Improvements in building management systems

A Building Management System (BMS) controller 100, receives an input 106 which is detected by an input circuit 102 to determine the input type. The BMS controller 100 operates according to an appropriate input mode suitable for the detected type of input 106. The input types may number three or more including those of analogue voltage, analogue current, resistance and a digital signal. The BMS controller may operate according to configurations chosen to be suitable to the detected input 106 type. The configuration may be the same as the input circuit 102 configuration used during the input 106 type detection. The BMS controller may have a memory 112 for saving or retrieving the detected input 106 type. The input circuit 102 may operate periodically to detect the type of input 106, and detect whether a different input 106 type has been connected. Determination of input 106 type may be performed by comparing an input 106 voltage against a threshold or by measuring input 106 impedance, changing the input impedance and re-measuring it. Input 106 type may also be determined by making two time separated measurements under the same conditions.