GF82.85-P-2030FQ Audio Mode, Function

GF82.85-P-2030FQ Audio Mode, Function
MODEL 218
- with CODE (523) MB Audio 20 radio
- with CODE (510) Audio 20 with CD changer
- with CODE (525) MB Audio 50 APS radio
- with CODE (511) Audio 50 APS with DVD changer
- with CODE (512) COMAND APS with DVD changer
- with CODE (526) COMAND with single DVD drive (without navigation)
- with CODE (528) COMAND with DVD changer
MODEL 218 with CODE (527) COMAND APS with single DVD drive (with navigation system)
- except CODE (498) Japan version

Function requirements, general
^ Circuit 30g ON
Audio functions are selected using the following controls:
- Left multifunction steering wheel button group (S110)
- Right multifunction steering wheel button group (S111)
- Audio/COMAND control panel (A40/9)
- Buttons on audio unit
- Voice control system (VCS [SBS])
The audio mode function consists of the following subfunctions:
^ Audio output function sequence
^ Function sequence for volume/tone settings
^ Function sequence for radio mode (FM/AM)
^ Function sequence for DVD/CD audio
^ Function sequence for digital radio (DAB) (with code (537) Digital radio)
^ Function sequence for satellite digital audio radio (SDAR) (with code (536) SIRIUS satellite radio)
^ Function sequence for media interface (with code (518) Media interface)
^ Function sequence for Music Register (with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation))
^ Function sequence for Bluetooth(R) Audio (with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation) or code (528) COMAND incl. DVD changer or code (526) COMAND with single DVD drive (without navigation))

Audio output function sequence
Audio output on vehicles with code (810) Sound system occurs through the sound system amplifier control unit (N40/3), which is actuated by the audio equipment via the Media Oriented System Transport (MOST). The sound system amplifier control unit actuates the following speakers via two direct lines each:
- Center instrument panel speaker (H4/27)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/57)
- Left front door sound system bass speaker (H4/64)
- Right front door sound system bass speaker (H4/65)
- Left front door sound system tweeter (H4/68)
- Right front door sound system tweeter (H4/69)
- Left rear door sound system tweeter (H4/70)
- Right rear door sound system tweeter (H4/71)
- Left front door sound system midrange speaker (H4/72)
- Right front door sound system midrange speaker (H4/73)
- Left rear door sound system midrange speaker (H4/80)
- Right rear door sound system midrange speaker (H4/81)
For the bass speaker (H4/17), the audio signal is transmitted via MOST from the audio equipment to the sound system amplifier control unit and from there using direct lines to the bass speaker via the rear bass speaker amplifier (N40/9).
On vehicles without code (810) Sound system, the audio signals are output by the audio equipment to the following speakers via direct lines:
- Left front door speaker (H4/1)
- Left front door tweeter (H4/1h1)
- Right front door speaker (H4/2)
- Right front door tweeter (H4/2h1)
- Left rear door speaker (H4/3)
- Left rear door tweeter (H4/3h1)
- Right rear door speaker (H4/4)
- Right rear door tweeter (H4/4h1)
In the following, the repetitive list of speakers will no longer be used; instead, the term "speaker system" will be used.

Function sequence for volume/tone settings
All volume and tone settings are performed using the audio unit. This is performed either by the user or automatically by the audio unit.
The volume and tone settings chosen by the user are shown in the Audio/COMAND display (A40/8). Predefined settings can be selected and reset to the manufacturer default setting via the system settings.
With the audio source AUX (via the media interface adapter cable (with code (518) Media interface) or via the AUX jack electrical connector (X39/45) (without code (518) Media interface)), "Standard" and "Boost" can be selected in the "Volume" menu. The input level can be increased by selecting "Boost".
For vehicles with code (810) Sound system, the audio equipment is not only equipped with the general tone settings (treble, bass and balance) but also with the "Logic7(R)" tone setting (surround sound).
The volume setting can be carried out separately for each audio source.
The audio signals are output over the speaker system.
The volume and tone setting partial function is subdivided into the following subfunctions:
^ Function sequence for manual volume/sound settings
^ Function sequence for speed-dependent volume control (SDV [GAL])

Function sequence for manual volume/sound settings
The manual volume/tone setting function is subdivided into the following subfunctions:
^ Function sequence for volume settings via right multifunction steering wheel button group
^ Function sequence for volume settings through the audio unit
^ Function sequence for sound settings via audio/COMAND control panel

Function sequence for volume settings via right multifunction steering wheel button group
Pressing the "+" and "-" button for setting specific functions and volume control (S111s1) enables the volume for the desired audio function to be increased or reduced.
The control signals are forwarded to the audio unit via the following route:
- Buttons + and - for setting specific functions and volume control
- Steering wheel electronics (N135)
- Steering LIN (LIN E1)
- Steering column tube module control unit (N80)
- Chassis CAN (CAN E)
- Instrument cluster (A1)
- Interior CAN
- Audio unit
After evaluating the control signals, the requested settings in vehicles with code (810) Sound system are forwarded via MOST to the sound system amplifier control unit.
On vehicles without code (810) Sound system, the selected settings are processed and amplified internally
The audio output via the speaker system is interrupted by actuating the mute button (S111s6).

Function sequence for volume settings through the audio unit
Operating the rotary switch on the audio unit enables the volume to be raised or lowered for the desired audio function. The control signals are processed internally in the audio equipment.The desired settings in vehicles with code (810) Sound system are forwarded via MOST to the sound system amplifier control unit where they are processed and amplified. On vehicles without code (810) Sound system, the selected settings are processed and amplified internally
The audio output via the speaker system is interrupted by pressing the "MUTE" button on the audio equipment.

Function sequence for sound settings via audio/COMAND control panel
The user can set the corresponding sound by selecting the "Sound" menu on the audio/COMAND control panel.
The control signals of the Audio/COMAND control panel are forwarded to the audio equipment via the telematics CAN (CAN A).
The desired settings are relayed on vehicles with code (810) Sound system via MOST to the sound system amplifier control unit where they are then processed.
In vehicles without code (810) Sound system, the selected settings are processed internally.

Function sequence for speed-dependent volume control
The volume is adapted to the noise level in the vehicle interior with the aid of the speed-dependent volume control defined by the vehicle speed. To do this, the instrument cluster sends the vehicle speed via interior CAN to the audio equipment (without code (810) Sound system) or via MOST to the sound system amplifier control unit (with code (810) Sound system).
The audio equipment or the sound system amplifier control unit raises or lowers the output level to match the vehicle speed.

Function sequence for radio mode (FM/AM)
The antennas receive signals for the FM and AM (SW, MW, and LW) radio frequency bands.
On vehicles with code (494) USA version, the AM frequency band receives MW frequency range signals only.
The following useful signals relevant for the radio reception are modulated onto these signals:
- Music signals
- Speech signals
- Data signals (e.g. traffic information)
The audio device receives the FM-1, FM-2 and the AM signals via the following route:
- AM, FM-1 signals:
- Rear window antenna
- FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier (A2/18)
- Audio equipment
- FM-2 signals:
- Rear window antenna
- FM 2 and DAB antenna amplifier (A2/19)
- Audio equipment
The radio mode function sequence consists of the following subfunctions:
^ Function sequence for AM tuner (MW, LW, SW)
^ Function sequence for FM double tuner with multipath reception (FM)
^ Function sequence for Radio Broadcast Data System (RBDS) (with code (494) USA version) or radio data system (RDS)
^ Function sequence for radio text+
^ Function sequence for High Definition (HD) radio mode (with code (494) USA version)

Function sequence for AM tuner (MW, LW, SW)
For the MW and LW radio frequency bands, the useful signals are broadcast using amplitude modulation (AM). The AM tuner integrated into the audio equipment demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).

Function sequence for FM double tuner with multipath reception (FM)
For the FM radio frequency band, the useful signals are broadcast using frequency modulation (FM).
The dual FM tuner integrated into the audio equipment demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible). The audio equipment also enables a reception-specific switchover between the FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier and the FM 2 and DAB antenna amplifier.

Function sequence for RBDS (with code (494) USA version) or RDS
In addition to the radio program, many radio stations (FM) transmit additional digital information such as station name, program type (e.g. pop, culture) and traffic program identification.
This information is evaluated by the audio equipment and shown on the Audio/COMAND display if the following preconditions are complied with:
- An RDS or RBDS station has been tuned to
- The "RDS or RBDS" function is activated

Function sequence for radio text+
During FM radio operation, additional information can be shown on the Audio/COMAND display. To this end, the "Info" menu item must be selected in the Radio menu.

Function sequence for HD radio mode (with code (494) USA version)
The HD radio function is implemented in the COMAND controller unit.
The integrated HD tuner is a combined AM/FM/Weather band (WB) receiver with HD radio function. It demodulates the analog AM and FM signals using the two integrated double tuners and decodes the digital AM and FM signals using the integrated HD radio decoder chips.
The Weather Band (WB) function enables the reception of the US WB signals.
The HD radio function also allows additional reception of digital carrier waves for analog AM/FM programs, which are also broadcast by the stations.

Function sequence for DVD/CD audio
The DVD/CD audio function enables audio CDs or audio DVDs (including MP3 format) to be played.
User guidance for controlling DVD/CD functionality and displaying supplemental information is carried out via the Audio/COMAND display.
Data exchange between the audio equipment and the Audio/ COMAND display takes place via telematics CAN.
The audio signals are output over the speaker system.

Function sequence for digital radio (DAB) (with code (537) Digital radio)
The Digital Audio Broadcasting control unit (N87/3) allows reception of stations in DAB format.
The Digital Audio Broadcasting control unit receives the DAB Band III signals via the following route:
- Windshield antenna
- FM 2 and DAB antenna amplifier
- Digital Audio Broadcasting control unit
The DAB Band III signals are received the audio equipment via MOST and made available. Control of the DAB functions is accomplished via the audio unit.
The information or displays required for control are shown on the Audio/COMAND display.

Reception-specific switchover from DAB to FM
The audio device transmits the FM station lists to the Digital Audio Broadcasting control unit. If a comparable FM station is found, it is requested by the Digital Audio Broadcasting control unit. If the DAB reception starts to deteriorate, a switch to the FM station of the audio device occurs. The audio signals are output over the vehicle's speaker system.
On vehicles as of 1.7.11 with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation), the reception-specific switchover from DAB to FM is optimized through "Seamless Linking". The digital audio broadcasting control unit compensates for the time offset between the digital and analog signals so that it is virtually impossible to hear the switchover.
This requires that the audio equipment send the FM signals to the MOST when the DAB mode is active.

DAB dual tuner (as of 1.7.11 with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation))
The Digital Audio Broadcasting control unit is designed as a dual tuner and provides not only the known functions but also the following optimizations and extensions:
- Background tuner collects the names of all available stations and Ensembles for display on the Audio/COMAND display
- Display of data for electronic program index "Electronic Program Guide" in the Audio/COMAND display (e.g. broadcast times)
- Faster switchover to another Ensemble
- Almost inaudible switchover between various Ensembles with identical program (e.g. Deutschlandradio in various Ensembles nationwide)
- Support of the extended audio codecs DAB+ and Digital Multimedia Broadcasting (DMB) audio and therefore reception of programs transmitted with these codecs

Function sequence for satellite digital audio radio (SDAR) (with code (536) SIRIUS satellite radio)
The satellite digital audio radio (SDAR) control unit (N87/5) permits the reception of stations from the provider "Sirius satellite radio". The SDAR system is actuated by the COMAND controller unit and implemented through the MOST. The information or displays required for control are output via the Audio/COMAND display and also in the instrument cluster.
The Sirius satellite radio signal is broadcast 3 times to achieve a diversity of channels (using two satellites and one terrestrial transmitter).
The multifunction antenna receives all three channels (Sat 1, Sat 2, terrestrial station) and sends these signals via a direct line to the SDAR control unit.
The SDAR control unit receives and decodes the signals and transmits them to the COMAND controller unit via MOST. The audio signals are output over the speaker system.
The Real Time Traffic Data (RTTD) traffic information service is also available through SDAR.

Function sequence for media interface (with code (518) Media interface)
The media interface allows the following portable devices to be connected to the audio equipment via the media interface electrical connector (X18/70) (a universal device interface) using an adapter cable:
- Auxiliary (AUX) devices (Class 1)
- e.g. video camcorder
- Media Transfer Protocol devices (class 2)
- e.g. "iPod", digital audio player or other universal serial bus (USB) devices via the Media Transfer Protocol
- USB devices (class 3)
- e.g. USB memory sticks, mobile hard disks (mass storage devices)
Adapter cables in angled design are available as accessories for the three adaptation options.
On the following vehicles as of 1.7.11, the USB memory sticks must be connected to the USB electrical connection (X115) in the center console's stowage compartment under the armrest:
- With code (512) COMAND APS with DVD changer
- With code (526) COMAND with single DVD drive (without navigation)
- With code (527) COMAND APS with single DVD drive (with navigation system)
- With code (528) COMAND with DVD changer
With the "AUX" audio source, "Standard" or "Boost" can be selected in the "Volume" menu. The input level can be increased by selecting "Boost". Further operation of the AUX devices takes place in the AUX device itself.
The AUX electrical connection that is installed in the center console's stowage compartment beneath the armrest as standard is no longer needed.
For USB and Media Transfer Protocol devices, the menu navigation and graphical display of the menu navigation are implemented on the Audio/COMAND display and are dependent on the particular portable terminal connected.
The following controls can be used to operate the USB or Media Transfer Protocol device:
- Buttons on audio unit
- Audio/COMAND control panel
- Left multifunction steering wheel button group and right multifunction steering wheel button group
The user can select the "Media interface" menu item as well as the relevant submenu item to have the audio data or video data displayed on the Audio/COMAND display.
The control signals of the multifunction steering wheel button groups are forwarded to the "audio unit" via the following route:
- Left multifunction steering wheel button group and right multifunction steering wheel button group
- Steering wheel electronics
- Steering LIN
- Steering column module control unit
- Chassis CAN
- Instrument cluster
- Interior CAN
- Audio unit
Following evaluation of the control signals in the audio equipment, these are forwarded to the connected portable device via the following route:
- MOST
- Media interface control unit (N125/1)
- Media interface electrical connector
- Media interface adapter cable
- Portable device
The media interface control unit is supplied with voltage via two direct lines (circuit 31g and circuit 30g). If a portable terminal (USB or Media Transfer Protocol) is connected, this is detected by the media interface control unit as follows:
- Media interface adapter cable
- Media interface electrical connector
- Media interface control unit
The audio signals and data from the connected portable device are transferred to the audio equipment via the following route:
- Adapter cable
- Media interface electrical connector
- Media interface control unit
- MOST
Transmission of video signals and data (without code Audio 20 with CD changer and without code (523) MB Audio 20 radio) occurs via a Y - brightness (luminance)/C - color information (chrominance) line to the audio equipment.
The video signals and data are then processed internally and sent via an LVDS line to the Audio/COMAND display.

Function sequence for Music Register (With code (512) COMAND APS incl. DVD changer or code (527) COMAND APS with single DVD drive (with navigation))
On the hard disk integrated into the COMAND controller unit, files (in MP3 format) from various media sources can be saved, e.g. from a CD or a DVD, a memory card, in vehicles as of 1.7.11, from a USB memory stick connected to the USB electrical connection. The files can then be called up as and when required.

Function sequence for Bluetooth(R) audio (with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation) or code (528) COMAND incl. DVD changer or code (526) COMAND with single DVD drive (without navigation))
Via the Bluetooth antenna (A2/91), the COMAND controller unit can receive Bluetooth(R) audio signals from external devices. Bluetooth(R) audio is divided into the following subfunctions:
^ Search for devices and authorization
^ Connection and reconnection
^ Meta data and display of information

Search for devices and authorization
The same options exist for the authorization of a Bluetooth(R) audio source as are available for telephony:
- Search via the device list or
- External authorization
The device lists are set up the same for Bluetooth(R) audio and telephony. In the respective list, only those devices that support the corresponding Bluetooth(R) profile of the respective function are found or displayed during a search.
During telephony, the hands-free profile (HFP) is used. With Bluetooth(R) audio, the Audio/Video Remote Control Profile (AVRCP) and Advanced Audio Distribution Profile (A2DP) are used. If a device supports both functions, it is shown in both lists following authorization.

Connection and reconnection
An authorized device can be connected by means of selection in the corresponding list. If a device is connected that supports both HFP and AVRCP/A2DP, all profiles are connected.
That means that the device is now a telephone and at the same time a source for Bluetooth(R) audio. On most devices, it is necessary to start the player on the telephone so that it can then be controlled via the COMAND controller unit.
When starting, the COMAND controller unit proceeds with the following strategy: First a check is performed as to whether an authorized telephone is inserted in the mobile phone cradle (with code (386) Comfort telephony).
If this is the case, the COMAND controller unit connects to the telephone and assumes the comfort telephony status.
If a mobile phone cradle (with code (386) Comfort telephony) is present but no telephone is inserted, a prompt appears after t = 2 min. as to whether a switch to basic telephony is desired. With "No", the system remains in the comfort telephony status.
If no mobile phone cradle is present or no telephone inserted, the COMAND controller unit searches for the last two telephones. If one of these devices is found, the COMAND controller unit connects to this device. If this device also supports AVRCP/A2DP, these profiles are also connected.
If a device is connected that only supports HFP and a change to the Bluetooth(R) audio application occurs, "No Bluetooth audio device connected" is shown on the COMAND controller unit if corresponding audio sources are shown in the device list.
With the comfort telephony status, the connected device is always treated as if it only supports HFP.
If no Bluetooth(R) audio source is shown in the device list, "No Bluetooth audio device authorized" is shown on the Audio/COMAND display and the selection option "Connect last device" is not shown in the menu.
If a Bluetooth(R) audio source is shown in the device list, the last Bluetooth(R) audio source used can be connected via "Connect last device". However, the connection to the current telephone is interrupted here.
The search process with "Connect last device" can only be interrupted by changing to telephony. Otherwise, the search is continued in the background.
If a device is connected that only supports AVRCP/A2DP and a change to telephony is then made, the connection to the device is disconnected and the COMAND controller unit begins the search for the last two telephones.

Meta data and display of information
The display of information for Bluetooth(R) audio depends on the respective device used. If this supports AVRCP 1.0, "Audio streaming" is exclusively shown on the Audio/COMAND display and in the instrument cluster.
As of AVRCP 1.3, the track, album and artist are shown. In addition, the currently played time of the track can also be conveyed.
Furthermore, there is the option of changing between the normal track sequence and shuffle.
It is possible to jump to the next or the previous track using the left multifunction steering wheel button group.
Notes on supported devices for Bluetooth(R) audio can be found under: http://www.mercedes-benz.com/connect