A short memo to write down how to disable the Device user login.
Here is the link for the device user login:
https://help.codesys.com/api-content/2/codesys/3.5.13.0/en/_cds_handling_user_management_on_plc/
Go to Device>change Communication Policy.
The below screen is shown.
Current Policy>choose optional user management.
Login>Done!
