Operating/display unit with control module, function - GF82.85-P-3114-08D

Models 208, 210 with code 352a

Processing button actuations

The operation keys and switches for the function keypad in the COMAND operating, display and control module (A40/3n1) are read in by the I/O ports of the micro-controller and provided to the central processor. Depending on the system function, the key signals are processed in the central processor or relayed to the other system components by the bus system (digital data bus (D2B), CAN (A1 - A40/3) or (RB CAN), in the form of a data telegram. 3

Graphic processing and screen output

The graphic subsystem handles processing and outputs of the control displays The control displays are output internally by the graphic subsystem via the RGB output (r =r ed, g =g reen, b =b lue on the display. In the RGB signal information and amplitudes of the three basic colors c red, green and blue as well as a synchronous signal are included.

The electronic control circuitry on the display unit evaluates the RGB signal and controls the individual pixels line by line according to color and intensity. A horizontal synchronization pulse is output at the end of each line The electronic circuitry of the display unit then starts the next line. When the last line of the display is reached the vertical synchronization pulse is output causing the electronic circuitry to start again with the first line.

Audio signal output

The audio signals of the various sources (CD, voice output for route guidance...) are processed by the COMAND operating, display and control module (A40/3) and amplified before they are output on the vehicle loudspeakers. With the sound system (code 810) final amplification of the audio signals is accomplished by the sound system amplifier (N40/3) . For this purpose the source data is transmitted analog to the sound system amplifier (N40/3) via a separate line.

Info menu as of 01.06.01

With the " i" or "INF button" it is possible to jump directly to the Info menu. This function can be selected regardless of the source (e.g. from telephone or radio menu).

With the return button it is possible to go back to the screen where Info was selected. If the mode point is selected in the Info menu, the display preceding the Info menu appears when the return button is pressed.

On-board diagnosis/display on screen

Under Infos the following features are included:

Up to 31.05.01

Warm start (operating condition)
Battery voltage: e.g. 13.21V (battery voltage)

Supplement as of 01.06.01

GPS: Number position (number of satellites available and position)
Direction: forward/reverse (direction of motion)
Speed: km/h mph (speed)

For position calculation at least 4 satellites are required, for additional calculations 3 satellites are sufficient. If these prerequisites for position calculation are not present, only the number of satellites appears on the display .

Diagnosis interface (K-bus) and D2B component fault management

During operation the system stores all occurred errors in the nonvolatile memory. They can be read out via diagnostic interface (K-bus) by the STAR diagnosis tool Output of the errors on the display unit is not possible.

The COMAND error management includes components connected to the D2B bus . Each D2B component has its own DTC memory .

The errors are transferred to the COMAND operating, display and control module (A40/3n1) by the STAR diagnosis tool via the D2B bus and can be read out by the diagnostic interface.

Navigation processor and GPS control module

The navigation processor is the central component of the COMAND navigation system. It is integrated into the COMAND operating, display and control module (A40/3) and calculates the locations from the incoming signals as well as calculating the vehicle route after the destination has been entered.

The GPS control module is part of the navigation processor. It evaluates the satellite signals coming from the GPS antenna (A2/49a2) and calculates the vehicle position from this information.

CD-ROM and CD-ROM drive

With the aid of the integrated CD drive data from the special navigation CD can be read or audio CD's can be played.

The following features are included in the navigation CD-ROM :

Program data for execution in navigation processor
Voice data for voice output
Map data.

Notes on navi-CD screen:

up to 31.05.01; " Please insert navi CD "

as of 01.06.01; "Please insert navi CD model DX "

This display is intended to ensure that customers procure the correct CD .

The digitized map area on the CD-ROM contains towns, cities, streets, intersections and their attributes (e.g.: one-way streets, turn prohibitions...); not included are e.g. company and private lots, farms, small residential areas and rural roads.

Gyro sensor

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

Traffic data memory

The integrated traffic data memory receives the traffic messages either via the RB-CAN bus (with TCS mode) or internally from the radio tuner (with TMC mode).

The data is stored for max. 30 min in the traffic data memory (up to 100 messages), even during the COMAND shut-off delay period. The traffic data memory decodes the messages and relays them to the navigation processor if required. For synchronization the traffic data memory requires a current "location list " from the traffic data memory decodes the messages and relays them to the navigation processor if required. For synchronization the traffic data memory requires a current "location list" from the navigation processor .

The monitoring points for controlling the street network (e.g. highway exits), are defined with clear numbers in the " location list ".

The "location list " is stored on the CD-ROM . If required it is loaded automatically into the non-volatile traffic data memory by the navigation processor ( e.g. changing CD-ROM ).