In smaller sized greenhouses, a manual system opened and closed yourself could possibly be installed. These work easiest when the screen material is backed by a monitor 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 or close
Maximum/minimum temperature – what are the limits of temperature desired
Maximum/minimum humidity – What are the limits of humidity desired
Gap positions – this pieces the percent open or close placement under different conditions such as in early stages a winter morning to reduce thermal shock or during the summer to provide better shading. The gap measures and speed of movement can be controlled in a few systems.
Time delay – under changeable weather conditions this avoids frequent opening and closing
Wind speed – To lessen warmth loss, the screen can be closed early under high wind speed conditions
Snow detection – this may open the display and turn on the heat when it starts to snow.
The typical system uses nylon monofilament or stainless steel cables to aid the screen material. The screen material can either rest along with 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 materials. Control is usually either with a manual switch or electronic controller.

Based on the above, the grower is required to enter the next parameters into the controller:

A weather station is required to provide Motor Gearboxes For Greenhouse outdoor light level, temperature, humidity, wind and rain or snow conditions.