In smaller greenhouses, a manual program opened and closed yourself could be installed. These work easiest when the screen materials is supported by a track system.
Start time – when each morning will the display screen system start operation
Stop period – when 
in the afternoon will the screen system stop operation
Light level – in what light intensity will the screen end up being activated either to open or close
Maximum/minimum temperature – what are the limits of temperature desired
Maximum/minimum humidity – What are the limitations of humidity desired
Gap positions – this sets the percent open or close position under different conditions such as in early stages a winter early morning to reduce thermal shock or during the summer to supply better shading. The gap steps and speed of movement can be controlled in a few systems.
Time delay – under changeable weather conditions this avoids rack drive for greenhouse china frequent starting and closing
Wind speed – To lessen high temperature loss, the screen could be closed early below high wind speed conditions
Snow detection – this may open the display screen and turn on the heat when it begins to snow.
The typical system uses nylon monofilament or stainless steel cables to aid the screen materials. The screen material can possibly rest on top of the network of cables or end up being suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that techniques the leading edge of the screen material. 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 weather station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.