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

GF82.85-P-2030LEU Audio Mode, Function
MODEL 216, 221
- with CODE (530) COMAND APS USA (with navigation system) as of model year 2009 /YoM 08

Function requirements, audio mode, general
^ Circuit 30g ON

General information on the audio mode
The audio mode consists of the following component functions:
^ Function sequence for radio mode (AM/FM)
^ Disk and MP3 function sequence
The following components are available for control of the audio system:
- Front central operating unit (A40/9)
- Left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111)
- Handsfree system microphone group (A67b1) (up to 31.5.09 with code (813) Voice control system (VCS [SBS]) or as of 1.6.09)
- Center console button group (S148)
- Remote control (with code (816) Entertainment remote control or code (867) SPLITVIEW or for model 221 with code (864) Rear entertainment system)

Function sequence for radio mode (AM/FM)
The antennas structures in the rear window receive signals for the FM and AM (MW) radio frequency bands.
The following useful signals relevant for the radio reception are modulated onto these signals:
- Music signals
- Speech signals
- Data signals (e.g. weather band (WB), weather information)
These signals are routed over direct lines to the rear window antenna amplifier module (A2/12). The rear window antenna amplifier module filters the radio frequency band frequencies from the received signals, and amplifies them.
The amplified signals are then sent over coaxial cables (FM, AM) to the audio tuner control unit (N93/1) (up to 31.5.09) or to the high definition tuner control unit (N87/8) (as of 1.6.09) where they are demodulated.
The high definition tuner control unit sends the audio signals over the Media Oriented System Transport (MOST) to the audio tuner control unit or to the digital sound processor (A2/69) (model 221 as of 1.9.10 with code (811) Advanced Sound System), which then processes and amplifies them before emitting them through the vehicle's speaker system.
The audio output in model 216 takes place using the following components:
- Left door rear speaker (H4/3)
- Right door rear speaker (H4/4)
- Bass module speaker (H4/17)
- Center cockpit speaker (centerfill) (H4/27)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/57)
- Left door Sound tweeter (H4/68)
- Right door Sound tweeter (H4/69)
- Left door Sound woofer and midrange speaker group (H4/72)
- Right door Sound woofer and midrange speaker group (H4/73)
Audio output in model 221 except 221 (as of 1.9.10) with code (811) Advanced Sound System is through the following components:
- Left rear door speaker group (H4/3)
- Right rear door speaker group (H4/4)
- Bass module speaker
- Center cockpit speaker (centerfill)
- Left rear surround speaker
- Right rear surround speaker
- Left front door Sound tweeter (H4/68)
- Right front door Sound tweeter (H4/69)
- Left front door Sound woofer and midrange speaker group (H4/72)
- Right front door Sound woofer and midrange speaker group (H4/73)
Audio output in model 221 (as of 1.9.10) with code (811) Advanced Sound System is through the following components:
- Left front door speaker (H4/5)
- Right front door speaker (H4/6)
- Bass module speaker
- Center cockpit speaker (centerfill)
- Left front door tweeter (H4/33)
- Right front door tweeter (H4/34)
- Left rear door tweeter (H4/35)
- Right rear door tweeter (H4/36)
- Left rear surround speaker
- Right rear surround speaker
- Left front door woofer (H4/64)
- Right front door woofer (H4/65)
- Left rear door woofer (H4/66)
- Right rear door woofer (H4/67)
The woofers and bass box speaker on model 221 (as of 1.9.10) with code (811) Advanced Sound System are actuated by the sound amplifier (A2/13), which is controlled by the digital sound processor.
The user interface is generated by the COMAND controller unit (A40/3) and shown on the COMAND display (A40/8) (without code (867) SPLITVIEW) or on the SPLITVIEW display (A40/10) (with code (867) SPLITVIEW).
The radio mode (AM/FM) function is made up of the following subfunctions:
^ Function sequence for AM reception (MW)
^ Function sequence for FM reception
^ Function sequence of Radio Broadcast Data System (RBDS) reception

Function sequence for AM reception (MW)
These useful signals are transmitted by means of amplitude modulation on the radio frequency bands. The AM tuner integrated into the audio tuner control unit demodulates these signals. In other words, it separates the useful signals (audible frequencies) from the carrier signal (inaudible).

Function sequence for FM reception
For the FM radio frequency band, the useful signals are transmitted using frequency modulation. The FM twin tuner integrated into the audio tuner control unit demodulates these signals.
In other words, it also separates the useful signals (audible frequencies) from the carrier signal (inaudible). The audio tuner control unit also enables an automatic reception-specific changeover.

Additional function requirements for RBDS reception
^ RBDS function activated
^ Radio stations also transmit additional digital information

Function sequence for RBDS reception
Apart from the normal radio program, many radio stations (FM) transmit additional digital information such as station names, program type (e.g. pop, culture) and traffic program identification.
This information is evaluated by the COMAND controller unit and shown on the COMAND display or the SPLITVIEW display.

Disk and MP3 function sequence
A 6-disk DVD changer is integrated into the COMAND controller unit. This DVD changer can play the following media and formats:
- DVD video
- DVD audio
- DVD-ROM (audio/video data)
- Audio CD
- CD-ROM (Audio or video data)
- CD-R
- CD-R/W
- MP3
- WMA (Windows Media Audio)
The user guidance for controlling the DVD functionality (e.g. track selection) and the display of supplemental information (e.g. track) take place on the COMAND display or the SPLITVIEW display.