Mostrando entradas de junio, 2017

Release current directory

This is not mine, it's a tip I found years ago in a LabVIEW forum and still works like a charm (thanks to the genious that got it!).When the user selects a file to work with (signal data you want to analyze, for example) your LabVIEW application "grabs" its path, so you can't delete it or its directory, or unmount the unit if you're using an external drive, even if you are not reading that file anymore and you clear any path controls. But we can use Kernel32.dll method SetCurrentDirectoryA to release it (obviously, this only works in Windows systems).No downloadable code today, it's better if you link the call library function node by yourself, so you're sure it finds the dll. You can find more info about this method here: SetCurrentDirectory function at MSDN.

Variant to XML

Converting to XML format is a good way of exporting data in a standard, human-readable way. I have used it to pass and receive data from other languages, for example, or if you need to dump data to a log file.As you may know, LabVIEW includes its own functions for converting to and from XML, called Flatten To XML and Unflatten From XML. Unfortunately, it's a raw conversion that just gives a node with the data type and two child nodes, name and value. So, to find a field you must recover first all the name nodes, locate the one you need and then find its value sibling. Too crude for a lot of scenarios:So I developed my own library to do this conversion in a more convenient way. Check the differences in the next image:As you can see the field names are now used as tag names, resulting in a shorter and cleaner XML text. The reverse conversion (from XML to LabVIEW data) is shown in the bottom of the image, and works the same.In the block diagram, these functions are used directly, jus…