General operation
The most important functions for everyday work are located on the surface. The status bar is at the top of the screen, with the function keys below.

Status bar
The main menu button is located on the far left of the status bar. The area you are currently in is displayed next to it. By default, this is the Register interface.
The currently logged-in user is displayed in the middle of the status bar. On the right is the primasello logo and the Help button, which opens the Help window.

Main menu
The main menu contains extra options for editing master data, system security, and the electronic journal. The functions of these menu items are explained in the subsequent chapters and in the Programming section.
When the main menu is open, the main menu button changes function to display a "Back" arrow. Pressing this arrow closes the main menu and returns you to the Register interface.

The main menu cannot be opened if there are items in the shopping cart. The open document must first be either completed or cancelled.
The following section provides an overview of the main menu's most important buttons and their functions.
Missing functions
Some menu items require special permissions or additional licences. If the buttons in the main menu are invisible or cannot be opened, this means that the corresponding permission or licence is missing.
Billing
Clicking on the orange "Register" button will close the main menu and take you back to the registration interface.

Change PIN
If a PIN has been stored for the logged-in user, it can be changed by pressing the "Change PIN" button. Alternatively, if available, the "Change PIN" button on the receipt interface can be pressed.
Reload
Pressing the "Reload" button refreshes the primasello cash register. This logs out the current user.

Device
The "Device" menu contains detailed information about the cash register, including the model and serial number, the current software version and licence management for additional modules.

Shutdown
You can use the shutdown action to turn off the device.
Note
This function is only available with the primasello A series.

Help
After pressing the Help button, a window opens containing explanations of the most important functions and operating instructions. Clicking on the desired topic on the left-hand side will display the corresponding explanations and instructions in the right-hand section.
Pressing the "More" button at the top of the window displays a QR code that leads to the online user manual.

Receipt interface / Function keys
The function keys are located on the receipt interface, below the status bar. Their functions are explained in the following chapters.

Inactive or non-clickable function keys are displayed in grey. This may be because the function is unavailable in a particular mode, or because authorisation is required.

Keys not found
Function keys can be placed anywhere on the interface or in menu windows, and their names can be changed at any time. If you cannot find the keys described in this documentation, the cash register programmer can provide information about the relevant function key.
You may also find it helpful to consult the quick reference guide for the device, as the names in it are adapted to its specific programming.
Error messages
An error may be triggered by incorrect operation, incorrect input, or pressing the wrong sequence of keys. If an operating error occurs, a warning tone will sound and an error message will appear on the interface. This window explains what caused the error. You can close the error message by pressing the "OK" button.

Data errors may also occur that are not caused by incorrect entries. These errors trigger an error message containing more information. The individual chapters list possible error messages and solutions for each topic.