-9

Students modifyTemperature Logger.vi(Ex. 7-4) and save the new VI asTemperature Logger 2.vi


lvb1day2

Documents