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

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

Processing button actuations
The control buttons and switches on the function keypad in the COMAND operating, display and control unit (A40/3) are read in over the microcontroller I and O ports and transferred to the central computer. Depending on the system function, the keys presses 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 basic 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. There is a pulse at the end of each line which 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 restarts at the first line again.

Diagnostic interface and error management
While the COMAND operating, display and control unit (A40/3) is active, the system stores all faults occurred in the non-volatile 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 errors are transmitted on request by STAR DIAGNOSIS via MOST to the audio gateway control unit (N93/1) and can then be read out.

Digital versatile disk (DVD)-ROM drive
Audio CDs, video DVDs or MP3s can be played with the aid of the integral DVD-ROM drive.

The traffic data memory
The integral traffic data recorder receives the traffic messages via MOST from the radio tuner in the audio gateway control unit (N93/1). The data is stored for a maximum of 30 minutes in the traffic data recorder (up to 100 messages) even 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 (N41/1) as required.

The traffic data recorder requires an up-to-date "location list" from the navigation processor (N41/1) for synchronization purposes. The monitory points required for checking the road network (e.g. freeway exits) are defined by unambiguous numbers in this list. This "location list" is stored on the navigation DVD. It is loaded when needed (e.g. if DVD is changed) from the navigation processor (N41/1) into the traffic data recorder.