In smaller greenhouses, a manual program opened and closed by hand could possibly be installed. These work simplest when the screen material is supported by a monitor system.
Start time – when each morning will the 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 be Rack Drive For Greenhouse 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 position under different circumstances such as early on a winter morning to lessen thermal shock or through the summer to provide better shading. The gap measures and speed of motion can be controlled in some systems.
Time delay – below changeable weather conditions this avoids frequent starting and closing
Wind speed – To reduce warmth loss, the screen can be closed early under high wind speed conditions
Snow detection – this can open the display and turn on the heat when it begins to snow.
The standard system uses nylon monofilament or stainless cables to aid the screen materials. The screen material can possibly 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 movements the industry leading of the screen materials. Control is usually either with a manual change or electronic controller.
Based on the above, the grower is required to enter the following parameters into the controller:
A climate station is needed to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.