GF82.85-P-3114-08QM Operating, Display Unit With Control Unit, Function

GF82.85-P-3114-08QM Operating, Display Unit With Control Unit, Function
- with CODE (527) COMAND APS (with navigation)

Processing key signals
The control buttons and switches on the function keypad on the COMAND operating, display and control unit (A40/3) are read in via the microcontroller I/O ports and transferred to the central processor. Depending on the system function, the keys pressed are processed in the central computer or transmitted to the other system components over Media Oriented System Transport (MOST) and Controller Area Network bus class B (interior) (CAN- B) in the form of a data telegram.

Graphic editing and image output
The video subsystem takes over editing and output of the control displays. The operating screens are output internally to the display by the graphics subsystem via the composite color video signal input.
The information and amplitudes of the 3 primary colors red, green and blue as well as a synchronization signal are included in the composite color video signal.

The control electronics in the display unit evaluates the composite color video signal and controls the individual pixels line by line in terms of color and intensity. At the end of each line, there is a pulse that synchronizes the horizontal video signal. The electronic circuitry of the display unit then starts the next line. After reaching the last line of the display, the vertical video signal is synchronized; the control electronics triggers the first line again.

Audio signal output
The audio signals from the various sources (CD, voice output for navigation etc.) are processed by the COMAND operating, display and control unit (A40/3) and amplified for output via the vehicle loudspeakers. With code (810) sound system, the 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).

Info menu
Using the "i" or "INF" keys takes you straight to the information menu. This functionality can be selected independently of source (e.g. from the telephone or radio menu). A return is made to the screen from which the Info menu was selected by means of the Back key. If "Mode" was selected in the Info menu, the system switches to the screen preceding the Info menu when the Back key is pressed.

Diagnosis interface (K-line) and fault management
While the COMAND operating, display and control unit (A40/3) is active, the system stores all occurring faults in a nonvolatile memory. These can be read out via the data link connector (X11/4) using STAR DIAGNOSIS. Output of the errors on the display unit is not possible. The diagnosis also includes the components connected to the MOST ring. Each MOST component has its own fault memory. The faults are transferred to the COMAND operating, display and control unit (A40/3) via MOST upon request by STAR DIAGNOSIS and can then be read out.

Navigation processor and GPS control unit.
The navigation processor integrated into the COMAND operating, display and control unit (A40/3) is the central component of the navigation system. It calculates the location from the incoming signals and the route of the vehicle according to the destination entry. The GPS control unit is part of the navigation processor. It evaluates the satellite signals coming from the GPS antenna (A2/23) and calculates the vehicle position from this information.

Position finding
For the initial position calculation, at least 4 satellites are required, for further calculations 3 satellites are adequate. If this condition for position calculation is not met, then only the number of satellites received appears in the display of the COMAND operating, display and control unit (A40/3).

Digital versatile disk (DVD) and DVD-ROM drive
Data can be read from the special navigation DVD or audio CDs played using the integrated DVD-ROM drive.

The following data is provided on the navigation DVD.
^ Program data for execution in navigation processor
^ Voice data for voice output
^ Map data.

Message in the Navi DVD screen: "Pleas insert navigation DVD". This message is intended to ensure that the user has inserted the right DVD.

The digitized map area on the DVD contains towns, cities, streets, intersections and their attributes (e.g. one-way streets, turn prohibitions). It does not contain information about company and private land, farms, housing estates and paths.

The traffic data memory
The integral traffic data recorder receives the traffic messages either via MOST or internally from the radio tuner.

The data are stored for a maximum of 30 minutes in the traffic data recorder, even during the run-on time of the COMAND operating, display and control unit (A40/3) (up to 100 messages). The traffic data memory decodes the messages and transmits them to the navigation processor as required. For synchronization, the traffic data recorder requires a current location list from the navigation processor. The monitory points required for checking the road network (e.g. freeway exit) are defined by unambiguous numbers in this list. The location list is stored on the DVD. It is loaded when needed (e.g. if DVD is changed) from the navigation processor into the traffic data recorder.

Gyrosensor
The gyrosensor determines the direction changes of the vehicle. It is installed in the navigation processor. Calibration is not required.