GF82.85-P-3114-08P Operating, Display Unit With Control Unit, Function
GF82.85-P-3114-08P Operating, Display Unit With Control Unit, Function
- with CODE (352a) COMAND operating and display system
- except CODE (491) U.S. version
- except CODE (498) Japanese version
Processing button actuations
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 button presses are processed in the central computer or notified over the Digital Data Bus (D2B), Controller Area Network bus Class B (interior) (CAN-B) or Robert Bosch CAN (RB CAN) in the form of a data telegram to the other system components.
Graphic editing and image output
The video subsystem takes over editing and output of the control displays. The operating masks are internally output to the display by the graphics subsystem via the RGB signal output (R=red, G=green, B=blue).
The information and amplitudes of the 3 primary colors red, green and blue as well as a synchronization signal are included in the RGB signal.
The electronic circuitry in the display unit evaluates the RGB signal and controls the individual display dots 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. Upon reaching the last line the vertical synchronization pulse is received causing the electronic circuitry to start the first line again.
Audio signal output
The audio signals from the various sources (e.g. Compact Disc (CD), navigation voice output) are prepared by the COMAND operating, display and control unit (A40/3n1) and amplified before being output via the vehicle speakers. For 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 are digitally transferred to the sound amplifier (A2/13).
Info menu as of 1.6.01
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). The screen from which the information was selected can be returned to by means of the "Return" key.If the Mode option was selected in the Information menu, the system switches to the screen preceding the Information menu when the "Return" key is pressed.
Diagnosis interface and error administration
While the COMAND operating, display and control unit (A40/3) is active, the system stores all faults that occur in the non-volatile memory. These can be read out via the diagnosis interface with the aid of STAR DIAGNOSIS. Output of the errors on the display unit is not possible. The error administration also includes the components connected to the Digital Data Bus (D2B). Each D2B component has its own DTC memory. On request the errors are transmitted by STAR DIAGNOSIS via D2B to the COMAND operating, display and control unit (A40/3).
There they can be read out over the diagnosis interface.
Navigation processor and GPS control unit.
The navigation processor is the central component of the navigation system. It is integrated in the COMAND operating, display and control unit (A40/3) and calculates the location of the vehicle from the incoming signals. It also calculates the vehicle's route after the destination has been entered.
The global positioning system (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
At least 4 satellites are required for dead reckoning, 3 satellites are sufficient for other calculations. If these conditions for position calculation are not met, only the number of satellites appears in the display.
CD and CD drive
With the aid of the integrated multi-standard drive, data can be read from the special navigation CD or audio CDs can be played. The following data are located on the Navigation CD:
^ Program data for execution in navigation processor
^ Voice data for voice output
^ Map data.
Note in Navigation screen:
Up to 31.5.01: "Please insert navigation CD". As from 1.6.01: "Please insert navigation CD type DX".
This notice is intended to ensure that the customer inserts the correct CD.
The digitized map area on the navigation CD contains towns, cities, streets, intersections and their attributes (e.g.: one-way streets, turn prohibitions, etc.). 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 the D2B (for TCS mode) or internally by the radio tuner (for TMC mode). The data are stored for a maximum of 30 min in the traffic data recorder, including during the run-on time of the COMAND operating, display and control unit (A40/3). The traffic data recorder 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 monitoring points for checking the road network (e.g. freeway exit) are defined by unique numbers in this list. The "Location list" is stored on the Navigation CD. It is automatically loaded (e.g. if CD is changed) from the navigation processor into the traffic data recorder.
Gyrosensor
The yaw rate sensor is installed in the navigation processor and detects any directional changes of the vehicle. Calibration is not required.