Note: Your browser may not currently support MathML. See our browser support page for additional details. You can always view the correct math in the PDF version.
After you build a VI front panel and block diagram, build the icon and the connector pane so you can use the VI as a subVI.
Every VI
displays an icon, shown in Media 1, in the upper
right corner of the front panel and block diagram windows. An
icon is a graphical representation of a VI. It can contain
text, images, or a combination of both. If you use a VI as a
subVI, the icon identifies the subVI on the block diagram of
the VI.
The default icon contains a number that indicates how many new
VIs you have opened since launching LabVIEW. Create custom
icons to replace the default icon by right-clicking the icon
in the upper right corner of the front panel or block diagram
and selecting Edit Icon from the shortcut menu or
double-clicking the icon in the upper right corner of the
front panel. You also can edit icons by selecting
File>>VI Properties selecting General
from the Category pull-down menu, and clicking
the Edit Icon button.
Use the tools on the left side of the Icon Editor
dialog box to create the icon design in the editing
area. The normal size image of the icon appears in the
appropriate box to the right of the editing area, as shown in
the dialog box in Figure 1.
Depending on the type of monitor you use, you can design a separate icon for monochrome, 16-color, and 256-color mode. LabVIEW uses the monochrome icon for printing unless you have a color printer.
Use the Edit menu to cut, copy, and paste
images from and to the icon. When you select a portion of the
icon and paste an image, LabVIEW resizes the image to fit into
the selection area. You also can drag a graphic from anywhere
in your file system and drop it in the upper right corner of
the front panel or block diagram. LabVIEW converts the graphic
to a
Use the Copy from option on the right side of
the Icon Editor dialog box to copy from a color
icon to a black-and-white icon and vice versa. After you
select a Copy from option, click the OK
button to complete the change.
Use the tools on the left side of the Icon Editor
dialog box to create the icon design in the editing
area. The normal size image of the icon appears in the
appropriate box to the right of the editing area. The
following tasks can be performed with these tools:
Use the
Pencil tool to draw and erase pixel by pixel.
Use the
Line tool to draw straight lines. To draw
horizontal, vertical, and diagonal lines, press the
<Shift> key while you use this tool to
drag the cursor.
Use the
Color Copy tool to copy the foreground color
from an element in the icon.
Use the
Fill tool to fill an outlined area with the
foreground color.
Use the
Rectangle tool to draw a rectangular border
in the foreground color. Double-click this tool to frame
the icon in the foreground color.
Use the
Filled Rectangle tool to draw a rectangle
with a foreground color frame and filled with the
background color. Double-click this tool to frame the icon
in the foreground color and fill it with the background
color.
Use the
Select tool to select an area of the icon to
cut, copy, move, or make other changes. Double-click this
tool and press the <Delete> key to delete
the entire icon.
Use the
Text tool to enter text into the
icon. Double-click this tool to select a different
font. (Windows) The
Small Fonts option works well in icons.
Use the
Foreground/Background tool to display the
current foreground and background colors. Click each
rectangle to display a color palette from which you can
select new colors.
Icon Editor dialog box
contains more editing options such as Undo, Redo,
Cut, Copy, Paste , and Clear .
To use a
VI as a subVI, you need to build a connector
pane, shown in Media 12. The connector pane
is a set of terminals that corresponds to the controls and
indicators of that VI, similar to the parameter list of a
function call in text-based programming languages. The
connector pane defines the inputs and outputs you can wire to
the VI so you can use it as a subVI.
Define connections by assigning a front panel control or
indicator to each of the connector pane terminals. To define a
connector pane, right-click the icon in the upper right corner
of the front panel window and select Show Connector
from the shortcut menu. The connector pane replaces
the icon. Each rectangle on the connector pane represents a
terminal. Use the rectangles to assign inputs and outputs. The
number of terminals LabVIEW displays on the connector pane
depends on the number of controls and indicators on the front
panel. The following front panel has four controls and one
indicator, so LabVIEW displays four input terminals and one
output terminal on the connector pane.
![]() |
Select a different terminal pattern for a VI by right-clicking
the connector pane and selecting Patterns from
the shortcut menu. Select a connector pane pattern with extra
terminals. You can leave the extra terminals unconnected until
you need them. This flexibility enables you to make changes
with minimal effect on the hierarchy of the VIs. You also can
have more front panel controls or indicators than terminals.
A solid border highlights the pattern currently associated with the icon. The maximum number of terminals available for a subVI is 28.
The most
commonly used pattern is shown in Media 14. This
pattern is used as a standard to assist in simplifying
wiring. The top inputs and outputs are commonly used for
passing references and the bottom inputs and outputs are used
for error handling. Refer to the section on Clusters for more information about error
handling.
To change the spatial arrangement of the connector pane
patterns, right-click the connector pane and select
Flip Horizontal, Flip Vertical, or Rotate 90 Degrees
from the shortcut menu.
After you select a pattern to use for the connector pane, you must define connections by assigning a front panel control or indicator to each of the connector pane terminals. When you link controls and indicators to the connector pane, place inputs on the left and outputs on the right to prevent complicated, unclear wiring patterns in your VIs.
To assign a terminal to a front panel control or indicator, click a terminal of the connector pane, then click the front panel control or indicator you want to assign to that terminal. Click an open space on the front panel. The terminal changes to the data type color of the control to indicate that you connected the terminal.
You also can select the control or indicator first and then select the terminal.
Wiring tool to assign
terminals on the connector pane to front panel controls and
indicators, no wires are drawn between the connector pane and
these controls and indicators.
"A full introductory course on programming with LabVIEW."