The Bosch PRA-APAL is a license code for an operator device to access the advanced public address server PRA-APAS for PRAESENSA. It adds advanced business related public address functions to the function set provided by the system controller. A PC or wireless tablet, connected to the local IP-network, functions as operator device with an intuitive graphical user interface, controlled by mouse or touch screen. A headset, connected via USB or Bluetooth to the operator device, may be used for voice announcements and audio monitoring. The integrated device platform independent. Each operator device uses its own web browser as operator interface (Chrome preferred).