LabVIEW Cert
functions palette
contains the VIs, functions and constants you use to create the block diagram
controls palette
contains the controls and indicators you use to create the front panel
block diagram
contains the graphical source code; contains terminals for front panel controls and indicators
build text VI
creates text, usually for displaying on the front panel window or exporting to a file or instrument
password display
displays an asterisk (*) for each character including spaces
'\' codes display
displays backslash codes for all non-displayable characters
context help window
displays basic information about LabVIEW objects when you move the cursor over each object
normal display
displays printable characters using the font of the control; non-displayable characters generally appear as boxes
hex display
displays the ASCII value of each character in hex instead of the character itself
color copy tool
dropper in a box icon; use this tool to copy colors for pasting with the coloring tool
front panel indicators VI
examples include waveform chart, waveform graph, and XY graph
owned labels
explain data contents of wires and objects; move with object; have transparent backgrounds; created by selecting Visible Items>>Label from the shortcut menu
operating tool
finger pointing icon; use this tool to change the values of a control
components of a VI
front panel block diagram icon/connector pane
simulate signal VI
generates simulated data such as a sine wave
enums
give users a list of items from which to select; are useful because they make strings equivalent to numbers, which are easy to manipulate on the block diagram; each item represents a pair of values: a string value and a 16-bit integer
scrolling tool
hand in a box icon; use this tool to scroll through windows without using scrollbars
d. the value passed into a node was converted to a different representation
if an input to a function is marked with a red dot (known as coercion dot), what does the dot indicate? a. data was transferred into a structure b. that input has not been wired c. the wire is broken d. the value passed into a node was converted to a different representation
run
if the _____ button appears broken when you finish wiring the block diagram, the VI is broken and cannot run
Build Specifications
includes build configurations for source distributions and other types of builds available in LabVIEW toolkits and modules
controls
interactive input; knobs, push buttons, dials, and other inputs; simulate instrument input devices and supply data to the block diagram
object shortcut menu tool
cursor and square divided into three sections icon; use this tool to access an object shortcut menu with the left mouse button
positioning tool
cursor icon; use this tool to select or resize objects
common causes of broken VIs
- broken wire due to mismatch of data types - required terminal is unwired - control wired to another control - broken subVI due to unwired required terminal
free labels
describe algorithms; have fixed location; have pale yellow backgrounds; created by double-clicking in any open space
any nonzero value; true
If the 8-bit value __________, the Boolean value is _______.
zero; false
If the 8-bit value is _____, the Boolean value is ______.
8-bit values
LabVIEW stores Boolean data as ______________
probe tool
P in a circle with arrow going through it icon; use this tool to create probes on wires on the block diagram; use this tool to check intermediate values in a VI that produces questionable or unexpected results
front panel, block diagram, icon/connector pane
What are the three parts of a VI? a. front panel b. block diagram c. project d. icon/connector pane
code
a 32-bit signed integer that identifies the error numerically; a non-zero error code is coupled with a status of FALSE signals a warning rather than an error
status
a boolean value that reports TRUE if an error occurs
NaN (not a number)
a floating-point value that invalid operations produce, such as taking the square root of a negative number
inf (infinity)
a floating-point value that valid operations produce, such as dividing a number by zero
LabVIEW
a graphical programming environment you can used to develop sophisticated measurement, test, and control systems
string data type
a sequence of ASCII characters; use these controls to receive text from the user such as a password or user name; use these indicators to display text to the user
string
a sequence of displayable or non-displayable ASCII characters; provide a platform-independent format for information and data
source
a string that identifies where the error occurred
express VIs
a type of subVI that you configure with dialog boxes; icons for these appear on the block diagram as icons surrounded by a blue field; designed specifically for completing common, frequently used operations; use the dynamic data type to pass data between Express VIs
DAQ Assistant VI
acquires data through a data acquisition device
Instrument I/O Assistant VI
acquires instrument control data, usually from a GPIB or serial interface
error handling
anticipation, detection, and resolution of warnings and errors
subVIs
are VIs that run on the block diagram of another VI; they have front panels and block diagrams; any VI has the potential to be used as this; when you double-click this, the front panel and block diagram open
functions nodes (functions)
are fundamental operating elements of LabVIEW and do not have front panels or block diagrams; have pale yellow backgrounds
icon
are the graphical representation of VIs; use this from the upper-right corner of the front panel as the _____ that appears when you place the subVI on a block diagram; can contain text, images, or a combo of both; if you use a VI as a subVI, the ______ identifies the subVI on the block diagram of the VI
automatic error handling
at run time, LabVIEW suspends execution, highlights node where error occurred, and displays Error dialog box
green wire
boolean
coloring tool
box on another box icon next to a paintbrush icon; use this tool and the color picker to color an object; this tool displays the current foreground and background color settings; select this tool and right-click an object or workspace to display the color picker
icons; expandable nodes
by default, subVIs appear as ______ on the block diagram, and Express VIs appear as _____ _____
statistics VI
calculates statistical data from a waveform; this includes mean, sum, standard deviation, and extreme values
numeric data type
can represent numbers of various types, such as integer or real; the two common _____ objects are the ____ control and the _____ indicator
waveform data type
carries the data, start time, and dt of a waveform
indicators
interactive output; graphs, LEDs, and other displays; simulate instrument output devices and display data the block diagram acquires or generates
connector pane
is the map of inputs and outputs of a VI; these terminals correspond to the controls and indicators on the front panel of the VI; you cannot access this from the block diagram window; similar to the parameter list of a function call in text-based programming languages; defines the inputs and outputs you can wire to the VI so you can use it as a subVI; receives data at its input terminals and passes the data to the block diagram code through the front panel controls and receives the results at its output terminals from the front panel indicators
front panel
is the user interface; has controls (inputs) and indicators (outputs)
dataflow
labVIEW follows a _______ model for running VIs
different control palettes
modern silver classic systems difference is the display style; only for the front panel
orange wire
numeric (floating-point)
blue wire
numeric (integer)
nodes
objects on the block diagram that have inputs and/or outputs and perform operations when a VI runs; are analogous to statements, operators, functions, and subroutines in text-based programming languages; can be functions, subVIs, or structures
breakpoint tool
octagon with arrow pointing out of it icon; use this tool to set breakpoints on VIs, functions, nodes, wires, and structures to pause execution at that location
project root
part of the Project Explorer; contains all other items in the Project Explorer window; includes the filename for the project
Dependencies
part of the Project Explorer; includes VIs and items that VIs under a target require
My Computer
part of the Project Explorer; represents the local computer as a target in the project
spectral measurements VI
performs spectral measurement on a waveform, such as magnitude and power spectral density
amplitude and measurements VI
performs voltage measurements on a signal; these include DC, rms, maximum peak, minimum peak, peak to peak, cycle average, and cycle rms measurements
filter VI
processes a signal through filters and windows; filters used include the following: highpass, lowpass, bandpass, bandstop, and smoothing
read from measurement file VI
reads a file that was created using the Write to Measurement File Express VI; specifically reads LVM or TDM file formats; does not read ASCII files
boolean data type
represents data that only has two possible states, such as TRUE and FALSE or ON and OFF; use these controls and indicators to enter and display boolean values
icon/connector pane
represents the VI and makes it possible to use the VI as a subVI; maps the inputs and outputs to the VI
merge errors
returns the first error found; if no error is found, it returns the first warning; does not concatenate errors; use to propagate errors along wires; use to merge errors from different wire paths
tone measurements VI
searches for a single tone with the highest frequency or highest amplitude; also finds the frequency and amplitude of a single tone
yes. A well-designed block diagram typically flows from left to right. This makes it easier to see the flow of data on the block diagram. However, do not assume left-to-right or top-to-bottom execution when no data dependency exists.
should a well-designed block diagram flow in a particular direction?
wiring tool
spool icon; use this tool to wire objects together on the block diagram
warnings
status = FALSE and code = non-zero; less severe; node executes normally, but it is important to monitor warnings during development to ensure proper behavior of your application
errors
status = TRUE and code = non-zero; more severe; passed to the next node without executing that part of the code
dynamic data type
stores the information generated or acquired by an Express VI
path data type
stores the location of a file or directory using the standard syntax for the platform you are using
pink wire
string
block diagram objects
terminals subVIs functions constants structures wires
terminals
the entry and exit ports that exchange information between the front panel and block diagram; can view as icon conserve space
block diagram terminals
these visually communicate information about the data type represented. Terminal colors, text, arrow direction, and border thickness all provide visual information about the terminal.
boolean text
this text appears only on the front panel, and by default, appears in the center of the Boolean control
control label
this text identifies the terminal of the Boolean control for programming purposes; this text does not appear on the front panel unless you select Visible
wires
transfer data between block diagram objects
labeling tool
typing cursor in a box icon; use this tool to enter text in a control, to edit text, and to create free labels
error cluster
use these controls and indicators to create error inputs and outputs in subVIs
shortcut menus
use these items to change the appearance or behavior of objects
error list dialog box
use this to locate the source of errors and warnings, and get more detailed information about the problem
breakpoint tool
use this tool to place a breakpoint on a VI, node, or wire and pause execution at that location
statistics
which Express VI is best suited to determining the average value of the acquired data a. tone measurements - finds the frequency and amplitude of a single tone b. statistics - calculates statistical data from a waveform c. amplitude and level measurements - performs voltage measurements on a signal d. filter - processes a signal through filters and windows
write to measure file and waveform graph
which Express VIs and/or indicators are best suited to displaying the data on a graph and logging the data to file a. DAQ Assistant - acquires data through a data acquisition device b. write to measurement file - writes a file in LVM or TDM file format c. build text - creates text, usually for displaying on the front panel window or exporting to a file or instrument d. waveform graph - displays one or more plots of evenly sampled measurements
DAQ Assistant
which express VI is best suited to acquire a sine wave from a data acquisition device a. DAQ Assistant - acquires data through a data acquisition device b. Instrument I/O Assistant - acquires instrument control data, usually from a GPIB or serial interface c. Simulate Signal - generates simulated data, such as a sine wave
c. latch when pressed
which mechanical action causes a Boolean control in the FALSE state to change to TRUE when you click it and stay TRUE until LabVIEW has read the value? a. switch until released b. switch when released c. latch when pressed d. latch when released
a. a subVI is broken c. a required subVI input is unwired d. a boolean terminal is wired to a numeric indicator
which of the following will result in a broken run arrow a. a subVI is broken b. the diagram includes a divide by zero c. a required subVI input is unwired d. a boolean terminal is wired to a numeric indicator
Project Explorer
window to manage projects in LabVIEW
automatic tool selection
wrench and screwdriver icon next to a rectangular shape icon; when this is selected, LabVIEW automatically chooses a tool based on the location of your cursor; can be turned off by simply pressing this button or by selecting another item on the palette
write to measurement file VI
writes a file in LVM or TDMS file format
icons; expandable nodes
you can display VIs and Express VIs as either _______ or _______ __________
manual error handling
you control when dialog boxes appear, propagate errors through error in/error out clusters, terminate error chain with Simple Error Handler