In smaller greenhouses, a manual program opened and closed yourself could possibly be installed. These work easiest when the screen materials is supported by a track system.
Start time – when each morning will the screen system start operation
Stop time – 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 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 up or close placement under 
different conditions such as in early stages a Rack Drive For Greenhouse winter early morning to lessen thermal shock or during the summer to provide better shading. The gap measures and speed of motion can be controlled in some systems.
Time delay – below changeable weather conditions this avoids frequent starting and closing
Wind speed – To lessen heat loss, the screen can be closed early under high wind speed conditions
Snow detection – this may open the display screen and turn on heat when it starts to snow.
The typical system uses nylon monofilament or stainless 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 leading edge of the screen material. Control is usually either with a manual change or electronic controller.
Based on the above, the grower must enter the next parameters in to the controller:
A climate station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.
