The programmable controller is a typical controller found in DDC systems. It has different types of inputs. These inputs receive signals from external devices such as sensors. The controller treats these signals according to the programmed logic, then sends signals to the appropriate devices connected to the controller outputs. It has six universal inputs, two binary inputs, two analog outputs, three binary outputs, and four configurable outputs. The logic of the controller determines how the inputs and outputs are used. A sensor/actuator bus (SA bus) and a field controller bus (FC bus) are also available on the controller.