In smaller sized greenhouses, a manual program opened and closed by hand could possibly be installed. These work easiest when the screen materials is supported by a monitor system.
Start time – when in the morning will the display system start operation
Stop period – when in the afternoon will the display screen system stop operation
Light level – at what light strength will the screen be activated either to open or close
Maximum/minimum temperature – what exactly are the limits of temperature desired
Maximum/minimum humidity – What exactly are the limitations of humidity desired
Gap positions – this sets the percent open up or close Motor Gearboxes For Greenhouse position under different conditions such as in early stages a winter morning to lessen 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 – under changeable climate this avoids frequent starting and closing
Wind speed – To reduce warmth loss, the screen could be closed early under high wind speed conditions
Snow detection – this may open the screen and turn on the heat when it starts to snow.
The typical system uses nylon monofilament or stainless cables to aid the screen materials. The screen material can either 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 techniques the industry leading of the screen materials. Control is certainly 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 weather station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.