In smaller sized greenhouses, a manual program opened and closed by hand could possibly be installed. These work simplest when the screen material is supported by a track system.
Start time – when in the morning will the display screen system start operation
Stop period – when in the afternoon will the display system stop operation
Light level – at what light intensity will the screen end up being activated either to open up or close
Maximum/minimum temperature – what exactly are the limits of temperature desired
Maximum/minimum humidity – What are the limits of humidity desired
Gap positions – this sets the percent open or close placement under different conditions such as early on a winter early morning to reduce thermal shock or during the summer to provide better shading. The gap steps and speed of movement can be controlled in some systems.
Time delay – below changeable weather conditions this avoids frequent starting and closing
Wind speed – To lessen warmth loss, the screen can be closed early under high wind speed conditions
Snow detection – this can open the screen and turn on the heat when it begins to snow.
The standard system uses nylon monofilament or stainless steel cables to aid the screen materials. The screen material can possibly rest along with the network of cables or end up being suspended by hooks from the cables. 
A gearmotor powers a drum or rack and pinion that techniques the industry leading of the screen material. Control is certainly either with a manual Rack Drive For Greenhouse switch or electronic controller.
Based on the above, the grower is required to enter the next parameters into the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.