In smaller sized greenhouses, a manual program opened and closed by hand could be installed. These work easiest when the screen material is backed by a monitor system.

Start time - when each morning will the display screen system start operation
Stop time - when in the afternoon will the screen system stop operation
Light level - at what light intensity will the screen become activated either to open or close
Maximum/rack drive for greenhouse china minimum temperature - what are the limitations 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 during the summer to provide better shading. The gap guidelines and speed of motion can be controlled in a few systems.
Time delay - under changeable weather conditions this avoids frequent opening and closing
Wind speed - To reduce heat loss, the screen could be closed early below high wind speed conditions
Snow detection - this may open the display and turn on the heat when it begins to snow.
The standard system uses nylon monofilament or stainless steel cables to support the screen material. The screen material can possibly rest on top of the network of cables or become suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that techniques the leading edge of the screen material. Control is definitely either with a manual switch or electronic controller.

Based on the over, the grower is required to enter the following parameters into the controller:

A climate station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.