Labview Exam

Question 1

Data Aquisition

Answer 1

The process of measuring an electrical or physical phenomenon with a computer

Question 2

Signal Type: Analog

Answer 2

Signals that vary continuously (temperature)

Question 3

Signal Type: Digital

Answer 3

Electrical signals that transfer binary data, such as on/off or true/false (switches)

Question 4

Signal Type: Counter

Answer 4

Digital timing signal that includes characteristics of a digital signal that can be measured (event counting)

Question 5

List the order of a DAQmx application process

CCSACC

Answer 5

C /reate task
C /onfigure task
S /tart task
A /cquire or generate data
C /lear task
C /heck for errors

Question 6

Hardware Connectivity

Answer 6

The physical cable connecting the instrument

Question 7

Describe: Initialize

Answer 7

Establishes communication with the instrument

Question 8

Describe: Configure

Answer 8

Software routines that configures the instrument to perform specific operations

Question 9

Describe: Action/Status

Answer 9

Command the instrument to carry out an action or obtain the current status

Question 10

Describe: Data

Answer 10

Transfer data to or from the instrument

Question 11

Describe: Utility

Answer 11

Performs a variety of auxiliary operations; reset and self test

Question 12

Describe: Close

Answer 12

Terminates the software connection to the instrument

Question 13

What is a NI MAX?

Answer 13

A tool to configure and test DAQ devices AND test instrument communication

Question 14

What are benefits of instrument control?

Answer 14

Automate processes AND improve productivity and repeatability

Question 15

VISA is a high level API that calls low-level drivers.

True or False

Answer 15

True

Question 16

Define Low-Level File I/O

Answer 16

Provides individual functions for each step in file I/O operations

Question 17

Define File Refnums

Answer 17

Identify unique I/O sessions

Question 18

Define Streaming Data to Disk

Answer 18

Technique for keeping files open while you perform multiple write operations

Question 19

Define String Functions

Answer 19

Write data to text file, must first convert the data into sting type

Question 20

Define ASCII

Answer 20

Binary file that is standard used to by most programs. Also called text files

Question 21

Define LVM

Answer 21

Tab-delimited text file you can open with a spreadsheet application or a text-editing application

Question 22

Define Binary

Answer 22

Underlying file format of all other file formats

Question 23

Define TDMS

Answer 23

Binary file created for National Instruments products. Consists of two seperate files- binary file contains data and stories its properties and provides said information

Question 24

After opening a file, which output does the Open/Create/Replace File I/O function return?

Answer 24

Refnum out

Question 25

Which file format is best in an application that requires high-speed streaming?

Answer 25

TDMS

Question 26

Sequential Programming

Answer 26

Ensures the execution order of tasks

Question 27

State Machine

Answer 27

Has a while loop and case structure

Question 28

Sequence Structures

Answer 28

Contains one or more sub diagrams, or frames, that execute in sequential order

Question 29

State

Answer 29

Part of a program that satisfies a condition, performs an action or waits for an event

Question 30

Transition

Answer 30

Condition, action, or event that causes the program to move to the next state

Question 31

Event-based State Machine

Answer 31

Combine a user interface event handler with the transition ability of the state machine

Question 32

When using a sequential structure, you can stop the execution in the middle of a sequence? True/False

Answer 32

False

Question 33

You can: change the order of the sequence repeat individual items in the sequence set conditions to determine when an item should execute stop the program at any point in the sequence

Answer 33

These are the benefits of using a state machine instead of a sequential structure

Question 34

Variables

Answer 34

Block diagram elements that access or store data in another location

Question 35

When to use a Local Variable

Answer 35

Initializing front panel controls or indicators Write to controls Keeping parallel loops parallel

Question 36

Draw back of variables

Answer 36

Less readable on block diagram Limited boolean mechanical actions Unexpected behavior in VI

Question 37

Race Condition

Answer 37

Occurs when the timing of events or the scheduling of tasks unintentionally affects an output or data value

Question 38

Race conditions commonly occur in programs that:

Answer 38

Execute multiple tasks in parallel Share data Have two tasks with both read and write access

Question 39

You should use variables in your VI whenever possible. | True/False

Answer 39

False

Question 40

When controlling resources, which combination(s) of writers and readers reduces the chance of race conditions?

Answer 40

One writer, one reader AND one writer, multiple readers