Cockpit management and data system (COMAND), function - GF82.85-P-0003QM: Notes

MODEL 209.3 /4 as of 1.6.04 with CODE (527) COMAND APS (with navigation) 

Fig 1: Cockpit Management And Data System (COMAND) Function Diagram - 209 COMAND APS (With Navigation)

The COMAND operating, display and controller unit (A40/3) can be used to operate the following systems centrally:

• Integrated radio
• Integrated CD disk drive
• Navigation with dynamic destination-oriented navigation system
• Dynamic destination-oriented navigation system in Germany
• CD changer (with code (819) 6-disk CD changer)
• Portable cellular telephone (with code (388) Telephone "Handy", UPCI system)
• Sound system (with code (810) Sound system)
• Voice control system (VCS [SBS]) (with code (813) Voice control system (VCS [SBS]))
• External devices (e.g. an MP3 player) via AUX jack (in glove box)

The COMAND operating, display and controller unit (A40/3) is the central Cockpit Management and Data Systems (COMAND) component. It contains a video-capable display for showing information such as operating menus or map data for the navigation. It is operated by means of preset function keys and 2 rotary switches as well as menu-assisted on the display. Some functions can also be activated via the multifunction steering wheel (MFL). Here one should note that all actuations on the multifunction steering wheel are initially processed by the instrument cluster (A1). The instrument cluster (A1) links the incoming button actuations with the current menu setting in the multifunction display (A1p13) and, where applicable, it then transmits a message to the COMAND operating, display and controller unit (A40/3).

Data bus systems 

The digital components in COMAND are linked to each other. The data bus system is used to transmit data (control commands and useful information) between the various components.

The individual component operate with various data formats and they have different request in terms of transmission rate and reliability. Therefore, the following data bus systems are installed:

• Media Oriented System Transport (MOST) Data are exchanged between the sound amplifier (A2/13), the CD player with changer (in glove box) (A2/6), the telephone system and, if fitted, the voice control system control unit (A35/11). Both control data as well as the audio signals are transmitted.
• Controller area network bus class B (interior compartment) (CAN B)

The CAN-B is used for data exchange with the instrument cluster (A1). In this way, the instrument cluster (A1) receives the audio, telephone, and navigation data for the multifunction display (A1p13) in the instrument cluster (A1) from the COMAND operating, display and controller unit (A40/3) as well as the time via this data bus.

Additional audio sources (e.g. MP3 player, Walkman) can be connected using the "Audio-AUX" function. For this purpose, an AUX bushing is located in the glove compartment as connection facility.