Art. No. SC 1000 KNX
4.2.4.6 Timer switch
4.2.4.6.1 Definition, function and channel commands
Definition and function
The device has an integrated weekly timer. This can be configured by the ETS and using a
special timer display page. The timer has up to 8 switching times, which directly affect the
configured KNX channels (1...30) in the device and can handle the data formats Switching (1
Bit), Value 1 byte (incl. brightness value and position setting) and Value 2 byte. The timer does
not have its own communication objects. Telegrams are transmitted to the bus for the switching
times via the objects of the KNX channels. The timer can also handle channel functions that
affect the internal room temperature controller (operating mode switchover, setpoint shift). Thus,
the setpoint temperature of the controller can be influenced depending on the time of the day.
Additionally, it is possible to also activate a random function (see page 230) and an astro
function (see page 229) for brightness-dependent lighting or shading control in the morning or
evening twilight for each switching time.
The timer is controlled by the device's internal system clock (time and date of the operating
system). Consequently, a valid time and current date must be preset for the correct execution of
the switching times. The system clock can be set via the communication objects "D.Input Time"
(KNX DPT 10.001) and "D.Eingang Date" (KNX DPT 11.001) or via the system settings in the
administration area (see page 130).
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The device's internal system clock is designed as a real time clock (RTC) and is extremely
accurate. It is advisable to set the system clocks of all devices once a day, for example, by
a shared KNX time telegram during the night hours, so that that the timing of all devices is
synchronized even over a long period of time.
The system clock has its own energy storage. This will ensure that the clock keeps on
running interruption-free for at least 2 hours in the event of a power supply failure.
The real time clock has a calendar function. Depending on the date set, the day is
determined automatically by means of the internal calendar which is necessary for
processing the timer. The day transmitted in the KNX time telegram in compliance with
DPT 10.001 is irrelevant and is discarded by the device.
Switching times are allocated to KNX channels and can be configured down to the minute.
Weekdays can be freely specified for each switching time. The set weekdays specify on which
days of a calendar week the timer commands are to be executed. A switching time thus
consists of the time of day and weekday information.
At each minute mark - possibly offset by a few seconds - the timer checks the set switching
times. If a switching time corresponds to the current time (check for hours and minutes) and
current weekday, the preset channel command is executed. Different channel commands (e.g.
switching a lighting system on and off) require various switching times. Allocate KNX channels
to several switching times if possible. This makes it possible, for example, to configure exterior
lighting (e.g. channel 1) to be switched on in the evening (switching time 1) and to be switched
off again in the morning (switching time 2).
If a channel is allocated to several switching times with an identical configuration (the same time
and weekday), the channel command of the switching time with the highest number (1...8) will
always be executed.
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Switching times are not tracked if the set time or preset weekday was skipped as a result of
setting the system clock or power failure. Switching times are executed redundantly,
however, if the time is reset. Examples...
1. Current time: 11:59, set switching time: 12:00 -> The system clock is preset to 12:01. ->
The switching time was skipped and will not be repeated.
2. Current time: 12:00, set switching time: 12:00 -> The switching time is executed on
time. -> The system clock is reset to 11:59. -> The switching time is executed again at
12:00.
3. Current time: 11:59, current weekday: Monday, set switching time: 12:00, Monday ->
The date of the system clock is changed so that the next weekday (Tuesday) is active. ->
The switching time was skipped and will not be repeated.
Page 226 of 347
Software "Smart Control 501511"
Functional description
