Activate login mode:
To activate login mode on the RolloTron Comfort DuoFern, open the menu using the Menu button (M) and use the Plus + or Minus button to select -. System settings. 
Select and open menu 9.9.1.
The display shows the registered DuoFern devices.
Example: 05 = five DuoFern devices are logged in.
Activate the log-in mode by briefly tapping 
the Plus key.
On = Login mode
If the login mode is active, On flashes in the display. The login mode remains active for 120 seconds.
Switch the respective DuoFern device to logon mode.
After successful login, the new number of logged-in devices appears (e.g. 06).
The RolloTron starts up briefly to acknowledge this.
Press the OK button to return to the menu selection. Press and hold the Menu key (M) to exit the menu.
Basic notes:
End point setting:
Without an end point setting, the RolloTron Comfort DuoFern will only run as long as one of the two control buttons is pressed. Without end point setting, the automatic functions remain disabled.
Setting DuoFern mode - DuoFern receiver:
If the RolloTron Comfort DuoFern is registered with a DuoFern control center such as HomePilot®Type 9496-3, DuoFern manual control center Type 9493-1, HomeTimer Type 9498 or another RolloTron Comfort DuoFern type, the DuoFern mode should be changed to receiver on the RolloTron.
The RolloTron Comfort DuoFern also has a complete time program; switching to receiver deactivates the RolloTron Comfort DuoFern's own switching time program.
Menu item 9-9-2 to 1 (receiver)