In smaller sized greenhouses, a manual system opened and closed by hand could possibly be installed. These work simplest when the screen materials is supported by a monitor system.
Start time – when each morning will the display system start operation
Stop time – when in the afternoon will the display screen system stop operation
Light level – at what light intensity will the screen be activated either to open up or close
Maximum/minimum rack drive for greenhouse china temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What exactly are the limits of 
humidity desired
Gap positions – this models the percent open up or close placement under different circumstances such as early on a winter morning to lessen thermal shock or during the summer to provide better shading. The gap guidelines 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 lessen temperature loss, the screen can be closed early below high wind speed conditions
Snow detection – this may open the screen and turn on heat when it starts to snow.
The standard 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 be suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that moves the industry leading 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 in to the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.