In smaller greenhouses, a manual program opened and closed yourself could possibly be installed. These work simplest when the screen material is supported by a monitor system.
Start time – when in the morning will the 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 be activated either to open or close
Maximum/minimum temperature – 
what are the limitations of temperature desired
Maximum/minimum humidity – What are the limits of humidity desired
Gap positions – this pieces the percent open up or close position under different circumstances such as in early stages a winter morning to lessen thermal shock or during the summer to supply better shading. The gap techniques and speed of movement can be controlled in some systems.
Time delay – under changeable weather conditions this avoids frequent opening and closing
Wind speed – To reduce high temperature loss, the screen can be closed early below high wind speed conditions
Snow detection – this may open the display screen and turn on heat when it begins to snow.
The standard 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 become 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 certainly either with a manual change or electronic controller.
Based on the above, the grower must enter the following parameters in to the controller:
A climate station is required to provide Motor Gearboxes For Greenhouse outdoor light level, temperature, humidity, wind and rain or snow conditions.