GF82.85-P-3114-08QMJ Operating, Display and Control Unit, Function

GF82.85-P-3114-08QMJ Operating, Display And Control Unit, Function
- with CODE (498) Japanese version


Processing key signals
The control buttons and switches on the function keypad in the COMAND operating, display and control unit (A40/3) are read in via a microcontroller and transferred to the central processor. Depending on the system function, the button operations are processed further in the central computer or passed to other system components in the form of a data telegram via Media Oriented System Transport (MOST).

Graphic editing and image output
The graphic subsystem edits and outputs the operating masks. The operating masks are output internally from the graphics subsystem on the display of the COMAND operating, display and control unit (A40/3).
The information and amplitudes of the 3 colors red, green and blue as well as a synchronization signal are included in the FBAS signal.

The electronic circuitry in the display unit evaluates the signal and controls the individual display dots line by line in terms of color and intensity. There is a pulse at the end of each line which synchronizes the horizontal video signal. The electronic circuitry of the display unit then starts the next line. Upon reaching the last line a pulse is received, which synchronizes the vertical video signal. This causes the electronic circuitry to start the first line again.

Audio signal output
The audio signals from the various sources (CD, navigation system voice output) are prepared by the COMAND operating, display and control unit (A40/3) and amplified before being output via the vehicle speakers.
With code (810) sound system, final amplification of the audio signals is carried out by the sound amplifier (A2/13). For this purpose, the audio source data is digitally transferred to the sound amplifier (A2/13).

On-board diagnosis (OBD), display on screen
The following functions are incorporated in the information on the display of the COMAND operating, display and control unit (A40/3):
^ Warm start (operating condition)
^ Battery voltage (e.g. 13.21 V)
^ Number of satellites available and position
^ Direction of travel (forward or reverse)
^ Vehicle speed (km/h or mph)

At least 4 satellites are required for the first position calculation; 3 satellites are sufficient for other calculations. If these requirements for position calculation do not exist, only the number of satellites appears in the display.

Off-board diagnosis
While the COMAND operating, display and control unit (A40/3) is active, the system saves all faults that occur in the non-volatile memory. These faults can be read out using STAR DIAGNOSIS via the data link connector (X11/4).

It is not possible to output faults on the display of the COMAND operating, display and control unit (A40/3). The fault management function of the COMAND operating, display and control unit (A40/3) also includes the components connected to the Media Oriented System Transport (MOST) system. Each MOST component has its own fault memory. When requested by STAR DIAGNOSIS, the faults are transferred to the COMAND operating, display and control unit (A40/3) via MOST and can then be read out using the data link connector (X11/4).

Navigation processor
The navigation processor is a central component of the COMAND operating, display and control unit (A40/3). It reads the data from the navigation CD inserted in the digital versatile disk (DVD) ROM drive then calculates the position of the vehicle from the incoming signals and the route once the user has entered the destination.

DVD and DVD ROM drive
Data from the navigation DVD can be read using the integrated DVD ROM drive.

The DVD contains the following:
^ Program data for execution in navigation processor
^ Voice data for voice output
^ Map data.

Traffic data recorder
The data is stored for a maximum of 30 minutes in the traffic data recorder (up to 100 messages) even during the run-on time of the COMAND operating, display and control unit (A40/3).

The traffic data recorder decodes the messages and sends them on to the integrated navigation processor as required. The traffic data recorder requires an up-to-date "location list" from the navigation processor for synchronization purposes. The monitory points for checking the network of roads (e.g. freeway exits) are defined by clear numbers in the "location list". This "location list" is stored on the DVD. It is loaded automatically (e.g. if DVD is changed) from the navigation processor into the non-volatile traffic data recorder.