A building control system , comprising: a) a building controller including a building controller housing that is structured to mount to a DIN rail, the building controller including an I/O port and a plurality of ports for providing direct wired communication with one or more building control components (18a-18d) of a HVAC system, b) wherein at least one of the building control components include one or more of a fan, a blower, and an actuator and the building controller includes colour indication to provide an operational status of the building controller but does not include a dot matrix display; c) wherein the building controller is configured to provide control signals in accordance with a control algorithm to control the one or more building control components via the direct wired communication between the building controller and the one or more building control components of the HVAC system; and d) a user interface device , separate from the building controller , the user interface device including a user interface device housing structured to be mounted to the DIN rail, the user interface device further comprising a controller and an user interface that includes a display and an I/O port adapted to permit the user interface device to communicate with the building controller via the I/O port of the building controller , wherein the user interface device is configured to display on the display a plurality of menu screens that allow a user to locally interact with the building controller, the user interface device is configured to display one or more screens that display at least some information received from the building controller that cannot be displayed by the building controller and the user interface device is configured to solicit at least some information for the building controller . a) a building controller including a building controller housing that is structured to mount to a DIN rail, the building controller including an I/O port and a plurality of ports for providing direct wired communication with one or more building control components (18a-18d) of a HVAC system, b) wherein at least one of the building control components include one or more of a fan, a blower, and an actuator and the building controller includes colour indication to provide an operational status of the building controller but does not include a dot matrix display; c) wherein the building controller is configured to provide control signals in accordance with a control algorithm to control the one or more building control components via the direct wired communication between the building controller and the one or more building control components of the HVAC system; and d) a user interface device , separate from the building controller , the user interface device including a user interface device housing structured to be mounted to the DIN rail, the user interface device further comprising a controller and an user interface that includes a display and an I/O port adapted to permit the user interface device to communicate with the building controller via the I/O port of the building controller , wherein the user interface device is configured to display on the display a plurality of menu screens that allow a user to locally interact with the building controller, the user interface device is configured to display one or more screens that display at least some information received from the building controller that cannot be displayed by the building controller and the user interface device is configured to solicit at least some information for the building controller . <EOS>