In smaller greenhouses, a manual system opened and closed by hand could be installed. These work easiest when the screen materials is supported by a track system.
Start time – when in the morning will the rack drive for greenhouse china display system start operation
Stop time – when in the afternoon will the screen system stop operation
Light level – at what light intensity will the screen become activated either to open up or close
Maximum/minimum temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What exactly are the limitations of humidity desired
Gap positions – this pieces the percent open or close placement under different conditions such as early on a winter morning to lessen thermal shock or during the summer to supply better shading. The gap measures and speed of motion can be controlled in a few systems.
Time delay 
– below changeable weather conditions this avoids frequent opening and closing
Wind speed – To reduce high temperature loss, the screen could be closed early under high wind speed conditions
Snow detection – this can open the screen and turn on heat when it begins to snow.
The typical system uses nylon monofilament or stainless cables to support the screen material. The screen material can either rest along with the network of cables or become suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that techniques the industry leading of the screen materials. Control is usually either with a manual switch or electronic controller.
Based on the over, the grower must 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.