In smaller greenhouses, a manual system opened and closed by hand could be installed. These work simplest when the screen Motor Gearboxes For Greenhouse materials is backed by a monitor system.
Start time – when in the morning will the screen system start operation
Stop time 
– when in the afternoon will the display 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 exactly are the limitations of humidity desired
Gap positions – this units the percent open or close placement under different conditions such as in early stages a winter morning to lessen thermal shock or through the summer to provide better shading. The gap methods and speed of motion can be controlled in a few systems.
Time delay – under changeable climate this avoids frequent opening and closing
Wind speed – To lessen warmth loss, the screen could be closed early below high wind speed conditions
Snow detection – this can open the screen and turn on heat when it starts to snow.
The standard system uses nylon monofilament or stainless cables to support the screen material. The screen material can either rest on top of 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 can be either with a manual switch or electronic controller.
Based on the over, the grower is required to enter the following parameters in to the controller:
A weather station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.