Introduction to LabVIEW 8.5 Elec 163 Electronic Design I Freshman design course at Wentworth Institute of Technology Original slides prepared by Professor Xiaobin Le of Mechanical program Adapted for Electrical program by Cap’n Tim Johnson, PE

GRAPHICAL PROGRAMMING FOR ENGINEERS AND SCIENTISTS Introduction to LabVIEW GRAPHICAL PROGRAMMING FOR ENGINEERS AND SCIENTISTS © National Instruments Corporation 1 Introduction to LabVIEW Hands-On

Introduction to LabVIEW (1) What is LabVIEW? LabVIEW The Virtual Instrumentation (VI) Approach for measurement systems LabVIEW environment Three parts of a VI Three palettes Show context help Status bar

What is LabVIEW? LabVIEW - Laboratory Virtual Instrument Engineering Workbench LabVIEW is a software, which uses graphical programming language for data acquisition, data analysis, presentation of result and instrument control.

LabVIEW program is called virtual instrument (VI), because their appearance and operation imitate physical instruments, such as oscilloscopes and multimeters

The VI approach for measurement systems High-Speed Digitizers High-Resolution Digitizers and DMMs Multifunction Data Acquisition Dynamic Signal Acquisition Digital I/O Instrument Control Counter/ Timers Machine Vision Motion Distributed I/O and Embedded Control Laptop PC PDA Desktop PC PXI Modular Instrumentation Signal Conditioning and Switching Unit Under Test LabVIEW + Computer Hardware + sensor Object being tested Introduction to LabVIEW Hands-On 6 ni.com

LabVIEW environment LabVIEW provides an easy-to-use graphical programming environment, including all of the tools necessary for data acquisition (DAQ), data analysis and presentation of results. LabVIEW tries to make your life as hassle-free as possible. It has extensive libraries of functions and subroutines to help you with most programming tasks. Three parts of a VI Front panel Block diagram Icon and connector pane Three palettes Tools palette The Controls palette The Functions palette Show context Help Status bar

Three parts of a VI A VI contains the following three components: Front panel—Serves as the user interface for input and show results for output and presentation. Block diagram—Contains the graphical source code that defines the functionality of the VI. (It is a executable program.). It is similar to circuits Icon and connector pane—Identifies the VI so that you can use the VI in another VI. Actually every graphic icon is a kind of sub-VI. It can execute a simple or complicated task and with input and output terminals.

Front Panel The front panel is the user interface of the VI. A front panel contains controls for input and indicators for output or data presentation Controls are knobs, pushbuttons, dials, and other input devices. Controls simulate instrument input devices and supply data to the block diagram of the VI. Indicators are graphs, LEDs, and other displays. Indicators simulate instrument output devices and display data the block diagram acquires or generates.

A VI’s Front Panel Front Panel Controls = Inputs Indicators = Outputs Toolbar Graph Legend Boolean Control Waveform Icon Plot Scale

Block diagram A virtual circuit in which virtual components are wired together A executable graphical program Accompanying “program” for front panel

A VI’s Block Diagram Wire Data Graph Terminal SubVI While Loop Structure Block Diagram Toolbar Divide Function Numeric Constant Timing Boolean Control Terminal

Icon and connector pane Icon and connector pane—Identifies the VI so that you can use the VI in another VI. A VI within another VI is called a sub-VI. Provide the connectors for wiring

Three LabVIEW Palettes The Tools palette is available on the front panel and the block diagram. A tool is a special operating mode of the mouse cursor. The Controls palette is available only on the front panel. The Controls palette contains the controls and indicators you use to create the front panel. The Functions palette is available only on the block diagram. The Functions palette contains the VIs and functions you use to build the block diagram.

Automatic Selection Tool Tools Palette The Tools palette is available on the front panel and the block diagram. A tool is a special operating mode of the mouse cursor. Select View»Show Tools Palette to display the Tools palette. Floating Palette Used to operate and modify front panel and block diagram objects. Automatic Selection Tool Operating Tool Positioning/Resizing Tool Labeling Tool Wiring Tool Shortcut Menu Tool Scrolling Tool Breakpoint Tool Probe Tool Color Copy Tool Coloring Tool

The Controls palette Select View»Show Controls Palette or right-click the front panel workspace to display the Controls palette In the front panel mode, right click any empty place, the “control palette” will be shown. After you choose proper screen, you can pin that screen.

Functions Palette Select View»Show Functions Palette or right-click the block diagram workspace to display the Functions palette. In the Block diagram mode, right click any empty place, the “function palette” will be shown. After you choose proper screen, you can pin that screen.

Show context Help When you point at any icon (graphical code), the description of the icon will be shown if the “show context help” is checked.

Status Toolbar Additional Buttons on the Diagram Toolbar Run Button Continuous Run Button Abort Execution Additional Buttons on the Diagram Toolbar Click the Run button to run the VI. While the VI runs, the Run button appears with a black arrow if the VI is a top-level VI, meaning it has no callers and therefore is not a subVI. Click the Continuous Run button to run the VI until you abort or pause it. You also can click the button again to disable continuous running. While the VI runs, the Abort Execution button appears. Click this button to stop the VI immediately. Note: Avoid using the Abort Execution button to stop a VI. Either let the VI complete its data flow or design a method to stop the VI programmatically. By doing so, the VI is at a known state. For example, place a button on the front panel that stops the VI when you click it. Click the Pause button to pause a running VI. When you click the Pause button, LabVIEW highlights on the block diagram the location where you paused execution. Click the Pause button again to continue running the VI. Select the Text Settings pull-down menu to change the font settings for the VI, including size, style, and color. Select the Align Objects pull-down menu to align objects along axes, including vertical, top edge, left, and so on. Select the Distribute Objects pull-down menu to space objects evenly, including gaps, compression, and so on. Select the Resize Objects pull-down menu to change the width and height of front panel objects. Execution Highlighting Button Retain Wire Values Button Step Function Buttons Introduction to LabVIEW Hands-On 22 ni.com

End of Overview The next few slides will help you get started making your own virtual instrument.

Open LabVIEW

Lab instructions Read Ch1 in “Getting Started with LabVIEW. If your instructor hands out the pages for this chapter you won’t need to open up the manual (instructions follow) This manual is found (on my machine) at C:\Program Files\National Instruments\LabVIEW 8.2\manuals or 2 selections down from where you clicked to start LabView. Click on LV_Getting_Started.pdf to open the manual. Do NOT print out the manual!!!! If you are working as a team have one of your team mates open up the PDF and use that as your copy.

Tutorial As you read through the chapter make the VI and modifications suggested. Turn in a screen print of the design, and Answer the questions on the following page.

Begin designing You are on your way. This lab is part of the design process steps Gathering Information and Conceptualizing Alternate Solutions. The question you are considering is: Will this software help me with the soldering iron project? If so, how?