In smaller sized greenhouses, a manual program opened and closed yourself could be installed. These work easiest when the screen materials is backed by a track system.
Start time – when each morning will the screen system start operation
Stop period – when in the afternoon will the display screen system stop operation
Light level – at what light strength 
will the screen be activated either to open up or close
Maximum/minimum temperature – what exactly are the limitations of temperature desired
Maximum/minimum humidity – What exactly are the limits of humidity desired
Gap positions – this models the percent open or close placement under different conditions such as in early stages a winter early morning to reduce thermal shock or during the summer to provide better shading. The gap guidelines and speed of motion can be Motor Gearboxes For Greenhouse controlled in a few systems.
Time delay – below changeable climate this avoids frequent opening and closing
Wind speed – To reduce warmth loss, the screen can be closed early below high wind speed conditions
Snow detection – this can open the display and turn on heat when it begins to snow.
The typical system uses nylon monofilament or stainless steel cables to aid the screen material. The screen material can possibly rest along with the network of cables or become suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that movements the industry leading of the screen materials. Control is certainly either with a manual switch or electronic controller.
Based on the above, the grower must enter the following parameters in to the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.