
Switch/shutter actuator 8/4gang 16A RMD
75318003
Switch/shutter actuator 16/8gang 16A
RMD
75310002
Technical
Documentation
© Berker GmbH & Co KG 2007
Version: 04.04.2007
Part 5
(Subject to prior change)
75310002.doc
Seite: 79 / 174
Calculating the slat position (only with blinds)
In the "blinds" mode of operation, the switching/shutter actuator always calculates the slat position so that
the opening angle and thus the amount of light admitted into the room by the blind can be adjusted. A new
position approach by a blind will always be followed by a positioning movement of the slats. Thus, the slat
positions last selected will be tracked or readjusted to a new value if a position change has taken place.
In case of single-motor blind drive systems with working position, the slats will be readjusted directly by a
change of the blind curtain height. For this reason, an adjustment of the slat position will always have an
influence on the position of the blind itself (cf. Fig. 27).
blind = 40 %
0%
50%
parameterized slat moving time
insolation
Sun
100%
blind = 45 %
blind = 50 %
desired blind position
Fig. 27: Example of slat positioning affecting the position of the blind
(typical of slat type 1; analogous reaction for type 2)
Since a preset slat position is to remain constant until the next change, the actuator will not change the
height of the blind, if the calculated travelling time required for a change of position lies within the
parameterized slat moving time.
Similarly, the actuator accounts for the ratio of the moving times of slat and blind and – in case of slat
position changes – always recalculates the resulting blind position. If the position feedback objects are used
(cf. "Position feedback"), the actuator transmits the blind positions changed by the adaptation also to the
bus.
Example (cf. Fig. 27)…
The blind position is preset to 50 %. A change of the slat angle (100 %...0 %) initiates the calculation of a
new blind position which is also tracked in the position feedback objects. If the actuator is to approach a
new blind position of, let's say 47 % in this case, the actuator will not perform a travel movement as the
calculated travelling time lies within the parameterized slat moving time and therefore coincides with the slat
movement. A change of the blind position to 55 % in this case triggers a blind movement as the change
does not lie within the slat movement (0 to 100 %).
For each positioning movement, the desired blind position is referred to a slat position of 100 %. In the
event of a slat re-positioning movement (0 to 100 %), the actuator will therefore report a blind position below
the desired position.