LabVIEW certification

coordinants

[3.4] the numbers 3 and 4 are elements the 3 is the number of rows the 4 is the number of columns

state machine VI

always has case structure, several states, requires user inputs, always has a default state

block diagram

blank page, build logic here

formula box

calculator. express, arithmetic, formula. label xs with representative inputs and results

subVI

cannot edit from functions palette you must have an icon/connector to use it the color of the connector pane will match the data type it is connected to the connector pane defines where to wire inputs and outputs

latch until released

change state on a button press. Change back when released and read by LabVIEW

latch when pressed

change state on a button press. change back when the control is read by LabVIEW

switch when pressed

change state on a button press. remain there until another button press

latch when released

change state on a button release. change back when the control is read by LabVIEW

switch when released

change state on a button release. remain there until another button release

switch until released

change state on a button press. change back when the button is released

Error Cluster

components: source code status

diamond

conditional test (flowcharting)

control refnum

connect to

circle

connect to another loop

wires (lines)

connectors

VI

virtual instrument

property nodes

-allow attributes of front panel objects to be programmatically manipulated -can be use to update values in front panel object -more than one can be used fr a single front panel object -when contained in subVI, will always cause front panel to be loaded in memory

oval

start, stop (flowcharting)

Sweep Chart

This mode acts much like the scope chart, but the plot is not erased when the plot hits the right border. Instead, a moving vertical line marks the beginning of new data and moves across the display from left to right as it adds new data.

Scope Chart

This mode has a retracing display similar to an oscilloscope. As it receives each new value, it plots the value to the right of the last value. When the plot reaches the right border of the plotting area, it erases the plot and begins plotting again from the left border.

Strip Chart

This mode has a scrolling display that is similar to a paper tape strip chart recorder. This mode first plots values from left to right. From here, it continues to plot new points at the rightmost point and shifts old values to the left.

type definition

custom control used to ensure that the data type is the same anywhere the control is used (looks like a dialog input box) required for case selector input of a functional global variable (has small black triangle in corner of box)

single stepping

debugging tool, once you've paused the VI, you can execute it one step at a time. The options are shown in the operate menu

breakpoint

debugging tool; right click on wire to pause execution at that location

conditional/case structures

depend on a condition to be met

shape

derived from rank and extent

XY graphs

display data acquired at a non-constant rate and data for multivalued functions

waveform graphs and charts

display data at constant rate (periodic)

front panel

gridded page, controls and displays

variant

handles data of many different types in a generic way represents any data type increases degree of generality passes values between programs written with different compilers

race conditions

if multiply wires to the same variable, no guaranteed order has no coordinate system to say which goes first or when they will start simply having two different timers does not determine an order

control refnum

if you drag a control (an input) to this, you will remove the original control and create a strictly typed __. these accept only ____ of exactly the same data type

control

input (LABview)

case structure: selector terminal

input data can be a Boolean, string, integer, enumerated type or error cluster

parallelogram

inputs and outputs (flowchart)

for loop

iterates a given number of times. the N is number of iterations, the counter/index records which iteration the loop is on. inside the box is the operation to be performed control goes to N, array goes to index, and index indicator goes into loop. counts from 0, not from 1.

while loop

iterates until a condition is met. connect an array to the index, and connect the output to the stop box. The loop will stop if the condition is true.

coercion dots

labview converted one data type to a different data type (if they must be of the same data type for example) shown on block diagram INCREASES memory usage (they are bad, so eliminating them can improve program performance, optimize memory usage, and improve accuracy)

highlight execution mode

lightbulb. traces process.

dimension

like 1-D, 2-D, or 3-D + how many layers

concatenate

link together in a chain or series

constants

may be numeric or string

rank

number of dimensions

size

number of elements an array

extent

number of elements in a dimension

elements

numbers contained within dimensions

notifier vs queue

one is used for "one-to-many" communication one is used for "many-to-one" communication

array

ordered sequence of data. vectors, matrices. numbers or strings.

indicator

output (LABview)

breakpoint

pause. view, tools palette, symbolized by red O. put on formula or algorithm to visualize logic.

control references

placed on block diagram for the "calling" or existing VI

rectangle

process information (flowchart)

graph or plot

receives array of data and plots it over time, cannot plot single point value, no updating with time

control palette

right click, expand, and modern tab to get to inputs, outputs, etc. in front.

functions palette

right click, expand, and programming tab to get numerics, operations, strings, constants, etc. in block.

File I/O

saves a file to re-use data, record, or use in another program open/create, write, and close functions

semaphore

send message by signals

string

sequence of letters for constants or labels

Error List

shows: items with errors error and warnings details about warnings

function

subVI. can insert into a main VI

refnum

temporary pointer to an open object

transform array to text function

to specify what's written on a file, wire to output array, and the output of this function will be wired to write to the file box

chart

updates periodically, maintains history of data

help tab

will give a context help and explanation when scrolled over. helpful to write a description for each of your variables or functions to keep track of what's going on

invoke node

will initialize all front panel objects to their default values

application reference

will not change anything on front panel allows program to identify an application for an action

trace table

written representation for every step in a loop