I have a problem with User login.

I am using a WinCC Unified V17 with MTP700 Unified Comfort panel. When i connect to the panel from my PG with browser or starting simulation, every thing fine. WinCC always ask a login and password. But when try to work just with panel - nothing. I download project to panel, runtime starts without any login and variable @UserName stays empty. Adding button with LOGOFF function doesn't helps. If i connect to the panel from my PG with browser or starting simulation - it work's like it should. But pressing this button on panel - does nothing. I haven't found LOGIN function in WinCC. So i don't now what to try next. 

I can't understand your request.

If you connect from PG to simulation you need to login but if you use only the Panel, the runtime start normally like any other hmi. 

In my project i use a button for login with highest security level (normally administrator)  but without any functions.

Everytime any user, except administrator,  click on this button, hmi request a login.