164 Display and Operational Controls4.1 OperationUsing the arrow keys you can navigate within the menus.In the process, move the keys and to the right or left by one to make a selection.ENTER ENTER takes you to menu entries or to the edit mode in the case of selected pa-rameters or values.With the keys and the currently selected value can be changed accordingly Holddown the respective key and the value will count automatically up or down.BACK BACK leaves the window, menu, or edit mode.4.2 Menu Structure4.2.1 Password Entry Menu StructureWithout access levelCustomer access levelService access level