In smaller greenhouses, a manual program 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 in the morning will the Rack Drive For Greenhouse display 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 are the limits of humidity desired
Gap positions – this pieces the percent open up or close placement under different circumstances such as early on a winter morning to reduce thermal shock or during the summer to supply better shading. The gap guidelines and speed of movement can be controlled in a few systems.
Time delay – below changeable weather conditions 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 display and turn on the heat when it begins to snow.
The typical system uses nylon monofilament or stainless 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 movements the leading 
edge of the screen material. Control is definitely either with a manual change or electronic controller.
Based on the over, the grower is required to enter the following parameters in to the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.