In smaller sized greenhouses, a manual program opened and closed yourself could possibly be installed. These work simplest when the screen material is supported by 
a monitor system.
Start time – when in the morning will the display system start operation
Stop period – when in the afternoon will the display screen system stop operation
Light level – in what light strength will the screen become activated either to open or close
Maximum/minimum temperature – what exactly are the limits of temperature desired
Maximum/minimum humidity – What are the limitations of humidity desired
Gap positions – this models the percent open or close placement under different circumstances such as in early stages a winter morning to lessen thermal shock or through the summer to supply better rack drive for greenhouse china shading. The gap measures and speed of movement can be controlled in some systems.
Time delay – below changeable weather conditions this avoids frequent opening and closing
Wind speed – To reduce temperature loss, the screen could be closed early under high wind speed conditions
Snow detection – this may open the display screen and turn on heat when it starts to snow.
The typical system uses nylon monofilament or stainless steel cables to support the screen material. The screen material can either rest on top of 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 material. Control is usually either with a manual change or electronic controller.
Based on the over, 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.