The navigation processor (N41/1) is activated by pressing the "NAV" button, the "Eject" button, or by inserting a navigation digital versatile disk (DVD) and supplies all necessary data and information to the COMAND operating, display and control unit (A40/3) during navigation mode. All the calculations for position finding, route calculation, and navigation are performed in the navigation processor (N41/1). The control signals, map data, and voice signals are transmitted via Media Oriented System Transport (MOST).
When a CD or navigation DVD is loaded into the navigation processor (N41/1), only the data medium is accepted. No download is started.
The following information is included on the data medium:
Navigation data basis for location finding, route calculation and navigation
Data for dynamic navigation system
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Data on map presentation
Index data base for destination and location for destination and location input
Expanded data for the journey guide data
Data for the voice output
External information
The audio gateway control unit (N93/1) supplies, as the interface between CAN-B and MOST, the external information to the other MOST components. The following information is required:
Circuit status (e.g., circuit 15R ON, circuit 15 ON)
Wheel revolution and wheel direction of rotation
Diagnostic data
Diagnosis
When the COMAND operating, display and control unit (A40/3) is switched on and during operation, some partial functions and navigation components are monitored.
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Faults that might have occurred are saved in the fault memory and can be read out using STAR DIAGNOSIS.
Destination memory and intermediate destinations
The destination memories, address books, and intermediate destinations are managed in the COMAND operating, display and control unit (A40/3).
Map display
The digital map display is always controlled by the COMAND operating, display and control unit (A40/3).
GPS receiver
The GPS receiver is part of the navigation processor (N41/1). It evaluates the satellite signals coming from the GPS antenna (A2/23) and calculates the vehicle position from this information.