In smaller greenhouses, a manual program opened and rack drive for greenhouse china closed by hand could be installed. These work simplest when the screen materials is backed by a track system.
Start time – when in the morning will the display system start operation
Stop time – when in the afternoon will the display system stop operation
Light level – in what light strength will the screen be activated either to open or close
Maximum/minimum temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What exactly are the limits of humidity desired
Gap positions – this units the percent open up or close position under different circumstances such as early on a winter morning to lessen thermal shock or during the summer to provide better shading. The gap techniques and speed of movement can be controlled in a few systems.
Time delay – below changeable climate this avoids frequent opening and closing
Wind speed – To lessen temperature loss, the screen could be closed early below high wind speed conditions
Snow detection – this can 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 either 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 either with a manual change or electronic controller.
Based on the over, the grower is required to enter the following parameters into the controller:
A weather station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.