The audio-system controller (ASK) is a control unit in the MOST network. It serves to manage the audio sources. If interference occurs sporadically during operation, this may be caused by each source in the MOST network. If permanent interference occurs, this will have been caused by restarting an application that has crashed. To rectify the fault, it will be sufficient in most cases to interrupt the power supply to the MOST network for approx. 40 seconds and then perform a restart. At temperatures above 70°C the ASK shuts down. The MOST functions are then no longer available.
The ASK has its own drive on which music can be played. Possible drives are:
Operation is not dependent on the drive version.
The Eject button is used to eject the sound carrier. The function is not dependent on the status of the control unit. If the control display indicates a sound carrier in the ASK which cannot be ejected however, the device is mechanically faulty.
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. If a control unit does not accept a message intended for it, the procedure is repeated by the transmitting control unit up to five times. Nevertheless, if a receiving control unit does not accept the message, the action is not started.
Function |
Via ASK |
Via MFL |
Via CD |
|---|---|---|---|
Next/previous track |
Yes |
Yes |
No |
Rapid search |
Yes |
Yes |
No |
Adjust volume |
Yes |
Yes |
No |
Turning the combined rotary control/push button on the audio-system controller adjusts the volume of the current audio source. If a rotary movement is performed, the ASK transmits a status change to the control display. The control display identifies the currently active audio source and sends a telegram containing the level of the volume to be adjusted and the active source to the ASK and, depending on the equipment fitted, to the Top hi-fi amplifier. These control the volume at the speakers accordingly.
The volume-adjustment function can also be executed at the multifunction steering wheel (MFL). The MFL transmits a status change via the CAN to the control display. The control display processes the status message and sends a telegram containing the new volume value and the current source to the ASK or to the Top hi-fi amplifier. Thus, in the event of a malfunction, the location of the fault can be narrowed down to two control units.
When the auto search button is pressed, the ASK transmits a status change to the control display. The control display identifies the currently active audio source and sends a telegram containing the request to the relevant control unit. The functions can be: next track (drives), next station/channel (TV, radio).
When the auto search button is pressed, the MFL transmits a status change to the control display. The control display identifies the currently active audio source and sends a telegram containing the request to the relevant control unit. The functions can be: next track (drives), next station/channel (TV, radio).