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

MODEL 215, 220 as of 1.9.03 with CODE (352) COMAND operating and display system with CODE (494) USA version 

Block diagram of overall COMAND system, shown on model 220 with the following equipment: 

• Code (810) Sound system 
• Code (813) Voice control system (VCS) 
• Code (819) CD changer (6-disk) 

The COMAND operating, display and control unit (A40/3) is the central component in the system. It has a color Liquid Crystal Display (LCD) with video capability for displaying information such as operating menus and map data for navigation. The following systems are operated centrally and menu-assisted on the display:

• Radio
• CD (audio MP3)
• CD player with changer (optional)
• Sound system (optional)
• Navigation system
• Portable CTEL telephone (optional)
• SDARS (optional)
• Telematics services (e.g. emergency call)

Several functions can also be activated with the aid of the multifunction steering wheel switches. It should be noted here that all button actuations on the multifunction steering wheel, which affect the COMAND operating, display and control unit (A40/3n1), are sent first of all from the steering column module (N80) as a Controller Area Network (data bus /CAN bus) (CAN) message to the instrument cluster (A1).

The instrument cluster (A1) links the incoming button actuations with the current menu setting in the multifunction display (A1p13) and then transmits a corresponding CAN message to the COMAND operating, display and control unit (A40/3n1).

The vehicle can be equipped optionally with an infrared remote control for issuing commands from the passenger compartment and with a code (813) Voice control system (VCS), whereby the operator convenience level can be yet again improved.

COMAND operating, display and control unit (A40/3) bus system 

The digital components in the COMAND operating, display and control unit (A40/3n1) are networked through a bus system.

The bus system is used to transmit data (control commands and useful information) between the various system components.

As to some extent the individual components operate with various data formats, or different requirements on bit rate and safety are made, various bus systems are installed:

• Controller Area Network bus class B (interior) (CAN-B)
• Controller Area Network Bus Class C (engine compartment) (CAN-C)
• Media Oriented System Transport (MOST)

Data are exchanged between the external audio components, the telephone system and the voice control system with code (813) Voice control system (VCS) via the MOST. Control data as well as the actual audio signals (e.g. music from CD changer) can be transferred.

The CAN-B is used to connect to further control units in the vehicle (e.g. instrument cluster (A1), steering column module (N80)).

E.g., the instrument cluster (A1) receives via the COMAND operating, display and control unit (A40/3) the audio, telephone and navigation data as well as the time over this bus.

The CAN-C is also networked with the control units that are connected to the CAN-B at the same time. This helps to exchange data that have a direct influence on engine management.

	Radio mode, function		GF82.60-P-2001D
	CD-player mode, function		GF82.60-P-2002AB
	Volume/tone adjustments, function		GF82.60-P-2003AB
	Switch on/off behavior, function		GF82.85-P-2006AB
	Telephone mode, function		GF82.85-P-2007C
	Cassette mode, function	up to 31.8.02	GF82.85-P-2010AB
	Navigation mode, function		GF82.85-P-2012A
	Starguide, function		GF82.85-P-2014A
	Information service, function		GF82.85-P-3016A
	Data transmission for Starguide, function		GF82.85-P-3017A
	Data transfer between COMAND and instrument cluster function		GF82.85-P-3008AB