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

GF82.85-P-3114-08GH Operating Display Unit With Control Module, Function
- with CODE (352a) COMAND operating and display system
- except CODE (491) U.S. version
- except CODE (498) Japanese version

Processing of button actuations
The control buttons and switches on the function keypad in the COMAND operating, display and control module (A40/3) are read in over the microcontroller I/O ports and transferred to the central processor. Depending on the system function, the button actuations are further processed in the central processor or transferred to other system components via the Digital Data Bus ( D2B) in the form of a data telegram.

Graphics preparation and image output
The graphics subsystem handles the preparation and output of the operating screens. The operating screens are output internally by the graphics subsystem over the RGB output ( R=Red, G=Green, B=Blue) to the display.

The RGB signal contains the information and amplitudes of the three basic colors Red, Green and Blue, as well as a synchronization signal. The control electronics in the display unit evaluate the RGB signal and activate the individual display pixels line by line in terms of color and intensity.

A horizontal synchronization pulse occurs at the end of each line. The electronic circuitry of the display unit then starts the next line. Once the last line of the display has been reached, the vertical synchronization pulse follows; the electronic circuitry activates the first line again.

Audio signal output
The audio signals from the various sources (CD, destination-finding system voice output,..) are prepared by the COMAND operating, display and control module (A40/3n1) and amplified before being output on the vehicle loudspeakers. With sound system (Code 810) the final amplification of the audio signals is performed by the sound amplifier (A2/13). For this purpose, the audio source data are transmitted over the Digital Data Bus ( D2B) to the sound amplifier (A2/13).

Info menu
Using the "i" or "INF button" the Info menu can be accessed directly. This functionality can be selected independently of source (e.g. from the cellular telephone or radio menu).

The Return button is used to go back to the screen from which Info was selected.

If the "Point" mode was selected in the Info menu, the system switches to the screen preceding the Info menu when the Return button is pressed.

Indication in display
The following information is given under Info:
- Warm start (operating condition)
- Battery voltage: e.g. 13.21V (battery voltage)
- GPS: Number Position (number and position of available satellites)
- Direction: forward/reverse (direction of travel)
- Speed: km/h mph (vehicle speed)

At least 4 satellites are required for dead reckoning, 3 satellites are sufficient for other calculations.

If these prerequisites for position calculation are not available, only the number of satellites is given in the display.

Diagnostic interface (K bus) and D2B component error management
During operation, the system stores all errors that occur in the non- volatile memory. These errors can then be read out via the diagnostic interface (K bus) using the STAR diagnosis tool. Output of the errors on the display unit is not possible.

The COMAND operating, display and control module (A40/3) error management also extends to the components connected to the Digital Data Bus (D2B). Each D2B component has its own DTC memory.

The errors are transmitted upon the request of the STAR diagnosis tool via the Digital Data Bus (D2B) to the COMAND operating,display and control module (A40/3) and can then be read out via the diagnostic interface.

Navigation computer and GPS control module
The navigation computer is the central component of the COMAND operating, display and control module (A40/3). It is integrated in the COMAND operating, display and control module (A40/3) and calculates the vehicle's position from the incoming signals and its route in accordance with the specified destination.

The GPS control module is part of the navigation. It evaluates the satellite signals which are received by the CTEL and GPS roof antenna (A2/49) and are distributed via the telephone and GPS antenna splitter (A2/57). The vehicle's position is calculated from this data.

CD-ROM and CD drive
With the aid of the integral CD drive data can be read from the special Navigation CD, or audio CDs can be played.

following is stored on the Navigation CD:
- Program data for execution in the navigation computer
- Voice data for voice output
- Map data.

Note in Navi-CD screen:
"Please insert Navi-CD type DX "

This instruction is to ensure that the customer has bought the correct CD.

The digitized map area on the CD-ROM contains towns, cities, streets, intersections and their attributes (e.g.: one-way streets, turning restrictions); it does not contain information about company-owned and private land, farms, housing estates and paths.

Rotational speed sensor (gyro sensor)
determines changes in the vehicle's direction. It is built into the navigation computer. No calibration is required.

Traffic data memory
The integral traffic data recorder receives traffic announcements either via RB-CAN (in TCS mode) or internally from the b radio tuner (in TMC mode).

The data is stored for a maximum of 30 min, even during the COMAND run-on time, in the traffic data recorder (up to 100 messages ).

The traffic data recorder decodes the messages and forwards them if necessary to the navigation computer. For synchronization the traffic data memory requires a current "location list" from the navigation processor.

The monitoring points (e.g. highway on-ramp) necessary for checking the road network are defined in the " location list" by unique numbers.

The " location list" is stored on the Navigation CD. If necessary, it is loaded (e.g. changing the CD) automatically from the navigation computer into the traffic data recorder in a non-volatile form.