Display Time, Function - GF54.30-D-3024HH

MODEL 906 with CODE (JK3) High-end instrument cluster with speedometer in km 

General information 

Time measurement (clock) requires a periodic process with a cycle duration of high accuracy (e.g. earth rotation).

Similarly, an electrical clock signal with high frequency accuracy is required for the electronic clock in the display (A1p1) of the instrument cluster (A1). This clock signal is usually derived from the very constant, mechanical vibrations of an oscillator crystal.

An oscillator crystal with a very high frequency (several MHz) is normally used. This frequency is then scaled down to the required frequency of 1 Hz using a frequency scaler with control electronics. In this way, the electronic clock receives one electrical pulse every second to change the display.

Setting time on vehicles except code (EN4) COMAND with TMC interface and except code (EN8) Sound 50 APS radio 

The electronic clock is set via the "Settings" menu in the display of the instrument cluster using the following buttons on the multifunction steering wheel (MFL):

• System selection button (S111s3)
• Scroll forward/back button (S111s1)
• + and - button (S110s1)

The buttons on the MFL are read in by the MRM control unit (N80) and passed on to the instrument cluster via the Controller Area Network bus class B (interior) (CAN-B).

The electronic clock can also be adjusted using STAR DIAGNOSIS.

Setting time on vehicles with code (EN4) COMAND with TMC interface and with code (EN8) Sound 50 APS radio 

On these vehicles, the instrument cluster adopts the time from the radio/radio with navigation (N87/1). The radio with navigation provides a precise time signal by adopting the global positioning system (GPS) time from the navigation system. In this case, some of the menus for setting the time are unnecessary and are omitted.

The radio with navigation places the time information on CAN-B in the form of a message.

The instrument cluster reads in the time information from CAN-B and uses this information to display the electronic clock in the display.