Art. No. SC 1000 KNX
4.2.4.6.2 Astro and random function
Astro function
The astro function allows the control of a lighting or shading system depending on sunrise and
sunset and a limit time. The astro function can be activated or deactivated separately for each
switching time as a presetting in the ETS as well as subsequently via the switching time display
pages.
The time of the sunrise and sunset (astro time) is location-dependent and is calculated by the
device according to local geographic co-ordinates. These can be set in the "Timer" parameter
node of the ETS plug-in by the project planner. To simplify the configuration, the local
coordinates of the astro function are preset to near the centre of Germany. If the standard
coordinates are maintained, the device works with the coordinates for the city of Kassel
(51"19'N[51,31], 9"30'O[9,50] ). This location definition can be altered according to the place of
installation.
When the astro function is activated, the switching time set acts as a limit time. Whether the
limit time affects sunrise or sunset is evaluated by the device according to the set time. Times
between 00:00 and 11:59 are evaluated as sunrise and times between 12:00 and 23:59 as
sunset.
An astro function usually affects lighting (e.g. exterior lighting) or shading (e.g. roller shutters).
The behaviour of the device when processing the astro switching times varies according to
these applications. The ETS parameter "Astro" in the parameter node of a switching time
generally enables the astro function and defines the astro behaviour as follows...
-
Setting "Light":
Sunrise (switching times 00:00 - 11:59): if sunrise occurs before the set time (for example
in the summer months), then, at sunrise, the switching time command (e.g. external lighting
OFF) is sent to the bus. If sunrise occurs later (for example during the winter months), then
the switching time command is triggered at the set time at the latest.
Sunset (switching times 12:00 - 23:59): if sunset occurs after the set time (for example in
the summer months), then the switching time command (e.g. external lighting ON) is sent
to the bus at sunset. If sunset occurs earlier (for example during the winter months), then
the switching time command is triggered at the set time at the latest.
-
Setting "Blind/shutter":
Sunrise (switching times 00:00 - 11:59): if sunrise occurs after the set time (for example in
the winter months), then the switching time command (e.g. roller shutters UP) is only sent
to the bus at sunrise. If sunrise occurs earlier (for example during the summer months),
then the switching time command is triggered at the set time at the latest.
Sunset (switching times 12:00 - 23:59): if sunset occurs before the set time (for example in
the winter months), then the switching time command (e.g. roller shutter DOWN) is sent
directly to the bus at sunset. If sunset occurs later (for example during the summer
months), then the switching time command is triggered at the set time at the latest.
i
Astro times for sunrise and sunset can vary by several hours. As a result, a switching time
with an active astro function might affect the allocated KNX channel by another switching
time. The mutual influence of different switching times is not intercepted.
Example: a switching time is set to 17:00, astro function active (seasonal sunset between
16:00 and 22:00), an additional switching time is set to 19:00 -> In this case, the second
time (19:00) would be affected by the astro function. The channel commands of the
switching times are always executed in accordance with their set or calculated time. The
same would apply, if both switching times in the example had the astro function active.
i
The calculated astro time is dependent on the time of year. The internal system clock of the
device must be set with a valid time and current date in order for the astro function to work
properly.
Page 229 of 347
Software "Smart Control 501511"
Functional description
