Starting with the CODESYS 3.5.17.0 runtime (as included in EPIC 3.3.0 firmware), Device User Management is now “enforced by default”. While these features are not new, they are now the default behavior. To be clear, this is the new runtime, not the desktop Development System (IDE).
When first connecting to a PLC with 3.5.17.0 or later, the user is now presented with this message.
Then they must configured a user with a password:
Then when going Online, they must enter admin credentials:
The controller does remember you, so within the same session, you can go back and forth between Online and Offline mode.
The active user can be logged off with Online → Security → Logoff Current Device User .