In smaller greenhouses, a manual system opened and closed yourself could be installed. These work easiest when the screen material is backed by a monitor system.
Start time – when each morning will the screen system start operation
Stop time – when in the afternoon will the display screen system stop operation
Light level – at what light strength will the screen become activated either to open or close
Maximum/minimum temperature – what exactly are the limitations of temperature desired
Maximum/minimum humidity – What are the limitations of humidity desired
Gap positions – this pieces the percent open or close position under different circumstances such as early on a winter early morning to lessen thermal shock or during the summer to supply better rack drive for greenhouse china shading. The gap methods and speed of movement can be controlled in a few systems.
Time delay – under changeable climate this avoids frequent starting and closing
Wind speed – To reduce high temperature loss, the screen can be closed early below high wind speed conditions
Snow detection – this can open the screen and turn on heat when it starts to snow.
The typical system uses nylon monofilament or stainless steel cables to support the screen materials. The screen material 
can possibly 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 techniques the industry leading of the screen materials. Control is certainly either with a manual switch or electronic controller.
Based on the over, the grower must enter the next parameters into the controller:
A climate station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.