LABVEW NI-TUTORIAL

Tutorial: Front Panel
Overview
This tutorial explores the Front Panel and its relationship with the Block Diagram. Learn about the different types of Front Panel objects as well as how to find them on the Controls palette and place
them on the Front Panel.
This video explores the Front Panel and its relationship with the Block Diagram. Learn about the different types of Front Panel objects as well as how to find them on the Controls palette and place
them on the Front Panel.This video explores the Front Panel and its relationship with the Block Diagram. Learn about the different types of Front Panel objects as well as how to find them on the
Controls palette and place them on the Front Panel.This video explores the Front Panel and its relationship with the Block Diagram. Learn about the different types of Front Panel objects as well as
how to find them on the Controls palette and place them on the Front Panel.
The front panel window is the user interface for the VI. The front panel has controls and indicators, which are the interactive input and output terminals, respectively, of the VI. Controls and
indicators placed on the front panel are automatically placed on the block diagram. Refer to the “Block Diagram” tutorial for more information on block diagram terminals.
Front Panel Window
When you open a new or existing VI, the front panel window of the VI appears and functions as the graphical user interface or GUI of a VI. You can find the source code that runs the front panel on
the block diagram. The front panel window contains a toolbar across the top and a Controls palette that you can access by right-clicking anywhere on the front panel.


After opening the Controls palette, use it to place controls and indicators on the front panel.


Note: Use the thumb tack to pin the Controls palette to the front panel and then select View»Change Visible Categories.

the Change Visible Categories dialog box, click Select All and then OK to make all available controls and indicators visible on the front panel.


Controls and Indicators
Controls – knobs, push buttons, dials, and other input devices – are the interactive input terminals, while indicators — graphs, LEDs, and other displays – are the interactive output terminals of the
VI. Controls simulate instrument input devices and supply data to the block diagram of the VI. Indicators simulate instrument output devices and display data the block diagram acquires or
generates.



The figure above has two controls – Number of Measurements and Delay (sec) – and one indicator, a waveform graph named Temperature Graph. The user can change the input value for the
Number of Measurements and Delay (sec) controls. The user can see the value generated by the VI on the Temperature Graph indicator. The VI generates the values for the indicators based
on the code created on the block diagram. To learn more about the block diagram, see the “Block Diagram” tutorial.
Every control and indicator has a data type associated with it. For example, the Delay (sec) horizontal slide is a numeric data type. Double-click the Delay (sec) control to make LabVIEW jump to the terminal location on the block diagram. Notice the color of the terminal. Orange terminals signify a data type called double (DBL), which is a type of numeric data.

The most commonly used data types are numeric, Boolean value, and string. Learn more about data types in the “Data Types” tutorial.
Numeric Controls and Indicators
The numeric data type can represent various types of numbers, such as integer or real. The two common numeric objects are the numeric control and the numeric indicator. Objects such as meters
and dials also represent numeric data. Use the Controls palette to place a numeric control on the front panel and then use the increment and decrement buttons to adjust its values.
Follow steps 1-3 to create a numeric control and change its value.
1. Right-click the front panel to open the Controls palette, and from the Numeric subpalette drag and drop a Numeric Control onto the front panel.


2. Label the control Input by double-clicking on the label and typing the word “Input.”

3. Now change the value of the control by clicking the increment or decrement button. Alternatively, you can double-click the number with either the Labeling tool or the Operating tool, enter a
new number, and press the <Enter> key.


Boolean Controls and Indicators
The Boolean data type represents data that has only two parts, such as TRUE and FALSE or ON and OFF. Use Boolean controls and indicators to enter and display Boolean values. Boolean objects simulate switches, push buttons, and LEDs. The vertical toggle switch and the round LED Boolean objects are shown below. You can find them in the Boolean subpalette in the Controls
palette (see below).








String Controls and Indicators
The string data type is a sequence of ASCII characters. Use string controls to receive text from the user, such as a password or user name, and use string indicators to display text to the user. The
most common string objects are tables and text entry boxes as shown below. You can find string controls and indicators in the String and Path subpalette or the Lists and Tables subpalette.
Some common string indicators are shown below.

Shortcut Menus and Property Dialog Boxes
All LabVIEW objects have associated shortcut menus and property dialog boxes. As you create a VI, use the shortcut menu items and/or the properties dialog box to change the appearance and/or
behavior of front panel and block diagram objects. To access the shortcut menu, right-click the object you want to modify. To access the Properties dialog box, select Properties from the shortcut
menu.
Follow steps 1 and 2 to create a string control and then use the Properties dialog box to add a scroll bar. Start with a blank VI.
1. From the String & Path subpalette, select a String Control and place it on the front panel.


2. Right-click the string indicator to open the shortcut menu and select Properties.

 3. From the Properties dialog box, put a check in the Show vertical scroll bar checkbox and click OK.

4. The resulting string control has a scroll bar so the user can scroll up and down to view all of the text. This allows the use of a small string control to display a large amount of text.