Audio 50 APS, function - GF82.61-P-0003TM

MODEL 211.0/2 as of 1.6.06 with CODE (525) MB Audio 50 APS radio

Fig 1: Locating Audio 50 APS Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Function

The radio control panel and navigation unit is the central operating unit for the entertainment and communication systems integrated in the vehicle within the Media Oriented System Transport (MOST). All the system components and control units can be selected and operated via the radio control panel and navigation unit and in addition via the left multifunction steering wheel button group and right multifunction steering wheel button group. The radio control panel and navigation unit has a color liquid crystal display (LCD) for displaying information such as operating menus and map data for navigation.

The radio control panel and navigation unit can be operated using 3 main control panels, which can be found to the left and right of and below the screen, a cross-shaped rocker button (Cursor, Enter) and a rotary switch (Volume, ON/OFF).

Controls for the radio control panel and navigation unit are:

permanently programmed function keys
alphanumeric key block
programmable function keys
Rotary switch with integral ON button
Direction input element with OK button
Voice repeat button for navigation
mute button

Part of the controls are assigned with fixed functions, i.e. irrespective of the screen applied in each case they always trigger the same function. Some functions can be activated using the left multifunction steering wheel button group and right multifunction steering wheel button group.

However, these button operations are initially processed by the instrument cluster.

The instrument cluster links the incoming button operations with the current menu setting at the multifunction display (A1p13). It transmits, where necessary, a corresponding Controller Area Network bus class B (interior) (CAN-B) message to the radio control panel and navigation unit via the audio gateway control unit.

The following functions can be operated centrally:

Radio mode
CD player mode
Navigation mode
Telephone mode
Voice control
External audio devices via the AUX jack

System components of the radio control panel and navigation unit involved for full equipment version:

Integrated navigation processor
Universal Portable CTEL Interface (UPCI [UHI]) control unit (telephone, SMS)
Voice control system control unit
Audio gateway control unit (includes radio receiver, radio amplifier, CAN-B interface, MOST interface and audio processor)
CD changer
Multifunction steering wheel (MFL)
Instrument cluster

Additional audio sources such as an MP3 player can be integrated in the front entertainment system via the AUX jack. The AUX jack is located in the glove compartment.

MOST

The digital components and the radio control panel and navigation unit are linked with one another by MOST. The MOST is used to transmit data (control commands and useful information) between the various system components. In the process both control data and the actual audio signals are transmitted (music from CD changer, voice when phoning).

Since some of the individual components work with different data formats or require different data transfer rates and security levels, different bus systems have been installed.

Data bus systems:

MOST
CAN-B
Controller Area Network bus, class C (engine compartment) (CAN C)

Data or signals are exchanged via the MOST between the audio gateway control unit, the radio control panel and navigation unit, the CD changer, the Universal Portable CTEL Interface (UPCI [UHI]) control unit and the voice control system control unit. In the process both control data and the actual audio signals are transmitted (music from CD changer, voice when phoning). The radio control panel and navigation unit communicates with the audio gateway control unit and the other system components via the integrated MOST interface.

Interfaces

The CAN-B is used for data exchange with the instrument cluster. This is how the instrument cluster receives the audio, telephone and navigation data for the multifunction display in the instrument cluster and the time via the audio gateway control unit from the radio control panel and navigation unit.

The time can also be synchronized between the radio control panel and navigation unit and the instrument cluster via the MFL. The CAN-C is linked to the CAN-B via the central gateway control unit in order to receive data for position finding.

The data read in by the ESP control unit (N47-5) are placed on CAN-C and are available on CAN-B via the central gateway control unit and are available via the audio gateway control unit on the MOST and thus also to the navigation processor of the radio control panel and navigation unit.

Audio 50 APS volume/tone settings		GF82.61-P-0003-01TM
Audio 50 APS switch on/off characteristics		GF82.61-P-0003-02TM
Audio 50 APS networking of components		GF82.61-P-0003-03TM
Navigation mode, function		GF82.85-P-2012TME
Communications, function	Telephone, SMS	GF82.85-P-2016TME
Audio mode, function	Radio, CD	GF82.85-P-2030TME