In smaller greenhouses, a manual system opened and closed by hand could be installed. These work simplest when the screen material is supported by a track system.
Start time – when in the morning will the display system start operation
Stop period – when in the Rack Drive For Greenhouse afternoon will the screen system stop operation
Light level – at what light strength will the screen end up being 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 pieces the percent open up or close position under different conditions such as early on a winter morning to reduce thermal shock or through the summer to provide better shading. The gap methods and speed of movement can be controlled in a few systems.
Time delay – below changeable weather conditions this avoids 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 can open the display and turn on the heat when it begins to snow.
The typical system uses nylon monofilament or stainless steel cables to support the screen materials. The screen material can possibly rest along with the network of cables or end up being suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that moves the leading edge of the screen materials. Control is definitely either with a manual change or electronic controller.
Based on the over, the grower must enter the next parameters into the controller:
A weather station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.