Displaying time, function - GF54.30-P-3024S
Model 215, 220
Networking of components:
General:
Time measurement (clock) requires a periodic process with a cycle duration of high accuracy (e.g. earth rotation, pendulum oscillation).
Likewise, an electronic clock (A1p6) requires an electric clock signal with high frequency accuracy. This clock signal is usually derived from the extremely constant mechanical oscillations of an oscillator crystal. A quartz with a very high frequency (several MHz) is normally used. This frequency is then scaled down to the required frequency of 1 Hz using an electronic frequency scaler. The display thus receives an electrical pulse to switch the display every second.
Displaying time on vehicles without Command:
The electronic clock (A1p6) works according to the principle described above.
Electronics are also required to set the clock.
The driver can set the clock in the "Settings" menu using the buttons on the multi-function steering wheel:
- Scroll forward/back button (S110s1)
- System selection button (S110s3)
- + and - button, specific function setting and volume control (S111s1)
The signals from these buttons are registered by the steering column module (N80) and relayed to the instrument cluster (A1) via the interior compartment CAN.
(For further information see Operating Instructions)
Displaying time on vehicles with Command:
On vehicles with COMAND, the instrument cluster (A1) uses the time information from the COMAND control unit. The current time is received via the GPS antenna (A2/49a2) and passed on to the COMAND control unit.
The time information is transferred from the COMAND control unit to the interior compartment CAN every minute as a message.
If the COMAND variant is coded in the instrument cluster (A1), the instrument cluster adopts this time information.
If GPS signals are received from the telephone and GPS roof antenna (A2/49), these signals can be used to switch automatically between summer and winter time.
Adjustments for different time zones are also automatic. COMAND system receives local information via GPS.
The components indicated by the broken lines in the networking diagrams are only relevant for vehicles with the COMAND operating and display system (Code 352a).
The instrument cluster (A1) also outputs the current time as a message via the interior compartment CAN.
| Instrument cluster (IC), location / task | GF54.30-P-3039S |