Displaying time function - GF54.30-P-3024B

MODEL 208 as of 1.8.99, 210 as of 1.7.99 

Networking 

The components identified with dotted lines are only relevant to vehicles with COMAND (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 clock 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 Command 

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 push-buttons:

• Scroll forward/back pushbutton (S110s1)
• System select/voice control pushbutton (S110s3)
• Pushbutton + and -, specific function setting, volume control (S111s1)

  These multifunction steering wheel push-buttons are read in directly by the instrument cluster (A1).

  (For more details, see operating instructions)

Displaying time on vehicles with COMAND (code 352) 

On vehicles with COMAND the instrument cluster (A1) takes over the time from the COMAND 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 COMAND operating, display and control module (A40/3).

If the COMAND 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.

	Instrument cluster, operating instructions		GF54.30-P-0002-05B
	Liquid crystal display (LCD), location/task/ function		GF54.30-P-3015A
	Quartz, location/task/function	Oscillator crystal	GF54.30-P-3017A
	Cockpit Management and Data System (COMAND), function	On vehicles with Command (code 352) only	GF82.85-P-0003C