Radio mode, function - GF82.60-P-2001D

MODEL 215, 220 with CODE (352) COMAND operating and display system

Fig 1: Block Diagram Of COMAND Radio System Up To 31.8.03 - Shown On Model 220

Block diagram of COMAND radio system up to 31.8.03, shown on model 220 with code (810) Sound system and code (819) CD changer (6-disk)

Fig 2: Block Diagram Of COMAND Radio System As Of 1.9.03, Shown On Model 215

Block diagram of COMAND radio system as of 1.9.03, shown on model 215 with code (810) Sound system and code (819) CD changer (6-disk)

On vehicles as of 1.9.03, all audio signals of the audio components, voice signals as well as the signals of the navigation processor (N41/1) are transmitted via the Media Oriented System Transport (MOST).

On vehicles as of 1.9.03, the audio gateway control unit (N93/1) is also installed as an interface between the Controller Area Network bus class B (interior) (CAN-B) and the Media Oriented System Transport (MOST). The audio signals are then sent to the audio gateway control unit (N93/1) and output via the vehicle speakers.

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

Radio system function

The antennae in the rear window receive FM, MW and LW high-frequency signals.

The music, voice or data signals are modulated upon these high frequency signals. The rear window antenna amplifier module (A2/12) filters the radio frequency band frequencies from the received high-frequency signals and amplifies these. The amplified signals are then transmitted to the radio receiver by the rear window antenna amplifier module (A2/12) via a coaxial cable (FM, AM).

The radio receiver demodulates the high frequency signals, in other words it separates the useful information (audible frequencies) from the carrier signal (inaudible).

The demodulated audio signals are amplified and then converted to sound signals by the vehicle speakers.

The COMAND operating, display and control unit (A40/3) also offers the option for requesting information on the current weather conditions at any time. This information is transmitted via the weather channels.

FM antenna diversity, function

With the antenna diversity function a switchover which is dependent on reception is performed between the 4 FM antenna of the rear window. The function is automatic and is carried out by the rear window antenna amplifier module (A2/12). The radio tuner of the COMAND operating, display and control unit (A40/3) merely generates the "IF" signal which serves the rear window antenna amplifier module (A2/12) as a reference for switching from one FM antenna to the other.

The COMAND operating, display and control unit (A40/3) offers the following options for station selection:

Manual station search
Automatic station search with scan function (the stations in the frequency range are each played for 8 s)
station selection from the memory (10 stations per waveband)
Station selection by frequency input using the number keypad

Satellite radio reception

Optionally a receiver for satellite radio can be installed. The reception of digital radio stations via satellite can be requested with the SAT-button on the COMAND operating, display and control unit (A40/3). However, the system has to be enabled by a service provider. Once the system has been enabled, up to 224 additional stations can be received.

Volume/tone adjustments, function		GF82.60-P-2003AB
Antenna amplifier module, location/task/design/function		GF82.62-P-3105A
Rear window antenna, location/task/design/function		GF82.62-P-3106A
Sound amplifier, location/task/design/function	With code (810) Sound system up to 31.8.03	GF82.62-P-3100A
	With code (810) Sound system as of 1.9.03	GF82.62-P-3100AB
Radio satellites, location/task	as of 1.9.03	GF82.85-P-3113B
Radio satellite antenna, location/task	as of 1.9.03	GF82.62-P-4109B
Audio gateway control unit, location/task/design	as of 1.9.03	GF82.62-P-3116SZ