In smaller greenhouses, a Rack Drive For Greenhouse manual system opened and closed yourself could be installed. These work easiest when the screen material is backed by a monitor system.
Start time – when each morning will the display system start operation
Stop period – when in the afternoon will the display screen system stop operation
Light level – in what light intensity will the 
screen become activated either to open or close
Maximum/minimum temperature – what are the limitations of temperature desired
Maximum/minimum humidity – What are the limits of humidity desired
Gap positions – this models the percent open or close placement under different conditions such as early on a winter early morning to reduce thermal shock or through the summer to supply better shading. The gap techniques 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 lessen heat loss, the screen can be closed early below high wind speed conditions
Snow detection – this can open the display screen and turn on the heat when it begins to snow.
The standard system uses nylon monofilament or stainless steel cables to support the screen materials. The screen material can either 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 moves the industry leading of the screen materials. Control is certainly either with a manual change or electronic controller.
Based on the above, the grower must 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.