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

GF82.85-P-0003R Cockpit Management And Data System (COMAND), Function

MODELS 203.0 /2 /7 up to 23.4.04
- with CODE (352a) COMAND operating and display system
- with CODE (491) U.S. version







Block diagram, overall system Illustrated with following equipment:
- CD changer (code 819a)
- Voice control system (VCS) (code 813)
- AMPS-network portable CTEL telephone (D2B)

D2B Digital data bus
ESP Electronic stability program
MFL Multifunction steering wheel
A1 Instrument cluster
A2/6 CD changer (in glove compartment)
A2/13 Sound amplifier
A2/23 GPS antenna
A28/2 Portable CTEL antenna amplifier
A34/4 CTEL interface
A34/6 Portable CTEL
A35/8 E-call control unit
A35/11 Voice control system control unit
A40/3 COMAND operating, display and control unit
B25 Hands-free system microphone
N73 DI control unit
X11/4 Datalink connector

Cockpit management and data system (COMAND), function
The COMAND operating, display and control unit (A40/3) is the central component in the COMAND system. It has a video-capable Liquid Crystal Display (LCD) color display to output information such as operating menus and map data for navigation. It is operated by means of fixed function keys and two rotary controls as well as menu-guided in the display. Several functions can also be activated with the aid of the buttons on the multifunction steering wheel (MFL). It should be noted that all button operations on the multifunction steering wheel (MFL) are first processed by the instrument cluster (A1). The instrument cluster (A1) combines the incoming button signals with the current menu setting on the multifunction display (A1p13) and sends an appropriate Controller Area Network (databus/ CAN bus) (CAN) message to the COMAND operating, display and control unit (A40/3) if necessary.

The vehicle can also be equipped optionally with an infrared remote control for issuing commands from the rear of the passenger compartment as well as a voice control system (VCS) (code 813) for telephone functions and several audio functions, both of which serve to further enhance operating convenience.

Bus system (COMAND)
The digital components in the COMAND operating, display and control unit (A40/3) are networked with each other through a bus system. The bus system is used to transmit data (control commands and useful information) between the various system components. Because some of the individual components work with different data formats or require different data transfer rates and security levels, the following different bus systems have been installed:
- Controller area network bus class B (interior) (CAN-B)
- Digital databus (D2B)

The digital data bus (D2B) is used for data exchange between the sound amplifier (A2/13) (with code 810), the CD player with changer (in glove compartment) (A2/6) (with code 819a), the telephone system and, if installed, the voice control system (VCS) (with code 813). Both control data as well as the actual audio signals are transmitted.

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 control unit (A40/3), the audio, telephone and navigation data for the multifunction display (A1p13) in the instrument cluster (A1) as well as the time of day.