1. LabVIEW Introduction
Alan Jennings

2. Programming in general
The Data:
MATLAB, C, Java
Variables, stack
LabVIEW, Simulink, FPGA
Connections (wires)
1 Output,
Many inputs
Excel
Predefined by cells
3/28/2012
Programming comparison

3. Programming in general
The Instructions: Inputs and outputs
MATLAB, C, Java, Excel
function, operator, method
[m,b]= linearfit(x, 3*x+4)
LabVIEW, Simulink, FPGA
Blocks with inputs and outputs
3/28/2012
Programming comparison

4. Programming in general
Structure: Order of execution
MATLAB, C, Java, Excel
Sequential: Line after line
Routing commands
Loops, conditional, break, goto,
LabVIEW,
As data is available
Loops
Simulink, FPGA
Blocks with inputs and outputs
FPGA physically simultaneous
Simulink numerically simultaneous
3/28/2012
Programming comparison

5. Setting up a LabVIEW Program
Front Panel
Controls: how the user controls the program
Indicators: Displaying results
Function Wiring for using your VI’s by other VI’s
Block Diagram
Data: All controls and indicators, Also constants
Doing something: Add functions
Control what happens: Add structure
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LabVIEW Components

6. Front Panel Inputs: Number, Array, Matrix File names, Categories
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LabVIEW Components

7. Front Panel
Inputs:
Binary More Numeric
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LabVIEW Components

8. Function Blocks Icons Blocks Default values Using Context help
Icons: little to no description
Function Blocks
Icons
Blocks
Default values
Using Context help
Hover over icons, blocks or wires to see what it is and the different signals
Blocks expand to show all possible signals
3/28/2012
LabVIEW Components

9. Loops For Loop While Loop Sequence loops Case loops
Indexing over arrays
While Loop
Wait for an event to stop (such as user or trigger)
Feedback block
Sequence loops
Specify execution order
Important for local variables
Case loops
Conditional Execution
3/28/2012
LabVIEW Components

10. Data Types Waveforms Arrays (column) 2d Arrays
Values, to, Sample frequency
Arrays (column)
2d Arrays
Clusters (similar to structures)
Objects (typical for controlling DAQ’s, etc)
Easiest thing to do is use the port and create constant to see
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LabVIEW Components

11. Ex: Finding Largest Value
Generate Data
Compare each value to current best
3/28/2012
Programming Examples

12. Ex: Finding Largest Value
Generate Data
Use Gaussian generation block
Set standard deviation and number of samples
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
3/28/2012
Programming Examples

13. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value 1 5 2 3 4 6 4 3
3/28/2012
Programming Examples

14. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
These are controlled by the front panel
3/28/2012
Programming Examples

15. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
3/28/2012
Programming Examples

16. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
To pull of individual values, convert to an array
Other blocks may require other formats
3/28/2012
Programming Examples

17. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
Pull the 0 index as the initial condition
Use it to initialize feedback block
3/28/2012
Programming Examples

18. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
Indexed (pulls each value)
Non-Indexed (returns last)
Non-Indexed
3/28/2012
Programming Examples

19. Ex: Finding Largest Value
Generate Data
Set standard deviation and number of samples
Use Gaussian generation block
Convert data type
Compare each value to current best
Initialize the current largest value
Use `for’ loop to index over signal
Change selection based on logic test
Ex: Finding Largest Value
Flow if current largest is largest
Flow if current value is largest
3/28/2012
Programming Examples

20. Ex: Approximating Human Control
Dynamic System
Generate disturbance,
Or possibly tracking path
Find the command as function of error and its derivative
Do linear fit to find average gain values
Find how well the gains describe behavior
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Programming Examples

21. Ex: Approximating Human Control
TankControl.vi
Simple Tank Control (loss proportion to height)
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Programming Examples

22. Ex: Approximating Human Control
TankControl_2.vi
Include maximum time
Do linear estimation of control policy
Use local variables
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Programming Examples

23. Ex: Approximating Human Control
Doesn’t Work!
Zeros for linear fit first time
Troubleshooting planar fit error
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Programming Examples

24. Ex: Approximating Human Control
TankControl_3.vi
Add 2D and 3D graphs
Add control for set point
Add start button
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Programming Examples

25. I didn’t say the graphs looked good.

26. Sequence loop separates activation

27. Data Type conversions to use graphics
Need to separate the array and bundle x & y as pairs

28. Other Program Challenges
Programming Problems:
Finding prime numbers
Binary to dec converter
tausiq.wordpress.com/2009/07/27/push-ups-with-blaze/
Rock, paper, scissor tournament
Currency Converter
Verifying 8 Queens
3/28/2012
Programming comparison