GF82.61-P-4111TX Radio/Navigation Unit, Component Description

GF82.61-P-4111TX Radio/Navigation Unit, Component Description
- with CODE (525) MB Audio 50 APS radio

Component Identification:

Location
The radio control panel and navigation unit (A2/56) is installed in the center console.

Task
The radio control panel and navigation unit (A2/56) centrally controls the following systems:
^ Audio system (radio, audio CD)
^ Navigation system
^ with code (388) Portable CTEL UPCI [UHI] system
^ With code (813) Voice control system (VCS)
^ With code (819) CD changer (6-disc)
^ with CODE (810) Sound system

Design
The following items are integrated in the radio control panel and navigation unit (A2/56):
^ Display
^ CD drive
^ Operating unit for control of audio, navigation, and telematics functions
^ Central processor

Function
The buttons and switches of the control panel in the radio control panel and navigation unit (A2/56) are read in and supplied to the central computer. The button operations are processed further in the central computer and passed to the other system components via the Media Oriented System Transport (MOST) or the class B (interior) Controller Area Network bus (CAN-B) in the form of a Controller Area Network (data bus/CAN bus) (CAN) message. The radio control panel and navigation unit (A2/56) switches on when the user presses the ON button on the rotary/pushbutton switch.

The volume for the set audio source is regulated at the rotary switch. The function keys switch over to the audio source desired by the user.
3 fixed contrast settings can be retrieved for better perception of the display information.

Audio CD drive
Data can be read from the navigation CD or an audio CD can be played using the integrated CD drive.

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

Navigation processor and 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 antenna signals. It also calculates the vehicle's route after the destination has been entered. The navigation processor evaluates the satellite signals coming from the GPS antenna (A2/49a2) and uses them to calculate the position of the vehicle. For an initial position calculation, it is necessary to receive the signals from at least 4 satellites; after that, 3 receivable satellites are sufficient. If these conditions for position calculation are not met, only the number of satellites appears in the display.

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

The traffic data memory
The traffic data recorder is located in the radio control panel and navigation unit (A2/56). The received data is 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 the traffic data recorder requires a current "location list" from the navigation processor. The monitory points required for checking the road network (e.g. freeway exit) are defined by unambiguous numbers in the "location list". The "location list" is stored on the CD. It is loaded automatically into the traffic data recorder by the navigation processor as required.