WebVisualization has a built-in file select dialog that programmers can use to allow an operator to load a file. The FileOpenSave dialog returns strings containing the file name and the absolute path. These can then be used throughout the programmer's IEC program to reference a file that has been selected by the user. A common use case is to provide a reference to a CNC file.
The sample project included in this article contains a visualization that demonstrates the use of the FileOpenSave dialog. It also contains a POU called PLC_PRG that shows how to implement the required initialization and support code.
The sample project can be downloaded using the link below.