OPC UA allows handling files for example as ByteStrings. However, transferring large files becomes an issue due to the maximum message size. It would be desirable to have a standard concept in the information model representing files and allowing reading, writing and manipulating files by accessing the files in several requests so the file is split into several messages and the max. message size does not have to be increased as this would be a security risk (DOS attacks).
This is for example needed in the next version of the PLCopen 61131-3 information model, but also FDI deals with files and there is a general need for example when downloading a new configuration to a PLC.