This document provides an introduction to LabVIEW, a graphical programming language from National Instruments. It discusses that LabVIEW uses graphical symbols and dataflow programming rather than text, and is suited for people who need programming but not a programmer. The basics of LabVIEW are explained, including that programs are called VIs, and consist of a front panel, block diagram, and connector panel. Common programming elements like loops, controls, and indicators are also overviewed.
5. TEXT / GRAPHICAL PROGRAMMING LANGUAGE
• INT A
• INT B
• INT SUM
(INT A, INT B);
6. ABOUT LABVIEW
• LabVIEW IS A HIGHLY ADAPTABLE PROGRAMMING GUI (GRAPHIC
USER INTERFACE)
• LabVIEW COMPILES THE CODE INTO MACHINE INSTRUCTIONS,
MUCH LIKE THE PROGRAMMING LANGUAGE C
• THIS LANGUAGE (G) IS USED EXTENSIVELY THROUGHOUT A WIDE
VARIETY OF INDUSTRIES.
7. GRAPHICAL PROGRAMMING LANGUAGE & DATA
FLOW
• LABVIEW RELIES ON GRAPHICAL SYMBOLS RATHER THAN
TEXTUAL LANGUAGE TO DESCRIBE PROGRAMMING ACTIONS
• THE PRINCIPLE OF DATAFLOW, IN WHICH FUNCTIONS EXECUTE
ONLY AFTER RECEIVING THE NECESSARY DATA, GOVERNS
EXECUTION IN A STRAIGHT FORWARD MANNER
8. BASICS TERMS TO KNOW
• FRONT PANEL
• BLOCK DIAGRAM
• CONNECTOR PANEL
• VI
• WIRES
• BASIC COLOUR
• BROKEN WIRE
9. FRONT PANEL
• THE FRONT PANEL OF EACH VI IS WHERE YOU WILL
ACTUALLY USE THE PROGRAM.
• THIS IS WHERE YOU PLACE ALL OF YOUR
CONTROLLERS (THEY ALLOW YOU TO SET A VALUE),
INDICATORS (THEY SHOW YOU THE RESULT VALUE ),
10. BLOCK DIAGRAM
• THE BLOCK DIAGRAM IS WHERE YOU WRITE YOUR ACTUAL
CODE.
• USE WIRES TO CONNECT DIFFERENT INPUTS, OUTPUTS,
FUNCTIONS, AND VALUES.
• ALL OF THE CODE RUNS PARALLEL, WHICH MEANS THAT IT
FOLLOWS THE WIRE LEFT TO RIGHT.
11. CONNECTOR PANEL
• THE CONNECTOR PANEL ALLOWS YOU TO TURN A VI INTO
A FUNCTION.
• THIS MAKES IT EASY TO SIMPLIFY CODE.
• THE CONNECTOR PANEL HAS A PICTURE THAT YOU MAKE
OF THE CODE TO REPRESENT THE FUNCTION.
• YOU CAN THEN ADD TERMINALS TO THE PICTURE TO
ALLOW YOU TO WIRE PARTS OF THE CODE TO OTHER
VIS.
12. BRING THE VI COMPONENTS
TOGETHER
Block diagram
Front Panel
Connector Panel
+ =
13. MATH EXAMPLE- THE QUADRATIC EQUATION
As you can see,
math isn’t too
hard to program in
LabView. Just
make sure to pay
attention to the
places where a
wire crosses
another wire,
because those
jumps can cause
some confusion.
I branch several wires to stop the program from
having to do the same thing twice. This is more
to make it read easier than anything, but it may
save several computer cycles in complex code.
14. HOW DOES LABVIEW WORK?
• LABVIEW PROGRAMS ARE CALLED:
• VIRTUAL INSTRUMENTS (VIS)
• BECAUSE THEIR APPEARANCE AND OPERATION IMITATE
ACTUAL INSTRUMENTS.
• HOWEVER, THEY ARE ANALOGOUS TO MAIN
PROGRAMS, FUNCTIONS AND SUBROUTINES
FROM POPULAR LANGUAGE LIKE C, FORTRAN,
PASCAL, …
16. LOOPS
• FOR LOOP
• 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
16
18. THE RUN BUTTON
THE RUN BUTTON, WHICH
LOOKS LIKE AN ARROW,
STARTS VI EXECUTION
WHEN YOU CLICK ON IT
IT CHANGES APPEARANCE
WHEN A VI IS ACTUALLY
RUNNING.
WHEN A VI WON’T COMPILE,
THE RUN BUTTON IS
BROKEN
19. RUNNING LABVIEW PROGRAMS
• ALMOST ALWAYS PUT YOUR PROGRAM IN SOME SORT OF
LOOP THAT CAN BE STOPPED WITH A CONTROL
• AVOID USING THE RED “X” TO STOP YOUR PROGRAM