Digital controls can provide control strategies and energy conserving features not possible with any other control system type. They can collect and compare information on equipment operation from a large number of inputs. The collected information is used by the system to perform complex calculations which determine control command outputs for optimal operation.
There are two general sensor types: digital and analog. Analog means varying. A varying temperature or changing pressure may be sensed by a control which in turn creates a variable voltage or amperage signal which is used as an input to the controller. Analog inputs are usually indicated by the letters AI. Analog inputs can include: