Comand System Function

The following systems can be controlled centrally with the aid of the cockpit management and data system (COMAND):
- Radio
- Integrated CD player and CD changer (optional)
- Sound system (optional)
- Navigation, optionally with dynamic guidance
- Telephone (optional)

In addition, a cassette drive or CD player can be connected over a separate socket in the glove compartment.

The following are in preparation:
- Television (TV, optional)
- Rear monitor (optional)






Block diagram of overall COMAND system illustrated with the following equipment:

- D-network cellular telephone (D2B) (code 317)
- Sound system (code 810)
- Voice control system (VCS) (code 813b)
- Dynamic guidance (code 815)
- CD changer (code 819)

The COMAND operating, display and control module (A40/3) is the central component for the COMAND system. It has a video compatible LCD color display for output of information such as control menus, map data for navigation and television picture (in preparation). Control is possible with fixed function keys and two knobs as well as with menu guidance on the display.

Some functions can be activated in addition with the help of the switches on the multifunction steering wheel. In this case it must be remembered that each actuation of a button on the multifunction steering wheel is first read in by the instrument cluster (A1). The instrument cluster (A1) links the incoming key signals with the current menu setting on the multifunction display and then relays the corresponding CAN message to the COMAND operating, display and control module (A40/3).

As an option the vehicle can also be equipped with an infrared remote control system for control from the rear passenger compartment and with the voice control system (code 813b) for the telephone functions again increasing the operating convenience.

COMAND bus system
The digital COMAND components are linked with one another by a bus system. Data (control commands and utility information) is transferred between the individual system components by the bus system. Since some of the individual components operate with different data formats or have varying requirements regarding the transmission rate and reliability, various bus systems are installed (see block diagram):
- Digital data bus (D2B)
- CAN (A1-A40/3)
- CAN-COMAND

- Data is exchanged between the external audio components (presently only CD changer (A2/6), status 3/99), the telephone system and, if present, the voice control system over the D2B bus (fiber optic cable bus). This includes control data as well as the actual audio signals (music from CD changer, voice for telephone).

- Data exchange with the instrument cluster (A1) is accomplished over the CAN bus (A1 - A40/3). This allows the instrument cluster (A1) to receive the audio, telephone and navigation data for the multifunction display (A1p13) in A1 from the COMAND module as well as the time over this bus. This CAN bus is independent of the CAN passenger compartment!

- The CAN COMAND bus is also independent of the CAN passenger compartment bus and serves for data exchange between the COMAND operating, display and control module (A40/3) and the optional components (not as of introduction) TV tuner (A2/42) and CTEL interface (A34/4), with "Dynamic guidance").