Use the error ring constant to make error codes and error clusters more descriptive.
The error ring constant includes a predefined list of errors specific to memory usage, networking, printing, and file I/O. Set the error ring constant by using the Operating tool to select the error message you want to include in the Error List window.
For example, if you try to open a nonexistent file using the Open File function, the function returns an error code of 7. You can set up your VI to test for this condition by comparing the numeric error code output to an error ring constant set to a value of File Not Found (7). The VI can then display an error dialog box that contains the File Not Found string instead of the less descriptive numeric error code.