In smaller greenhouses, a manual system opened and closed by hand could be installed. These work simplest when the screen Rack Drive For Greenhouse 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 – in what light intensity 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 pieces 
the percent open or close position under different circumstances such as early on a winter early morning to reduce thermal shock or through the summer to provide better shading. The gap techniques and speed of motion can be controlled in a few systems.
Time delay – under changeable climate this avoids frequent starting and closing
Wind speed – To reduce temperature loss, the screen could be closed early below high wind speed conditions
Snow detection – this may open the 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 material. 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 movements the industry leading of the screen materials. Control is usually either with a manual change or electronic controller.
Based on the over, the grower must enter the next parameters in to the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.