Connexions

You are here: Home » Content » File Writer VI
Content Actions
Lenses

What is a lens?

Lenses

A lens is a custom view of Connexions content. You can think of it as a fancy kind of list that will let you see Connexions through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to Connexions materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual Connexions member, a community, or a respected organization.

This content is ...
Affiliated with (?)
This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.

  • This module is included in aLens by: National InstrumentsAs a part of collection:"LabVIEW Graphical Programming Course"

    Comments:

    "A full introductory course on programming with LabVIEW."

    Click the "National Instruments" link to see all content affiliated with them.

    National Instruments
Also in these lenses

  • This module is included inLens: Connexions Books Available for Print on Demand
    By: ConnexionsAs a part of collection:"LabVIEW Graphical Programming Course"

    Comments:

    "This book is available through the Connexions beta version of print-on-demand from online materials."

    Click the "Printable Books" link to see all content selected in this lens.

    Printable Books
Tags

(?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

File Writer VI

Module by: National Instruments

Summary: In this exercise, the objective is to write data to a file. Complete the following steps to build a VI that concatenates a message string, a numeric value, and a unit string to a file. In another exercise, you will build a VI that reads the file and displays its contents.

Problem 1

1.a) Front Panel

  1. Open a blank VI and build the front panel shown in Figure 1.
    filewriter.png
    Figure 1
    1. Place a path indicator located on the Controls>>Text Indicators palette on the front panel. This indicator displays the path for the data file you create.
    2. Right-click the String to Write control and select Visible Items>>Scrollbar from the shortcut menu to display a scrollbar.

1.b) Block Diagram

  1. Build the block diagram shown in Figure 2.
    filewriterbd.png
    Figure 2
    1. buildstringicon.png Place the Create String VI from the previous exercise on the block diagram. Select Functions>>All Functions>>Select a VI and navigate to C:\Exercises\LabVIEW Basics I\Create String.vi. This subVI concatenates the three input strings to one combined string.
    2. OpenFileIcon.png Place the Open/Create/Replace File VI, located on the Functions>>All Functions>>File I/O palette, on the block diagram. This VI displays a dialog box to open or create a file. Right-click the prompt input, select Create>>Constant from the shortcut menu, and type Enter Filename in the constant. When the VI runs, a file navigation dialog box appears with Enter Filename as the title of the window. Right-click the function input, select Create>>Constant from the shortcut menu, and click the constant with the Operating tool to select create or replace.
    3. WriteFileIcon.png Place the Write File function, located on the Functions>>All Functions>>File I/O palette, on the block diagram. This function writes the concatenated strings to the file.
    4. CloseFileIcon.png Place the Close File function, located on the Functions>>All Functions>>File I/O palette, on the block diagram. This function closes the file.
    5. Error.png Place the Simple Error Handler VI, located on the Functions>>All Functions>>Time & Dialog palette, on the block diagram. This function checks the error cluster and displays a dialog box if an error occurs.
    6. Complete the block diagram as shown in Figure 2.
  2. Save the VI as File Writer.vi in the C:\Exercises\LabVIEW Basics I directory.

1.c) Run the VI

  1. Enter values in the front panel controls and run the VI. An Enter Filename dialog box appears.
  2. Type demofile.txt and click the Save or OK button to save the file. The VI writes the String to Write, Numeric to Write, and Unit to Write values to the file.
  3. Close the VI.

Comments, questions, feedback, criticisms?

Discussion forum

Send feedback