In smaller sized greenhouses, a manual rack drive for greenhouse china system opened and closed yourself could be installed. These work easiest when the screen materials is backed by a monitor system.
Start time – when in the morning will the display screen system start operation
Stop period – when in the afternoon will the display screen system stop operation
Light level – in what light strength 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 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 early morning to reduce thermal shock or through the summer to supply better shading. The gap guidelines 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 high temperature loss, the screen could be closed early under high wind speed conditions
Snow detection – this may open the screen and turn on heat when it begins to snow.
The standard system uses nylon monofilament or stainless cables to support 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 movements the leading edge of the screen materials. Control is definitely either with a manual change or electronic controller.
Based on the above, the grower must enter the next parameters into the controller:
A climate station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.