What to Use
What to Do
Create the following diagram to programmatically open, write to, and close a text file.
Customize the gray sections for your unique programming goals.
|
Open, create, or replace a file by using the Open/Create/Replace File node and specifying its precise behavior. To access the enumerated list of possible behaviors, create a constant from the operation input of the node. |
|
After the file opens, a unique identifier called a refnum represents the file. A file refnum is required for most nodes that process files. |
|
Process the file by using a file I/O node from the File I/O palette category. You can interact with binary or text files. In this example, Write to Text File writes Hello world to the file represented by the file refnum. |
|
Close the file to release the object from memory and avoid potential errors. If you do not close a file, LabVIEW cannot close the reference until the VI that opened the file finishes executing. |
Troubleshooting
-
Some file I/O nodes are considered high-level nodes and perform all three steps of a file I/O process—open, read/write, and close. Avoid placing high-level file I/O nodes, such as Read from Spreadsheet File and Write to Spreadsheet File, in loops because these nodes perform open and close operations each time they run.