LabVIEW For FRC Programming Fundamentals

1. You want to find where a control on the Front Panel is being used in your code. What is the quickest way to find the control's terminal on the Block Diagram?

Open the Block Diagram and, starting in the upper left corner, look for a matching terminal.

Use to search for the name of the control.

Inputs/Outputs, Front Panel/Block Diagram

Explanation

Inputs/Outputs, Front Panel/Block Diagram

2. If you want find a way to perform math functions in LabVIEW, where would you find the relevant LabVIEW primitives and subVIs?

Functions Palette » Programming » Numeric

Controls Palette » Modern » Array, Matrix & Cluster

Functions Palette » Programming » Comparison

Controls Palette » Modern » List, Table & Tree

Using Pallets to Find Functions

Explanation

Using Pallets to Find Functions

3. While testing your new encoder, you want to display the output value in the Encoder Value indicator on the Front Panel of a VI. Which of the following options should you use?

Inputs/Outputs, Front Panel/Block Diagram I

Explanation

Inputs/Outputs, Front Panel/Block Diagram I

4. LabVIEW is used widely in nearly every science and engineering industry across the globe. Which of the following are examples of industries that use LabVIEW? (SELECT ALL THAT APPLY.)

Automotive and Energy

Military/Defense and Aerospace

Scientific Research and Medical Research

Robotics and Manufacturing

Awareness of LabVIEW in Industry

Explanation

Awareness of LabVIEW in Industry

Submit

5. Which of the following is the keyboard shortcut to enable/disable Context Help?

Ctrl + H

Ctrl + C

Ctrl + Shift + H

Ctrl + Shift + C

Using Built-in Resources and Help

Explanation

Using Built-in Resources and Help

6. Being able to combine different inputs can be useful when attempting to have your robot autonomously make decisions. Which function will take the inputs shown in String 1, String 2, and String 3 and generate the output shown below?

Inputs/Outputs, Front Panel/Block Diagram I

Explanation

Inputs/Outputs, Front Panel/Block Diagram I

7. You enter Ctrl + H to enable Context Help and hover your mouse over a subVI you do not recognize. One of the inputs for the subVI has a bolded name. For example, the RobotDriveDevRef input is bolded for the Tank Drive subVI. What does this mean?

This is the first input you should enter. All other input values are derived based on this input.

This input has a constant value that you cannot change. You do not need to wire the input.

Using Built-in Resources and Help

Explanation

Using Built-in Resources and Help

8. LabVIEW reports an error number you do not recognize. Where is the best place to get more information about the error?

Select Explain Error from the Help Menu on the toolbar.

Read the LabVIEW documentation.

Run the code until you can see what is causing the error.

Find an example that has the same error and read the comments explaining it.

Troubleshooting LabVIEW Code

Explanation

Troubleshooting LabVIEW Code

9. The String Subset function is useful for pulling out pieces of longer strings. Given the code shown below, what would be the result in Output?

Awesome

LabVIEW

IsAwesome

Some

SubVIs and Functions

Explanation

SubVIs and Functions

10. Case structures are a great way to run conditional code. All cases of the case structure are displayed below. What will the Numeric indicator display after the code runs?

0

15

-5

5

Case Structures

Explanation

Case Structures

11. While you are wiring up your code, you notice that some of your wires are broken. Why is the wire broken in the code shown below from the Teleop.vi?

You have wired a Boolean to a Double input.

You have wired an array into a single-value input.

You have wired an output to an input.

You have wired an Integer to a Boolean input.

Troubleshooting LabVIEW Code I

Explanation

Troubleshooting LabVIEW Code I

12. Your game controller's buttons are elements 0 and 1 in the button array. Which of the following is the best way to read both of these values?

Expand the Index Array VI down to allow for two outputs.

Place two Index Array VIs and get one button value from each.

Use the value from button 0 wherever button 1 is required.

Indexing Arrays

Explanation

Indexing Arrays

13. If you want to perform string manipulation, where would you find the relevant LabVIEW primitives and subVIs?

Functions Palette » Programming » String

Controls Palette » Modern » String & Path

Functions Palette » Programming » Comparison

Controls Palette » Modern » List, Table & Tree

Using Pallets to Find Functions

Explanation

Using Pallets to Find Functions

14. When is the best time to place probes on wires in your application?

During debugging to see real-time values.

After you've tested your robot and know it works.

Before saving your VI to ensure they are visible next time.

While you're developing your robot code in case you need them later.

Troubleshooting LabVIEW Code

Explanation

Troubleshooting LabVIEW Code

15. Engineers, scientists, and researchers are doing some truly amazing things with LabVIEW. Which of the following are examples of applications that are using LabVIEW? (SELECT ALL THAT APPLY.)

Developing the world's first functional prototype of a semi-autonomous blind driver vehicle

Developing an engine simulator test system to enhance the performance of gas turbine engine controllers

Intercepting misguided and unstable particle beams in the world's most powerful particle accelerator

Controlling and monitoring astronauts' heart rate monitors on the International Space Station

Awareness of LabVIEW in Industry

Explanation

Awareness of LabVIEW in Industry

Submit

16. Case structures are a great way to implement conditional code. The code below determines which autonomous code to run, based on the robot's starting location in the match. All cases of the case structure are shown below. What will the output of the case structure be when this code runs?

Autonomous 1

Autonomous 2

Autonomous 3

Cannot be determined

Case Structures

Explanation

Case Structures

17. If you want to perform array manipulation, where would you find the relevant LabVIEW primitives and subVIs?

Functions Palette » Programming » Array

Controls Palette » Modern » Array, Matrix, and Cluster

Functions Palette » Programming » Comparison

Controls Palette » Modern » List, Table, and Tree

Using Pallets to Find Functions

Explanation

Using Pallets to Find Functions

18. Engineers, scientists, and researchers are doing some truly amazing things with LabVIEW. Which of the following are examples of applications that are using LabVIEW? (SELECT ALL THAT APPLY.)

Developing and prototyping bearingless magnetic-levitation blood pumps for life support

Developing interplanetary robotic systems, including a ground-based demonstrator arm for the Mars rovers

Providing high-quality data processing in cutting edge flight test engineering education

Creating a cluster of autonomous robots that can simulate satellite dynamics in space

Awareness of LabVIEW in Industry

Explanation

Awareness of LabVIEW in Industry

Submit

19. You receive the following error in the Driver Station when you deploy your robot code and enable your robot:

Looking at the below snippets from Begin.vi and Teleop.vi, what is the causing the error?

The motor refnum names do not match.

The Safety Config should have been disabled in Begin.vi.

The motor refnum name should have been Drivetrain Motors.

The motors should have been initialized in Teleop.vi.

Troubleshooting LabVIEW Code II

Explanation

Troubleshooting LabVIEW Code II

20. You add the following motor code for your Lift Motor (which is correctly initialized) in Teleop.vi. After adding the code, you notice Teleop.vi has a broken Run Arrow. Looking at the code snippet and the Context Help window below, why is this VI broken?

The MotorControlDevRef needs to be wired.

The options need to be set.

Output should be a Boolean value.

The error wire should not be wired.

Troubleshooting LabVIEW Code II

Explanation

Troubleshooting LabVIEW Code II

21. Shift registers are used to pass values to subsequent iterations of loops. What will the Output indicator display be after the loop completes its second iteration (i=1)?

3

4

7

6

Loops

Explanation

Loops

22. If you want to use Boolean logic to make a decision in your VI, where would you find the relevant LabVIEW primitives and subVIs?

Functions Palette » Programming » Boolean

Controls Palette » Modern » Array, Matrix, and Cluster

Functions Palette » Programming » Comparison

Controls Palette » Modern » List, Table, and Tree

Using Pallets to Find Functions

Explanation

Using Pallets to Find Functions

23. The autonomous selector uses a string to select which case to run. What color wire connects the string input to the case selector terminal?

Pink

Orange

Blue

Green

Wires and Data Types

Explanation

Wires and Data Types

24. Which of the following is always an output?

Indicator

Control

Constant

Typedef

Inputs/Outputs, Front Panel/Block Diagram

Explanation

Inputs/Outputs, Front Panel/Block Diagram

25. Case structures are a great way to run conditional code. All cases of the case structure are displayed below. What will the Numeric indicator display after the code runs?

15

0

-5

5

Case Structures

Explanation

Case Structures

26. Which of the following is always an input?

Control

Indicator

Typedef

Terminal

Inputs/Outputs, Front Panel/Block Diagram

Explanation

Inputs/Outputs, Front Panel/Block Diagram

27. The data from a game controller's button is carried on which color wire?

Green

Blue

Orange

Pink

Wires and Data Types

Explanation

Wires and Data Types

28. To give your driver increased control, you might want to use a button to decrease motor speed. To do this, you will need to get a value from both the buttons array and the axes array. What would be the best way to do this?

Wire both arrays into a single Index Array to combine all the joystick outputs.

Change the button to another axis so that you no longer have two arrays.

Use Build Array to combine the two arrays into one array. Then make that the input for Index Array

Indexing Arrays

Explanation

Indexing Arrays

29. Shift registers are used to pass values to subsequent iterations of loops. Given the While Loop below, what value would the Output indicator display when the loop completes its second iteration (i=1)?

3

2

1

4

Loops

Explanation

Loops

30. You tried to build your project to deploy it to your robot but received the following error during the build process. You notice that all the affected VIs are associated with the Vision Acquisition Software. How would you resolve this error?

Activate the Vision Acquisition Software.

Delete the problematic VIs from your project.

Add the problematic VIs as Dependencies in your project.

Uninstall the Vision Acquisition Software from your computer.

31. The code below shows how to implement a one-shot button. What is the function of the AND primitive?

It outputs a TRUE if both inputs are TRUE.

It outputs a FALSE if both inputs are TRUE.

It outputs a TRUE if both inputs are FALSE.

It outputs a TRUE if one input is TRUE and one input is FALSE.

Logic Functions

Explanation

Logic Functions

32. You have created a subVI to read sensor values and placed it in Teleop.vi, Autonomous.vi, and Periodic Tasks.vi. You open the subVI from Teleop.vi, make changes to the subVI, and save it. Which instances of the subVI are updated?

The subVI is updated everywhere.

Only the subVI in Teleop.vi is updated.

The subVIs in Teleop.vi and Autonomous.vi are updated.

The subVIs in Teleop.vi and Periodic Tasks.vi are updated.

SubVIs and Functions

Explanation

SubVIs and Functions

33. The Stop terminal in a While Loop controls when the loop will stop iterating. How many iterations will the given While Loop execute before stopping?

1

2

3

Infinite

Loops

Explanation

Loops

34. The code below shows how to implement a one-shot button. What is the function of the Not primitive?

It inverts the output of the Feedback Node.

It doubles the output of the Feedback Node.

It only passes the output of the Feedback Node through if it is a TRUE value.

It resets the output of the Feedback Node to the default value.

Logic Functions

Explanation

Logic Functions

35. LabVIEW automatically provides some frequently used specific string constants. What does the following string constant represent?

A space constant

An end-of-line constant

A tab constant

An empty string constant

Inputs/Outputs, Front Panel/Block Diagram I

Explanation

Inputs/Outputs, Front Panel/Block Diagram I

36. What happens if you drag a VI directly from your Robot Project to the Block Diagram of another VI?

The VI is placed as a subVI.

LabVIEW asks if you want to add the Block Diagram to your project.

The cursor shows a red X on the Block Diagram and nothing happens.

LabVIEW combines the Block Diagrams of the two VIs.

SubVIs and Functions

Explanation

SubVIs and Functions

37. Your VI is broken, and clicking on the broken Run Arrow displays this Error List popup window. Where is the best place to start looking for the problem?

NT Write Numeric Array.vi

NT Server.vi

Robot Main.vi

WPI_CameraSend Images To PC Loop.vi

Troubleshooting LabVIEW Code

Explanation

Troubleshooting LabVIEW Code

38. What will the Output indicator display after the VI is run?

FALSE

TRUE

0

Cannot be determined

Logic Functions

Explanation

Logic Functions

39. The FRC Update Suite installs examples to help program your robot. How do you navigate to these examples?

From the Help Menu, choose Find Examples. This will open up the FRC Robotics folder of examples.

Go to www.ni.com/frc and choose Open LabVIEW Examples.

LabVIEW displays a welcome screen. Choose the appropriate example under the Open heading.

Enter to bring up the Example Finder.

Using Built-in Resources and Help

Explanation

Using Built-in Resources and Help

40. While you are wiring up your code, you notice that some of your wires are broken. Why is the wire broken in the code shown below from Teleop.vi?

You have wired an array into a single-value input.

You have wired a Double to a Boolean input.

You have wired an output to an input.

You have wired an Integer into a Double.

Troubleshooting LabVIEW Code I

Explanation

Troubleshooting LabVIEW Code I

41. How do you select the correct button from Index Array if the button is the 7th element?

Wire an integer constant of 6 into the element input.

Wire an integer constant of 7 into the element input.

Nothing extra is required; the Index Array function automatically determines which elements are updating and outputs only those elements.

Wire the entire array into your subVI.

Indexing Arrays

Explanation

Indexing Arrays

42. The data from a game controller's analog stick or thumbstick is carried on what color wire?

Orange

Blue

Pink

Green

Wires and Data Types

Explanation

Wires and Data Types

43. Which search term below would NOT return the Index Array function at the top of the list when typed into the block diagram's Quick Drop?

Array

Dex

Index

Ndx

Using Search or Quick Drop to Find Functions

Explanation

Using Search or Quick Drop to Find Functions

44. Case structures are a great way to implement conditional code. The code below determines which autonomous code to run, based on the robot's starting location in the match. All cases of the case structure are shown below. What will the output of the case structure be when this code runs?

Autonomous 3

Autonomous 2

Autonomous 1

Cannot be determined

Case Structures

Explanation

Case Structures

45. Quick Drop allows you to rapidly find and place LabVIEW front panel and block diagram objects without navigating the palettes or initiating a search. What keyboard shortcut accesses Quick Drop?

Ctrl + Space

Ctrl + Q

Ctrl + D

Ctrl + Q + D

Using Search or Quick Drop to Find Functions

Explanation

Using Search or Quick Drop to Find Functions