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File Operation

This section covers how to use the OPC UA File Operation node to read and write files stored on OPC UA servers that implement the FileType interface (ns=0;i=11575).

Overview​

The OPC UA File Operation node enables interaction with files on OPC UA servers, supporting:

  • Reading file contents in various formats (text, binary, line-by-line)
  • Writing and overwriting file data
  • Appending data to existing files
  • Checking file sizes
  • Multiple text encodings (UTF-8, Shift_JIS, GB2312, and more)
  • Automatic handling of large files with chunking

Tutorials​

Quick Reference​

Common Operations​

Read a text file:

  • Mode: Read
  • Format: utf8
  • Encoding: utf8

Write JSON data:

  • Mode: Write
  • Encoding: utf8
  • Payload: JavaScript object (auto-converted to JSON)

Append log entries:

  • Mode: WriteAppend
  • Encoding: utf8
  • Payload: String with \n at the end

Check file size:

  • Mode: ReadSize
  • Output: msg.payload contains size in bytes

See Also​