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

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

Component Identification:

Function
The COMAND operating, display and controller unit 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 can be selected and operated via the COMAND operating, display and controller unit and in addition via the left multifunction steering wheel button group and right multifunction steering wheel button group. The COMAND operating, display and controller unit has a video-compatible LCD (liquid crystal display) color display for displaying information such as the operating menu, map data for the navigation and video image (with code (527) COMAND APS with single DVD drive (with navigation))

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, a cross-shaped rocker button (cursor, enter) and a rotary switch (volume, ON/OFF).
Controls for the COMAND operating, display and controller unit are:
^ Fixed 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. Some functions can be activated using the left multifunction steering wheel button group and the right multifunction steering wheel button group. However, these button actuations are first reconditioned by the instrument cluster.
The instrument cluster links the incoming button actuations to the current menu setting on the multifunction display (A1p13). Where appropriate, it sends a corresponding Controller Area Network bus Class B (interior) (CAN-B) message to the COMAND operating, display and controller unit via the audio gateway control unit. The following functions can be operated centrally:
^ Radio mode
^ CD player mode
^ Navigation mode
^ Telephone mode
^ Voice control
^ External audio devices via AUX connection
^ Video mode, with code (527) COMAND APS with single DVD drive (with navigation system)

Participating system components of the COMAND operating, display and controller unit with full equipment:
^ Audio gateway control unit (includes radio receiver, radio amplifier, CAN-B interface, MOST interface and audio processor)
^ Universal Portable CTEL Interface (UPCI [UHI]) control unit (telephone, SMS)
^ Emergency call system control unit (N123/4), with code (530) COMAND APS USA (with navigation system)
^ Navigation processor
^ Voice control system (VCS [SBS]) control unit
^ CD changer
^ Multifunction steering wheel (MFL)
^ Instrument cluster
^ TV combination tuner (analog/digital) (A90/1), with code (527) COMAND APS with single DVD drive (with navigation system)

MOST
The digital components in the COMAND operating, display and controller unit are interlinked through MOST. MOST is used to transmit data (control commands and useful information) between the various system components. In the process both control data and the actual audio signals are transmitted (music from CD changer, voice when phoning).
Different data bus systems are installed as to some extent different data formats are used for individual components or different requirements are placed on bit rate and security. Data bus systems:
^ MOST
^ CAN-B
^ Controller Area Network bus, Class C (engine compartment) (CAN C)

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

Interfaces
The CAN-B is used for data exchange with the instrument cluster. This is how the instrument cluster 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 multifunction steering wheel.
In order to receive data for position finding, the CAN-C is linked to the CAN-B via the central gateway control unit.

The data read in from the ESP control unit are placed on the CAN-C and are available on the CAN-B via the central gateway control unit and are therefore available to the navigation computer as well as the MOST via the audio gateway control unit.