Displaying time, function - GF54.30-P-3024PP
MODEL 203.0 /2 /7 up to 23.4.04
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 (1) 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 (2). In this way, the electronic clock (A1p6) (3) receives one electrical pulse every second to change the display.
Displaying the time in vehicles except code (352a) COMAND operating and display system
The electronic clock (A1p6) works according to the adjacent principle. Additional electronics are also needed to set the clock. The electronic clock 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)
The instrument cluster (A1) also passes the current time as a message on the class B (passenger compartment) controller area network bus (CAN-B).
Valid up to 30.6.02
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 EIS [EZS] control unit (N73) and passed to the instrument cluster (A1) on the class B (passenger compartment) controller area network bus (CAN-B).
Valid as of 1.7.02
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).
Displaying 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 transmitted by the COMAND operating, display and control unit (A40/3) as a message on CAN-B.
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.
| Instrument cluster (IC), location/task | GF54.30-P-3039PP |