The ASK Audio System Controller manages all the audio signals of the Top HiFi audio system. The audio system controller is the network and timing master in the MOST network.
Depending on their function, the audio sources are subdivided into entertainment and infotainment.
Entertainment: "Entertainment" includes all the entertainment functions. These include radio, television, and playback of video and audio recordings. The volume of the active source is adjusted by means of the rotary pushbutton.
Infotainment: Infotainment includes Check Control messages, the PDC gong and navigation announcements. The volume of navigation announcements is adjusted by means of the volume rotary pushbutton. The volume of the other infotainment sources is set by means of coding.
The audio system controller (AKS) is a control unit in the MOST framework and it is responsible for management of all audio signals.
The control elements of the Audio Display Panel (ADP) are used to switch the audio system controller (ASK) on and off and to operate it (see functional description: Audio Display Panel (ADP).
The ASK also generates a number of audible sounds, e.g. the PDC (Park Distance Control) gong.
At a temperature greater than 70°C, the ASK switches off. The MOST functions are then no longer available.
The Control Display (CD) and Central Information Display (CID) are separate components. The Control Display (CD) with the Central Information Display (CID) and the Controller (CON) contains the operation and display elements for the vehicle electronics, with the exception of the ADP functions.
The Control Display (CD) co-ordinates the function requests from the system and assigns them to the individual functions. For the Control Display (CD), the following is displayed on the tester:
The Central Information Display (CID) is the display unit. For the Central Information Display (CID), the following is displayed on the tester:
The navigation data and operation options for the navigation, audio and video functions are displayed at the Central Information Display (CID).
The Controller (CON) is the control element for the Control Display (CD) with the display unit Central Information Display (CID). To run operating functions, the front Controller (CON) is folded out of the centre armrest.
The output stages for the subwoofers and door loudspeakers are integrated in the Top HiFi amplifier. The output stages for the front door speakers and rear parcel shelf are located in the audio system controller. Acoustic control is assumed by the Top hi-fi amplifier. The Top hi-fi amplifier is a node in the MOST network.
The MOST (Media Oriented Systems Transport) bus links the audio, video and navigation systems. Information relating to function requests is transmitted to the relevant control units by means of MOST bus messages.
The aerial tuner supplies the LF signals on the MOST bus. The audio system controller (ASK) provides the audio channels. However, the LF signals are processed and output by the amplifier.
The ”mute” function mutes the audio output with its functions (tuner, CD player, CD changer, cassette play). In CD mode, CD changer mode or audio cassette mode, the relevant player is also stopped.
The ”mute” function mutes the audio output or reduces the audio volume. In addition, the CD /CDC as well as the DVD drive can be stopped. The ”mute” function is activated by the audio system controller (ASK) on the basis of the following prioritization:
In the case of Top HiFi amplifiers, the Audio System Controller (ASK) provides the 7-band equalizing function.
With the 7-band equalizing function, the volume is raised in a co-ordinated sound range when a settable speed threshold is exceeded. This volume increase compensates for the noises generated by the vehicle acoustics as the car is being driven. The volume of the individual frequency bands, and particularly the lower frequencies, is individually adjusted in response to the speed signal.
The Control Display (CD) coordinates the function requests from the system and assigns them to the relevant functions.
The audio system controller (ASK) selects the sources for audio signal output depending on the request. The audio system controller decides whether an audio signal can be overlaid by another source or completely muted.
The Control Display (CD) is the only control unit that knows the function (listen radio) set in the system. If the volume is to be increased (function request), the Control Display (CD) sends a message to that effect to the audio system controller (ASK) in the form of a telegram. This telegram also contains the information indicating to which audio source the volume adjustment applies. Infotainment audio output is always a certain degree louder than the entertainment sources.
In diagnosis, each individual audio output channel can be activated via the ASK control unit. The command can be reset via diagnosis or by operating an audio function.
For testing purposes, always use the CD Sound Test.
The telephone ringing tone is generated by the telephone itself. If the ringing tone of an incoming telephone call can be heard, the audio system controller (ASK) sets up a correct connection. If problems nevertheless occur, they are more likely to be attributable to the telephone than to the ASK.
For this reason, it can occur in the Top HiFi function that infotainment sources are output (except navigation), but no audio output for entertainment is possible.
The audio system controller (AKS) generates the network error entries.