Displaying Time

Networking:

NOTE: The components identified with dotted lines are only relevant to vehicles with COMMAND (code 352).


General
For time measurement (time) a periodic process with a period of high accuracy (e.g. rotation of the earth, pendulum oscillation) is required. Accordingly an electrical clock signal of high frequency accuracy is required for an electronic clock. This (lock signal is mostly derived from the very constant mechanical vibrations of an oscillating quartz. A quartz (1) with a really high frequency (several MHz) is normally used. This frequency is then scaled down to the required frequency of 1/60 Hz with an electronic frequency scaler (2). The display (3) thus receives an electrical pulse to continue switching the display every minute.

Displaying time on vehicles without Comand
The electronic clock (A1p6) works according to the above process. In addition further electronics are required to set the time. Settings take place via the "settings" menu with the multifunction steering wheel pushbuttons:
- Scroll forward/back pushbutton (S110s1)
- System select/voice control pushbutton (S111s3)
- Pushbutton + and - specific function setting, volume control (S111s1)
These multifunction steering wheel pushbuttons are read in directly by the instrument cluster (A1).

Displaying time on vehicles with COMMAND (code 352)
On vehicles with COMMAND the instrument cluster (A1) takes over the time from the COMMAND operating, display and control module (A40/3). The time is therefore set there.
The time information is sent to the CAN/interior as a message from the COMMAND operating, display and control module (A40/3).
If the COMMAND equipment variant is coded in the instrument cluster (A1), the instrument cluster takes over this time information.
If GPS signals are received from the GPS antenna (A2/49a2), it is possible to change over from summer to winter time automatically.