GF82.85-P-0003SKJ Cockpit Management and Data System (COMAND), Function

GF82.85-P-0003SKJ Cockpit Management And Data System (COMAND), Function
- with CODE (498) Japan version

Component Identification:

Function
The COMAND operating, display and controller unit (A40/3) is the central operating unit for the entertainment and communication systems integrated in the vehicle within the Media Oriented System Transport (MOST). All the system components and controls units involved can be selected and operated via the COMAND operating, display and controller unit (A40/3) and in addition via the control buttons of the multifunction steering wheel (MFL). The COMAND operating, display and controller unit (A40/3) has a video-capable liquid crystal (LCD) color display for the output of information such as operating menu, map data for navigation, TV and video picture. The COMAND operating, display and controller unit (A40/3) can be operated via 3 main control fields, which are located on the left and right next to the screen as well as below it, via a cross-shaped rocker button and a rotary switch.

Controls are:
^ Permanently programmed function keys
^ Alphanumeric key block
^ Programmable function keys
^ Rotary switch with integral ON button
^ Direction input element with OK button
^ Voice repeat button for navigation
^ Mute button

Part of the controls are assigned with fixed functions, i.e. irrespective of the screen applied in each case they always trigger the same response. Several functions can be activated with the aid of the multifunction steering wheel buttons. However, these button operations are initially processed by the instrument cluster (A1). The instrument cluster (A1) links the incoming button actuations with the current menu setting on the upper multifunction display (A1p13) and the lower multifunction display (A1p15).

If necessary, it transmits a corresponding Controller Area Network (data bus/CAN bus) (CAN) message via the audio gateway control unit (N93/1) to the COMAND operating, display and controller unit (A40/3). Depending on the equipment installed, the following functions at most can be operated centrally:
^ Radio mode
^ CD play mode
^ Navigation mode
^ Telematics (telephone, SMS, WAP)
^ Voice control
^ TV mode
^ DVD video
^ Audio AUX

Additional audio sources, e.g. an MP3 player, can be integrated into the front entertainment system using the audio AUX function. An AUX jack is located in the glove compartment as a connection facility.

System components of the COMAND operating, display and controller unit (A40/3) involved:
^ CD player with changer (in glove box) (A2/6) (with code (819) 6-disk CD changer)
^ Hands-free system control unit (A35/1)
^ Audio gateway control unit (N93/1)
^ Multifunction steering wheel (MFL)
^ Instrument cluster (A1)

MOST data bus system
The digital components of the COMAND operating, display and controller unit (A40/3) are interlinked through the MOST data bus system. The databus system is used to transmit data (control commands and useful information) between the various system components. The actual audio signals (e.g. music from CD player with changer (in the glove compartment) (A2/6)) can also be transferred in this way.

Because some of the individual components work with different data formats or require different data transfer rates and security levels, different data bus systems have been installed. Data bus systems:
^ MOST
^ Controller Area Network bus, class B (interior compartment) (CAN B)
^ Controller Area Network bus, class C (engine compartment) (CAN C)

Via the MOST data bus system, data and signals are exchanged between the audio gateway control unit (N93/1), the COMAND operating, display and controller unit (A40/3), the CD player with changer (in glove compartment) (A2/6) (with code (819) 6-disk CD changer) and the hands-free system control unit (A35/1). The COMAND operating, display and controller unit (A40/3) communicates with other system components via the integrated MOST interface.

Interfaces
The CAN-B is used for data exchange with the instrument cluster (A1). In this way, the instrument cluster (A1) receives, from the COMAND operating, display and controller unit (A40/3) via the audio gateway control unit (N93/1), the audio, telephone and navigation data for the upper multifunction display (A1p13) in the instrument cluster (A1) and the time via CAN-B.
Time synchronization between the COMAND operating, display and controller unit (A40/3) and the instrument cluster (A1) can also be performed via the multifunction steering wheel (MFL). To receive data for position finding, the CAN-C is linked to the CAN-B via the central gateway control unit (N93). The data read in by the ESP and BAS control unit (N47-5) are placed on CAN-C and are available on CAN-B via the interface of the central gateway control unit (N93) and thus also to the navigation processor of the COMAND operating, display and controller unit (A40/3) over the audio gateway control unit (N93/1) as an interface via MOST.