The AlarmClock uses a DCF77 receiver module to get the current official German standard time from a wireless transmitter located near Frankfurt, Germany.
Synchronization takes place on every 58th minute in the hour. If after five
minutes of trying no correct time signal has been received or decoded, an
error counter is increased and the receiver is turned off until the next
hour. The display shows
rcv in the top line when the DCF77 signal
reception is active. Between successful synchronizations and when the clock
is powered off, a high-precision, battery buffered real time clock chip
takes care of timekeeping.
Two alarm modes can be used: The first one, called absolute alarm mode, lets
the user set a specific time (e.g. "at seven in the morning"). When this
time has come, and the clock is powered on, the alarm goes off. This alarm
mode is marked with an at
@ symbol before the alarm time, if this is
Using the second mode, called relative alarm mode, the user can set a time
duration, like "seven hours from now". "Now" here means the moment the
alarm is activated. Using this mode, a user can program the clock to let
him sleep for a defined amount of time, given that the alarm is turned on
when going to bed. In this mode, the alarm time is marked with a plus (
Once the alarm rings, the user can decide either to turn it off by dialing the number given in the clock's display, or shortly lift and place back the handpiece to activate snooze mode. In this mode, the alarm will be turned off, and start ringing again after five minutes. After a configurable number of snooze actions, though, the snooze function will be deactivated and the alarm will sound until it is turned off through the respective menu function.
When turned on and in normal operations, the clock displays in the four display lines the following things.
00should be displayed there. When the DCF77 receiver is active, the string
rcvis displayed in front of the sync error counter.
When the clock display is active, as well as in any other screen mode, the display backlight can be turned on by lifting the telephone handpiece. Backlight will then turn on for up to about six seconds after the handpiece has been placed down again, and turn off then. When the alarm is ringing, the backlight is automatically switched on until the alarm is turned off.
All further instructions assume that the clock display is currently being
shown. If any other display is activated, the user should follow the
instructions given in the respective documentation section to get back to
the clock display. Dialing
1 always brings the user one menu level
1 from the time display opens the alarm configuration menu.
To enter a new alarm time, the user can now choose between absolute and
relative alarm mode. Dialing
4 activates relative alarm (marked
on the display), dialing
AbsTime) lets the user enter an
absolute alarm time.
Adjust), a new alarm time can be entered by dialing
it in the format HH:MM, as displayed.
When either the alarm mode has been changed or a new alarm time was entered,
the alarm is automatically turned off if it was on. It can be manually
toggled on and off again by dialing
On/Off) in the alarm
configuration menu. In relative alarm mode, the timer starts to run when
the alarm is switched on, and is reset when the alarm is switched off. The
remaining time until the alarm rings is displayed in the second display
The alarm clock remembers the last alarm settings for both relative and absolute alarm mode, and remembers them separately for weekdays and weekend mornings: when an alarm is set on Sunday to Thursday, it is stored in the "weekday" memory, on Friday and Saturday, alarm settings are written to the "weekend" storage.
1 returns to the time display.
5 from the time display, the configuration menu is opened.
Here, the following options can be configured by dialing the respective
3 Turns automatic synchronization with the DCF77 time signal on and off.
If turned on, the clock activates the receiver on the 58th minute of every
hour, and updates the internally kept time with the received one.
4 Initiates a DCF77 synchronization manually. The same timeout rule as
for the automatic reception applies, but on failure, the error counter is
5 Lets the user dial in the maximum allowed number of snooze actions.
6 Displays diagnostic and firmware version information.
1 Switches back to time display.