Radio Mode

Block diagram of COMAND radio system, illustrated with antenna system for model 210.0 with the following equipment:
- Sound system (code 810)

The parts marked are the components most significant for radio operation.

The COMAND radio menu can be activated by pressing the "RADIO" button on the COMAND operating, display and control module (A40/3).

Radio reception, function
NOTE: The antenna system versions differ depending on the vehicle model . The following description uses the antenna system for models 208 (except 208.4) and 210 (except 210.2) as examples.

The antennas in the rear window receive high frequency FM, MW and LW signals. These high frequency signals carry the music, voice and/or data signals. The two top left/bottom left rear window antenna amplifiers (A2/8, A2/24) filter the frequencies for the radio frequency bands out of the high-frequency signals received and amplify the filtered frequencies. The amplified signals are then transmitted from the A2/24 via a common coaxial lead (FM, AM) to the radio receiver (is integrated in A40/3). The radio receiver demodulates the high frequency signals, meaning it separates the information (audio frequencies) from the carrier signal (not audible). The demodulated audio signals are amplified and converted into sound signals by the vehicle loudspeakers.

FM antenna diversity feature (not on model 208.4, 210.2)
With the antenna diversity feature, switch over is accomplished between the FM antennas in the rear window depending on the reception. This is accomplished automatically by the bottom left rear window antenna amplifier (A2/24).
The radio tuner in the COMAND operating, display and control module (A40/3) generates only the "IF" signal (intermediate frequency), which serves as a reference for the antenna amplifier module for switching the FM antennas.

Dual-receiver technology, function
A second (integrated) radio receiver generates a list of the FM stations automatically after the COMAND system is switched on and updates this list continuously during operation. This list appears in alphabetical order when the "FM station list" menu is called. The stations displayed can be activated by selecting and confirming.

NOTE: The station list is available only when the RDS feature is activated.

If reception interference occurs whilst driving, the COMAND system attempts to receive the selected station on one of the alternative frequencies with the aid of the second receiver and, if the reception is better, to switch over.

NOTE: Some programs from the broadcasting networks are subdivided into regional programs at certain times. Since COMMAND changes to an alternative transmission frequency automatically, in the event of reception interference, this can also lead to a change in the regional program. If this is not desired, the entry "Regional program" can be activated in the "FM settings" menu.

Radio Data System (RDS), function
Many radio stations (FM) transmit additional digital information such as the station name, type of program (PTY) (e.g. pop, culture, ..) and traffic radio recognition in addition to the radio program. This information is evaluated by the COMAND module and displayed on the monitor when:
- an RDS station is tuned in and
- the RDS feature is activated.

In addition, the radio components in the COMAND system offer:
- a list of the momentarily strongest FM stations in the RDS mode
- an automatic memory for the strongest FM/LW stations
- selection of the program type (PTY, e.g. culture, sport, pop) for FM stations in the RDS mode

COMMAND offers the following possibilities for station selection:
- Manual station search
- Automatic station search with scan function (stations within a frequency range are played for 8 s)
- Station selection from memory (10 stations per frequency range)
- Station selection by entering frequency with the number pad (e.g. 92.2 MHz)
- Station selection from the FM station list