Using the Error Handler in LabVIEW Real-Time

The General Error Handler VI has been changed in LabVIEW 6.1. The correct files are automatically copied to the RT Engine when you install LabVIEW software on the RT engine.

However, if you are using custom errors, there are a few steps you must take to place the files in the correct location. You can create your custom error file by using the Error Code File Editor dialog box located in LabVIEW by selecting Tools»Advanced»Edit Error Codes.


Alternatively, you can create the file directly using a text editor like notepad. The file should have the following format:

<?XML Version="1.0">
<nidocument>
<nicomment>
This file describes errors for the
LabVIEW 6.1 application.
</nicomment>
<nierror code="2">
I am error 2.
</nierror>
<nierror code="3">
I am error 3.
</nierror>
</nidocument>

The files should be placed in C:\NI-RT\SYSTEM\USER.LIB\ERRORS\ on the RT Engine. You will need to create this directory first. To do this, start an ftp session to the engine and use the mkdir command to create the directory.


The error files should be named with a .err extension rather than -errors.txt convention used in regular LabVIEW applications to conform to the 8.3 filename structure. This is a limitation of the RT engine file system.

There are two configuration tokens available for error files. Setting RTDownloadErrors=TRUE in the embedded system's NI-RT.INI file will cause the RT Engine to request a list of available errors the first time it is targeted. This request will only occur if the RT Engine can not find any error files locally, such as an RT Engine that does not have disk I/O (the 7030 target is an example of such an engine). The host machine will search for all available error files, then transfer the parsed error data back to the RT target. If you wish to specify the actual filenames that should be parsed by the host system, you can create a list using the RTDownloadErrorList token in the RT Engine's NI-RT.INI file. The following is an example of an ni-rt.ini file:

[lvrt]
...
RTDownloadErrors=TRUE
RTDownloadErrorList="LabVIEW-errors.txt;Analysis-errors.txt;Measure-errors.txt;NI-DAQ LV-errors.txt"
...

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