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

GF82.85-P-0003TM Cockpit Management And Data System (COMAND), Function
- with CODE (527) COMAND APS with single DVD drive (with navigation)
- with CODE (530) COMAND APS USA (with navigation system)

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 MOST (Media Oriented System Transport). All the system components and control units involved can be selected and operated via the COMAND operating, display and controller unit and additionally via the left multifunction steering wheel button group (S110) and the right multifunction steering wheel button group (S111). The COMAND operating, display and controller unit has a video-capable LCD color display for the output of information such as operating menu, map data for navigation and video image. The DVD video function with code (494) USA version is only permissible for the rear display. The interface is faded out on vehicles without rear display.

The COMAND operating, display and controller unit can be operated via 3 main control panels which are located on the left and right next to the screen as well as below it, via a cross-shaped rocker button (cursor, enter) and via a rotary switch (volume, ON/ OFF).
Controls for the COMAND operating, display and controller unit 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
^ Remote control

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. Some functions can be activated using the left multifunction steering wheel button group and the right multifunction steering wheel button group. However, these button operations are initially processed by the instrument cluster (A1).
The instrument cluster links the incoming button operations with the current menu setting on the multifunction display (A1p13). If necessary, it transmits a corresponding Controller Area Network bus class B (interior) (CAN-B) message via the audio gateway control unit (N93/1) to the COMAND operating, display and controller unit.

The following functions can be operated centrally:
^ Radio mode
^ CD player mode
^ Navigation mode
^ Telephone mode
^ Voice control system (VCS [SBS])
^ External audio devices via AUX connection
^ Video mode

Participating system components of the COMAND operating, display and controller unit with full equipment:
^ Audio gateway control unit (includes radio receiver, CAN-B interface, MOST interface, radio amplifier and audio processor)
^ Universal Portable CTEL Interface (UPCI [UHI]) control unit (N123/1) with code (530) COMAND APS USA (with navigation system)
^ Navigation processor (N41/1)
^ Voice control system control unit (A35/11)
^ CD changer (A2/6)
^ Multifunction steering wheel (MFL)
^ Instrument cluster
^ TV combination tuner (analog/digital) (A90/1) with code (527) COMAND APS with single DVD drive (with navigation)

MOST
The digital components and the COMAND operating, display and controller unit are interlinked via MOST. The MOST is used to transmit data (control commands and useful information) between the different system components.

In the process both control data and the actual audio signals are transmitted (music from CD changer, voice when phoning). As some of the individual components work with different data formats and require different data exchange rates and security levels, different data bus systems have been installed.
Data bus systems:
^ MOST
^ CAN B
^ Controller Area Network bus, class C (engine compartment) (CAN C)

Data or signals are exchanged via the MOST between the audio gateway control unit, the COMAND operating, display and controller unit, the CD changer, the Universal Portable CTEL Interface (UPCI [UHI]) control unit and the voice control system control unit.

In the process both control data and the actual audio signals are transmitted (music from CD changer, voice when phoning). The COMAND operating, display and controller unit communicates with the audio gateway control unit and the other system components via the integrated MOST interface.

Interfaces
The CAN-B is used for data exchange with the instrument cluster. The instrument clusters receives the audio, telephone and navigation data for the multifunction display in the instrument cluster as well as the time from the COMAND operating, display and controller unit via the audio gateway control unit.

Time synchronization between the COMAND operating, display and controller unit and the instrument cluster can also be performed via the 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 control unit (N47-5) are placed on the CAN-C and are available via the central gateway control unit on the CAN-B and thus also via the audio gateway control unit on the MOST and thus to the navigation processor.