Displaying time, function - GF54.30-P-3024PM
MODEL 203.0 /2 /7 as of 24.4.04
General information
Time measurement (clock) requires a periodic process with a cycle duration of high accuracy (e.g. earth rotation, pendulum oscillation). Likewise, an electronic clock requires an electric clock signal with high frequency accuracy. 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 (A1p6) receives one electrical pulse every second to change the display.
If the limiter function is not activated, the time is displayed in the lower part of the multifunction display (A1p13). If the limiter function is activated, the time is displayed in the upper part of the multifunction display (A1p13).
Setting the time in vehicles except code (352a) COMAND operating and display system
The electronic clock (A1p6) is set using the "Settings" menu in the multifunction display (A1p13) using the following buttons of the multifunction steering wheel:
- Scroll forward/back button (S110s1)
- System selection button (S110s3)
- + and -, setting specific functions and volume control button (S111s1)
Setting the time in vehicles with code (352a) COMAND operating and display system
In these vehicles, the instrument cluster (A1) adopts the time from the COMAND operating, display and control unit (A40/3). The menus for adjusting the time are therefore unnecessary.
The time information is sent as a message on the class B (passenger compartment) controller area network bus (CAN-B) by the COMAND operating, display and control unit (A40/3).
If the code for COMAND operating, display and control unit (code 352a) has been entered in the instrument cluster (A1), it assumes this time information.
If the GPS antenna (A2/23) is receiving GPS signals, these can be used to switch between summer and winter time automatically.
The scroll forward/back button (S110s1), the system selection button (S110s3) and the + and -, setting specific functions and volume control button (S111s1) are read in by the steering column module (N80) and passed to the instrument cluster (A1) on the class B (passenger compartment) controller area network bus (CAN-B).
The instrument cluster (A1) also passes the current time on CAN-B in the form of a message.
| Instrument cluster (IC), location/task | GF54.30-P-3039PM |