GF82.61-P-4109-04T Radio and Navigation Unit, Function

GF82.61-P-4109-04T Radio And Navigation Unit, Function
- with CODE (525) MB Audio 50 APS radio


Processing button actuations
The control buttons and switches on the function keypad in the radio control panel and navigation unit (A2/56) are read in over the microcontroller I/O ports and transferred to the central processor. Depending on the system function, the button actuations are processed in the central computer or transmitted to the other system components via the Media Oriented System Transport (MOST), the Controller Area Network bus class B (interior) (CAN-B) or the Controller Area Network bus class C (engine compartment) (CAN-C) in the form of a data telegram.
If the ON/OFF button on the rotary switch is pressed, the radio control panel and navigation unit (A2/56) switches on. The volume is regulated at the rotary switch for the audio source adjusted in each case. The function keys switch over to the audio source desired by the user.

Graphic editing and image output
The graphics subsystem handles the preparation and output of the operating masks.
The operating masks are internally output to the display by the graphics subsystem via the RGB output (R=red, G=green, B=blue). The RGB signal contains the information and amplitudes of the 3 colors, red, green and blue as well as a synchronization signal. The electronic circuitry in the display unit evaluates the RGB signal and actuates 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 electronics of the radio control panel and navigation unit (A2/56) thereupon actuate the next line. When the last line of the display has been reached, the vertical synchronization pulse follows. The electronics actuate the 1st line again.

Three fixed contrast settings can be called up on the display:
^ Day design
^ Night design
^ Driving lights

Continuous brightness adjustment is possible via the cross-shaped rocker button.

Multistandard drive for audio CD and MP3-CD-ROM
With the aid of the integrated multistandard drive, data can be read from the special navigation CD or audio CDs can be played.

After inputting the destination (the data required are read into the memory) it is possible to change the navigation CD for a music CD and listen to music.

AUX jack
Additional audio sources such as an MP3 player can be integrated in the front entertainment system via the AUX jack. The AUX jack is located in the glove compartment.

Navigation CD
The following are on the navigation CD:
^ Program data for execution in navigation processor
^ Voice data for voice output
^ Map data.

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 on the display.

Off-board diagnosis, STAR DIAGNOSIS
The radio control panel and navigation unit (A2/56) has its own diagnostic trouble code memory. When the fault memory is queried by means of STAR DIAGNOSIS, the data are transmitted to the audio gateway control unit (N93/1) via the MOST and can then be read out via the central gateway control unit (N93). It is not possible to output the faults via the radio control panel and navigation unit (A2/56).

Navigation processor and global positioning system (GPS) control unit
The navigation processor is integrated into the radio control panel and navigation unit (A2/56) 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 a part of the navigation processor. It evaluates the satellite signals coming from the GPS antenna (A2/23) (model 211.2), from the GPS antenna (A2/49a2) (model 211.0) for vehicles up to 30.6.06 or from the GPS antenna (A2/49a2) for vehicles as of 1.7.06 and calculates from them the vehicle location.

Turn rate sensor
The turn rate sensor determines the direction changes of the vehicle. It is installed into the navigation processor. A calibration is not required.

The traffic data memory
The traffic data recorder is located in the radio control panel and navigation unit (A2/56). In RDS/TMC mode, the uncoded traffic report data received by the radio tuner in the audio gateway control unit (N93/1) are transmitted to the traffic data recorder via the MOST. The data are stored for a maximum of 30 minutes, also during the "run-on time" (up to 100 messages). The traffic data memory decodes the messages and transmits them to the navigation processor as required. For synchronization tasks, the traffic data recorder requires an up-to-date "location list" from the navigation processor.

The monitoring points for checking the network of roads (e.g. freeway exit) are defined by clear numbers in the "location list". The "location list" is stored on the CD-ROM. It is automatically loaded (e.g. if CD-ROM is changed) from the navigation processor into the traffic data recorder.