curtain control by light level sensor

There are a few blinds/curtains to be controlled by either Light level sensor or Multisensor.

The idea is simply close the blind when the sun is too bright. We don't want it to open the blind if it is darker however, otherwise the blind may close and open regularly. When it is closed by sensor and client wants to override and open it, can he do it by pressing only one button (open key) rather than needing to disable the sensor and open the blind? Also we need to avoid it triggered by in-house lighting in the evening. Is there any common programming solution for applications like that?

 

How others do it

Hi there,

I can't say how it is done in C-bus, but a few thoughts upfront:

In other systems, they put a delay time between reaching the sun level and actually running the blinds down. This means the sun level needs to be exceeded between 5-15 minutes before operation. If it falls below the threshold in between, the counter is reset.
The same goes for up: There is usually a delay time, when brigthness is too low, it doesn't bring the blinds up immediately, but with delay time between 10-30 minutes.
There is on other big consideration why a delay time is useful:
The blind motors are not designed for continuous running. If you run them up and down constantly, they will overheat and a built in thermostat will cut power to the motors after about 4-6 minutes time. (The thermal protector will re-engage automatically after about 5-30 minutes cool-down time)

Hope this helps!