1. LabVIEW Course
Course 2

2. Analyzing and saving data
Course Map
Course 1
Course 2
Course 3
Making a decision
First steps
with LabVIEW
Controlling property
Loops
Creation of new VI
and customization
Arrays
Project
Signal generation
Modular
programming
Saving data
Analyzing and saving data
Data acquisition
Express VI
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3. Lesson 5 Make a decision TOPICS Function select Case Structures
Formula Nodes
Boolean and text format
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4. Datas take the specific road if decision
Function “Select”
Input for right
decision
output
Input for false
Datas take the specific road if decision
« Right »
« False »
Input for right
right
false
output
output
Input for false
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5. Case Structures Boolean Case Structure Example:
If Temp Scale is TRUE, execute True case; if temp scale is FALSE, execute False case.
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 at a time
The Case structure allows you to choose a course of action
depending on an input value.
In the Structures subpalette of the Controls palette.
Analogous to a case statement in Pascal or if-then-else statement in other languages.
Like a deck of cards. You can see only one case at a time.
Customers often think that when separate cases are shown, it means to create two or more case structures. Stress that you need only one case structure. (See next slide for example of this idea.)
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6. Create a Case Structures (1/3)
Select the case structure into the Function Palette
Insert the structure into D
Link data input/output to borderline
of the case structure
The Case structure allows you to choose a course of action
depending on an input value.
In the Structures subpalette of the Controls palette.
Analogous to a case statement in Pascal or if-then-else statement in other languages.
Like a deck of cards. You can see only one case at a time.
Customers often think that when separate cases are shown, it means to create two or more case structures. Stress that you need only one case structure. (See next slide for example of this idea.)
Each output must be connected
in every case of the case structure
Output connector : white
=> 1 case connector not linked
(here the false one)

7. Create a Case Structures (2/3)
Link every output connector
The Case structure allows you to choose a course of action
depending on an input value.
In the Structures subpalette of the Controls palette.
Analogous to a case statement in Pascal or if-then-else statement in other languages.
Like a deck of cards. You can see only one case at a time.
Customers often think that when separate cases are shown, it means to create two or more case structures. Stress that you need only one case structure. (See next slide for example of this idea.)

8. Create a Case Structures (3/3)
Create the boolean condition
The Case structure allows you to choose a course of action
depending on an input value.
In the Structures subpalette of the Controls palette.
Analogous to a case statement in Pascal or if-then-else statement in other languages.
Like a deck of cards. You can see only one case at a time.
Customers often think that when separate cases are shown, it means to create two or more case structures. Stress that you need only one case structure. (See next slide for example of this idea.)

9. Exercise 5.1 – User choice Goal Concepts Homework Create a simple VI
Topic : display the generated temperature in the specific scale selected by user
Concepts
Make a decision with the “select function” and “case structure”
Boolean, text and numeric formats
Homework
Open Gen_temp_conv.vi
Step 1 : create a program to allow user to choose and select the unit of the generated temperature and display it in only one indicator. (using the select function)
Step 2 : With the same method, display the unit (in text format) in another indicator. Save in “Gen_Simple_Choice.vi”
Step 3 : replace the 2 functions “select” by only 1 case structure. Save as “Gen_case.vi”
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10. Exercise 5.1 – D solution with select function
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11. Exercise 5.1 – D solution with case structure
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12. Exercise 5.1 – FP
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13. Note
As you can notice, when you change the unit, the thermometer scale is not necessarily well adapted. The ideal would be a scale which would change according to the unit chosen.
In order to achieve this, you have to work on the intrinsic properties of the indicator.
This requires the use of "property nodes"…
Estimate completion time: 20 minutes. The exercise is easy, but since it will be the first VI that we actually create, it is good to allow ample time to explore the LabVIEW environment.
Instructions: Build a VI that converts °C to °F. When run, the VI should take an input value (°C), multiply it by 1.8, add 32, and display the result (°F). The front panel should display both the input value and the result. Save the VI as Convert C to F.vi.
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14. Lesson 6 How to control properties of objects by programming
TOPICS
Property nodes
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15. What is a property node ?
Each objects that you use in Labview owns its intrinsic properties. It can be the "visibility", the "state" (active or not active), or for indicators the "scale"…
Working on these properties inside a program lead to the use of "property nodes" allowing to edit or modify these different properties.
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16. How to create it ?
Right click on the indicator
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17. How to modify it ?
As default value the property is the visibility, but you can change it by right clicking on the property node and choosing another property.
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18. How to add another property node ?
You can create another property node by the same method, however a more simple solution exists. Indeed, once a property node has been created, you just have to pull down, and others property nodes are added…
Pull down
Property nodes automatically added
If you want to change the properties added, you just have to refer the previous step.
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19. Exercise 6.1 Goal Topics Homework
Adjust the scale of temperature indicators by programmation
Topics
Use of property node
Customization of user interface
Homework
Open “Gen_case.vi "
Use property nodes to automatically adjust the scale of the temperature indicator according to the unit chosen.
Save as “Gen_case_adjusted.vi"
Estimate completion time: 20 minutes. The exercise is easy, but since it will be the first VI that we actually create, it is good to allow ample time to explore the LabVIEW environment.
Instructions: Build a VI that converts °C to °F. When run, the VI should take an input value (°C), multiply it by 1.8, add 32, and display the result (°F). The front panel should display both the input value and the result. Save the VI as Convert C to F.vi.
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20. Exercise 6.1 - D °F : min = 0 max = 200 °K : min = 100 max = 300
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21. Exercise FP
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22. Lesson 7 Repetition and Loops
TOPICS
While Loops
For Loops
Accessing Previous Loop Data
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23. Structures and Loops
Sequence
While
For
Case
Formula node

24. Sequence Structure Execute the program in a specific order
Dans les langages de base, le programme s’exécute dans l’ordre des lignes de code. Dans le flux de données, un nœud est exécuté quand les données sont valides sur tous ces terminaux d’entrée.
Quelquefois il est difficile de déterminer exactement l’ordre d’exécution. Souvent, certains événements doivent se dérouler avant d’autres événements. Quand vous avez besoin de contrôler l’ordre d’exécution des codes dans votre diagramme, vous pouvez utiliser la structure Séquence.
Structure Séquence : utilisée pour contrôler l’ordre dans lequel les nœuds seront exécutés dans un diagramme.
Dans le sous-menu « Execution control » :
● Regarder le film comme une suite d’images.
● Utilisé pour exécuter le diagramme de façon séquentielle.
● Clic droit sur le bord pour créer une nouvelle « image ».

25. While Loops LabVIEW While Loop Flow Chart Pseudo Code Repeat (code);
Until Condition met;
End;
While Loops execute a sequence of events while a condition is True (analogous to a “Do...While” statement).
While Loop functionality:
A While Loop executes the code contained inside it until a Boolean False is passed to the conditional terminal. Thus, it always executes at least once.
The iteration terminal contains the number of executions (zero-indexed).
LabVIEW While Loop Flow Chart Pseudo Code
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26. Select the Loop Condition
Click the Conditional Terminal with the Operating tool to define when the loop stops
Default: Stop if True
Iteration Terminal
Conditional Terminal
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27. For Loops LabVIEW For Loop Flow Chart Pseudo Code N=100; i=0;
Until i=N:
Repeat (code; i=i+1);
End;
A For Loop executes the diagram inside its border for a predetermined number of iterations (analogous to a “For...Next” statement).
Explain the difference between While Loops and For Loops:
While Loops run until a condition is met.
For Loops run a predetermined number of times.
LabVIEW For Loop Flow Chart Pseudo Code
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28. Insert a loop (example with white loop)
1. Select While Loop
2. Enclose code to be repeated
3. Drop or drag additional nodes and then wire
Place loops in your diagram by selecting them from the Structures palette of the Functions palette (demonstrate):
When selected, the mouse cursor becomes a special pointer that you use to enclose the section of code you want to repeat.
Click the mouse button to define the top-left corner, click the mouse button again at the bottom-right corner, and the While Loop boundary is created around the selected code.
Drag or drop additional nodes in the While Loop if needed.
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29. Wait Functions Wait Until Next ms Multiple
Functions»Time & Dialog palette
Take the time to carefully explain the above slide. This chart is also printed in the book; have them follow along on page 3-10.
Show how this function times on a ms Multiple; not a definite passage of time.
Show how you could lose some time on the first loop due to pre-loop code.
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30. Structure Tunnels Tunnels feed data into and out of structures.
The tunnel is a block that appears on the border; the color of the block is related to the data type wired to the tunnel.
When a tunnel passes data into a loop, the loop executes only after data arrive at the tunnel.
Data pass out of a loop after the loop terminates.
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31. Accessing Previous Loop Data – Shift Register
• Available at left or right border of loop structures
• Right-click the border and select Add Shift Register
• Right terminal stores data on completion of iteration
• Left terminal provides stored data at beginning of next iteration 5 5 10 10 15
Initial Value
Value 1
Value 2
Initial
Value
Final Value 15
Value 1
Value 2
Value 3
Shift registers transfer data from one iteration to the next:
Right click on the left or right side of a For Loop or a While Loop and select Add Shift Register.
The right terminal stores data at the end of an iteration. Data appears at the left terminal at the start of the next iteration.
A shift register adapts to any data type wired into it.
Stress why you need a shift register—to retain values from one iteration to the next.
Explain the slide in detail. Go slowly and repeat yourself.
Before Loop
Begins
First
Iteration
Second
Iteration
Last
Iteration
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32. Additional Shift Register Elements
Right-click the left terminal to add new elements
Previous values are available at the left terminals
Right-click the border for a new shift register
Latest value
is passed to
right terminal
1 loop ago
2 loops ago
3 loops ago
You can configure the shift register to remember values from several previous iterations.
Right click on the left terminal and choose Add Element to create additional terminals.
Explain the slide: The shift register allows you to access values from the past three iterations if you have three terminals.
This method is different from using separate shift registers:
One shift register with added terminals is storing multiple previous values of one variable.
Multiple shift registers maintain a single previous value of multiple variables.
Demonstrate the difference between adding a shift register vs. adding an element to a shift register.
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33. Exercise 7.1 Goal Concepts Homework
Replace continuous mode running by a while loop
Control data acquisition and display
Concepts
While loop, wait function,
Tunnel structure, shift register
Chart,
Homework
Open the vi that acquires a temperature with a choice stage for displaying the temperature either in Kelvin or Fahrenheit unit.
Insert while loop with wait function in order to control the speed from UI
Display in real-time generated temperature data with a chart (search for chart)
Display separately the last acquired data with its right unit
Insert shifts registers in order to average acquired signal over the 4 last acquisitions
Display signal and averaged signal on the same chart (search for how to connect chart for multiple plots, and especially the function “bundle”)
Save in « while.vi »
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34. Waveform Charts Selected from the Controls»Graphs and Charts palette
LabVIEW has three types of charts:
Strip chart: Scrolling display.
Scope chart: Retracing display. The plot is erased after reaching the right border of the plotting area.
Sweep chart: Like the scope chart, but the plot is not erased. Instead, a vertical line marks new data and moves across the display as data is added.
Place on the front panel by selecting the Graph subpalette of the Controls palette.
Because less overhead is involved in retracing the plot, scope and sweep charts are much faster. To increase the speed of the strip chart, disable the X axis.
Describe the graphic: A chart may have one trace or multiple traces.
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35. Wiring to Charts Single-Plot Chart Multiple-Plot Chart Bundle function
For a single plot, wire from the numeric control to the chart terminal.
For multiple traces, bundle each number together and then wire to the strip chart.
Open the chart example with the Example Wizard. It is important that students know that these examples are shipped with the package. If they have questions about how to wire to a strip chart, they have a good resource that shows all possible ways to display data on a chart.
Transition to next topic: Now we will discuss topics related to plotting: chart properties and mechanical action of booleans.
Bundle function
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36. Exercise FP
With simulation
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37. Exercise D
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38. Exercise 7.1 : complement 1
Try to initialize the chart (i.e to delete the chart history) at each run of the VI.
Try to adapt the y scale in function of the selected temperature unit
Save it as « while_adjusted.vi »
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39. Exercise 7.1 complement 1 - D (only for the initialization of the chart history)
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40. Summary Two structures to repeat execution: While Loop and For Loop
Loop timing controlled using Wait Until Next ms Multiple function, the Wait (ms) function, or the Time Delay Express VI.
Feedback nodes and shift registers transfer data values from one iteration to the next
Use shift registers only when more than one past iteration is needed
Do not immediately display this slide.
Suggested questions for class participation:
What structure must ALWAYS run at least once?
What structures are used to repeat execution of certain functions?
How can you control the speed at which the loop executes?
Describe the difference between the three types of charts.
Why would you want to use a shift register?
Why would you want to use a feedback node?
How do you retain multiple values from previous iterations?
Review the slide: The purpose of Lesson Four was to introduce LabVIEW structures. Structures control the flow of data in a VI.
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41. Lesson 8 Arrays and data analyzing
TOPICS
Introduction to Arrays
Auto Indexing Arrays
Array Functions
Polymorphism
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42. Arrays • Collection of data elements that are of same type
• One or more dimensions, up to 2 elements per dimension
• 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
1.7
2D array
Arrays are lists of elements of the same data type. They are analogous to arrays in traditional languages.
Arrays can have one or more dimensions.
Arrays can have up to 2^31 elements per dimension. Actual array sizes that students can create is limited by memory.
Elements are accessed by “index”. The index ranges from 0 to N-1 (N = number of elements in the array).
Arrays are zero-indexed (first element is zero) in each dimension.
A 2D array is analogous to a spreadsheet or table.
Example: Temperature readings and time stamp. One column is time values, and the other column is readings.
Point out element (2,3) and element (3,2) on the slide.
Be careful to specify the element you really want. Example: The first element in an array is array (0), not array(1). 1 2 3 4
Five row by seven column array of 35 elements
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43. Array Controls and Indicators
1. Select the Array shell from the Controls palette
2. Place data object inside shell
Creating arrays in LabVIEW:
Choose Array from the Array and Cluster palette
You can place any data type in an array shell except an array.
You cannot have an array of arrays; use a 2D array instead.
Two components: index and data object.
Emphasize that this is a two-step process. Students often place
only empty array shells on the front panel. Remind them they
must place a data type inside the array shell.
Demonstrate the following on your computer:
Create a numeric array.
Point out index and data object components.
Show how to create a 2D array.
Show how to display multiple array elements.
Show that index elements always reference the upper-leftmost
object in the array display.
Show how elements in an array are initially “grayed-out,”
indicating that a portion of the array has not been defined.
Add Dimension for 2D arrays
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44. Creating Array Constants
1. Select Array Constant shell from the Array subpalette
Creating array constants uses the same two-step process as a front
panel array.
Select an array constant from the Array subpalette of the Functions
palette.
Place a constant data type inside the empty array shell.
Note again that the data types are “grayed-out” and must be
manually defined if the user wants to store values in the array
constant.
2. Place the data object in the array shell
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45. Auto-Indexing
Auto-Indexing Enabled
Loops can accumulate arrays at their boundaries with auto-indexing
For Loops auto-index by default
While Loops output the final value by default
Right-click on tunnel and enable/disable auto-indexing
Wire becomes thicker
1D Array
Auto-Indexing Disabled
Wire remains the same size
For Loops and While Loops can index and accumulate arrays at
their boundaries. This is known as auto-indexing.
The indexing point on the boundary is called a tunnel.
The For Loop default is auto-indexing enabled.
The While Loop default is auto-indexing disabled.
Examples:
Enable auto-indexing to collect values within the loop and
build the array. All values are placed in array upon exiting
loop.
Disable auto-indexing if you are interested only in the final
value.
Only one value (last iteration) is passed out of the loop
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46. Creating 2D Arrays Inner loop creates column elements
You can use two nested For Loops to create a 2D array. Auto-
indexing must be enabled for both.
Inner loop creates column elements.
Outer loop creates row elements.
Explain the different line thicknesses.
Demonstrate on your computer:
How to change indexing and line thickness.
Enable Indexing in pop-up menu means indexing is currently
disabled. The menu choice is the opposite of the current index
mode. Students get confused about this feature.
Inner loop creates column elements
Outer loop stacks them into rows
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47. Exercise 8.1 Goal Create and anlyze table of datas Concepts
Tunnef structure with/without indexation function
Datas generated by loop : real time value, last acquired value, all values
Homework
Open the last vi (while_adjusted.vi”)
At the end of the program, display in a table, all generated value
Analyze datas : number of datas, mean, RMS, Min, Max, Range
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48. Exercise D
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49. Exercise FP
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50. Summary
Arrays group data elements of the same type. You can build arrays of numeric, Boolean, path, string, waveform, and cluster data types.
The array index is zero-based, which means it is in the range 0 to n – 1, where n is the number of elements in the array.
To create an array control or indicator, select an Array on the Controls»Array & Cluster palette, place it on the front panel, and drag a control or indicator into the array shell.
If you wire an array to a For Loop or While Loop input tunnel, you can read and process every element in that array by enabling auto-indexing.
By default, LabVIEW enables auto-indexing in For Loops and disables auto-indexing in While Loops.
Polymorphism is the ability of a function to adjust to input data of different data structures.
Do not immediately display this slide.
Suggested questions for class participation:
What is an array? Where might it be used?
How would I create a 2D array of numeric controls?
How can a loop create an array? Which loops can be used to do so?
What does “polymorphic” mean?
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51. Wiring the Block Diagram
Scalar
1D Array
2D Array
Numeric
Boolean
String
Not a complete list of data types; just ones that are used frequently through this course.
Explain that in LabVIEW, you use wires to connect multiple terminals together to pass data in a VI. The wires must be connected to inputs and outputs that are compatible with the data that is transferred with the wire, therefore understanding the different data types is key to correct wiring.
Explain the difference in colors and thicknesses.
Explain that arrays and strings will be covered later in the course.
Also, dynamic data type does not change width based on contents.
Students are often looking for a more detailed list of all the data types in LabVIEW. If they ask about that, point them to the Help >> VI, Function, & How-To Help… On the Index Tab, search for data types and double click on the keyword to get a display on all of the data types and terminal representations in LabVIEW.
Dynamic
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52. Lesson 9 Signal generation
TOPICS
Analog and digital signal generation
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53. Steps for creating an generation task
How to create a task to generate a tension ?
In Diagram, open Function Palette
Express > Input > Assistant DAQ
Analogous signal
Générer un signal > Sortie analogique > Tension
Digital signal
Générer un signal > Sortie numérique > Sortie de ligne (1 Voie) ou port (plusieurs voies)
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54. Steps for creating an generation task
How to create a task to generate an digital tension ?
In Diagram, open Palette de fonction
Express > Entrées > Assistant DAQ
Générer un signal > Sortie numérique > Sortie de ligne (ou port)
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55. Exercise 9.1 Goal Concepts Homework
Topic : Interface with LEDs and thermistance
Concepts
Analog and digital signal generation
LEDs alimentation : 0-5 Volts
Homework
Step 1: Acquire temperature every 200ms and define 2 controls for temperature limits T0 and T1.
Step 2 : When measured temperature is
less than T0, light up LED1 (green) with an intensity that depends on measured temperature.
greater than T0 and less than T1, light up LED2 (yellow) as a warning, and stop lighting up LED1
greater than T1, blink LED3 (red), and stop lighting up LED2
Step 3 : create and save historical data (time and data)
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56. Exercise D
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57. Lesson 10 Data saving TOPICS How to use several String functions
About file I/O operations
How to use the high-level File I/O Vis
How to format text files for use in spreadsheets
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58. 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
Write to Spreadsheet File: Converts a 1D or 2D array of numbers to a single-precision, tab-delimited string and writes the string to an ASCII file. Useful for quickly creating ASCII spreadsheet files as in the last slide.
Read from Spreadsheet File: Reads a tab-delimited ASCII file and converts the data back to a 1D or 2D array of numbers. Useful for reading data created with Write to Spreadsheet File, or data saved as an ASCII file from a spreadsheet program.
Write Characters to File: Writes a character string to a file.
Read Character from File: Reads a character string from a file.
Read Lines from File: Read a specified number of lines from an ASCII file.
All of the high-level VIs take care of opening/creating/replacing the file, reading/writing the file, and closing the file in one VI.

59. Data to string Date/Time Date to string Concatenate chain
Concatenated chain
Number to engineering string
Concatenated chain

60. Exercise 10.1 Goal Concepts Homework
Save temperature acquisitions into file
Concepts
Save datas into file
Homework
Open the last vi
Save datas and time into spreadsheet file
Save VI in « 13_Savefile.vi »
and read data from a new vi …

61. Summary
Use the File I/O VIs and functions located on the Functions»File I/O palette to handle all aspects of file I/O.
When writing to a file, you open, create, or replace a file, write the data, and close the file. Similarly, when you read from a file, you open an existing file, read the data, and close the file.
To access a file through a dialog box, do not wire file path in the Open/Create/Replace File VI.
To write data to a spreadsheet file, you must format the string as a spreadsheet string, which is a string that includes delimiters, such as tabs. Use the Format Into File function to format string, numeric, path, and Boolean data as text and write the text to a file
Suggested questions for class participation:
What are some uses of strings?
How are files opened using the Intermediate File I/O functions?
When is it preferable to write data to a file in ASCII format?
In binary integer format?
In what ways can you write to a spreadsheet file?

62. Lesson 11 Programming with Express VI
TOPICS
Save data
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63. Exercise 11.1 Goal Concepts Homework
Simulate, analyze and save only using Express VIs
Concepts
Express VI
Homework
Create a new vi that generates 2 signal independantly, filters the signal, indicates by a warning indicator if the signal amplitude exceeds a certain limit, and records the data when user ask. The speed of execution have to be controlled. Only with Express VIs

64. Exercise D
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65. Exercise F
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