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

GF82.85-P-3114-08QMU Operating, Display Unit With Control Unit, Function
- with CODE (530) COMAND APS USA (with navigation system)


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 a microcontroller and transferred to the central processor.
Depending on the system function the key actuations in the central computer are further processed or notified over the Media Oriented System Transport (MOST) and the Controller Area Network Bus Class B (interior) (CAN-B) 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 displayed internally over the graphic subsystem via the color image blanking synchronous (FBAS) signal input to the display of the COMAND operating, display and control unit (A40/3). The information and amplitudes of the 3 primary colors red, green and blue as well as a synchronization signal are included in the FBAS signal.

The control electronics in the display unit evaluates the signal and controls the individual pixels line by line in terms of color and intensity. A pulse is emitted at the end of each line, which synchronizes the horizontal picture signal. The electronic circuitry of the display unit then starts the next line. After reaching the last line of the display, a pulse is issued which synchronizes the vertical picture signal and the control electronics starts the first line again.

Audio signal output
The audio signals from the various sources (CD, navigation system voice output etc.) are prepared by the COMAND operating, display and control unit (A40/3n1) and amplified before being output via the vehicle loudspeakers. Final amplification of the audio signals is accomplished by the sound amplifier (A2/13). For this purpose, the audio source data is digitally transferred to the sound amplifier (A2/13).

Diagnosis interface and error management for MOST components
While the COMAND operating, display and control unit (A40/3) is active, the system stores all occurring faults in a non-volatile memory. This data can be read out using STAR DIAGNOSIS. Output of the errors on the display unit is not possible. The fault management also includes the components connected to the MOST bus.Each MOST component has its own fault memory. The faults are sent when requested by the STAR DIAGNOSIS over the MOST to the COMAND operating, display and control unit (A40/3) where they can then be read out via the data link connector (X11/4).

Navigation processor and global positioning system (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 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.

Digital Versatile Disk (DVD) and DVD ROM disk drive
Data can be read from the special navigation DVD or audio CDs played using the integrated DVD ROM drive. The following information is on the navigation DVD:
^ Program data for execution in navigation processor
^ Voice data for voice output
^ Map data.

The digitized map area on the DVD ROM comprises 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.

Gyrosensor
The gyrosensor determines the direction changes of the vehicle. It is installed in the navigation processor of the COMAND operating, display and control unit (A40/3). Calibration is not required.

The traffic data memory
The integrated traffic data recorder receives traffic messages via the MOST (in the StarGuide mode). Incoming data is stored for a max. 30 min., including during the run-on time of the COMAND operating, display and control unit (A40/3), in the traffic data recorder (up to 100 messages).

The traffic data memory decodes the messages and transfers them to the navigation processor as required. For synchronization purposes, the traffic data recorder requires a current "location list" from the navigation processor.In this location list, each stretch and each major point (e.g. freeway exit) of the road system which is monitored in respect of traffic density, is unequivocally defined on the basis of a number. The list is originally stored on DVD. It is automatically loaded (e.g. if DVD-ROM is changed) from the navigation processor into the non-volatile traffic data memory.