In smaller greenhouses, a manual system opened and closed by hand could be installed. These work simplest when the screen Rack Drive For Greenhouse material is backed by a track system.
Start time – when each morning will the screen system start operation
Stop time – when in the afternoon will the display screen 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 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 morning to reduce thermal shock or during the summer to provide better shading. The gap measures and speed of movement can be controlled in a few systems.
Time delay – below changeable weather conditions this avoids frequent opening and closing
Wind speed – To lessen warmth loss, the screen can be closed early under high wind speed conditions
Snow detection – this may open the display and turn on the heat when it starts to snow.
The standard system uses nylon monofilament or stainless 
cables to aid the screen material. The screen material can possibly rest along with the network of cables or become suspended by hooks from the cables. A gearmotor powers a drum or rack and pinion that moves the leading edge of the screen materials. Control is usually either with a manual switch or electronic controller.
Based on the over, the grower is required to enter the next parameters in to the controller:
A weather station is required to provide outdoor light level, temperature, humidity, wind and rain or snow conditions.