An arrangement (100, 600) for use in a building automation system BAS, comprising: a memory (160, 660) storing programming instructions, a plurality of data values (124, 624 2) including data values corresponding to each of a first object data record (432a, 432g) having a first format and second object data record having a second format different from the first format, wherein the first object data record corresponds to a first BAS device (102a, 602), and the second object data record corresponds to a second BAS device (102b, 602); a function library including a plurality of function definitions for BAS devices, each function (128 x) defining a predetermined set of output values for a corresponding BAS device type; a set of function mappers including a plurality of software functions to convert data accessed via the object data records (432 x) into a format of data for a corresponding function (128 x); a display (156, 656); a user input device (158, 658); a processing circuit (152, 652) operably coupled to the memory (160, 660) and the display (156, 656), the processing circuit (152, 652) configured, when executing the programming instructions, to receive additional data values from one or more BAS devices (102a, 102b, 102n, 602, 604, 606) via a network; store the additional data values in the memory (124, 160, 624 2, 660); request within a software operation data pertaining to the first object data record; retrieve, from the function library, a stored function (128 1) appropriate for the first object data record, said function (128 1) defining a third, uniform data interface format; retrieve at least one data value corresponding to the first object data record from the memory (160, 660); identify a particular function mapper within the set of function mappers associated with the first object data record; map, by the identified function mapper, the at least one data value corresponding to the first object data record to the third format; provide the requested data based on the mapped at least one data value to the software operation via the function; execute the software operation to generate at least a portion of a display graphic on the display (156, 656), the appearance of the portion of the display graphic corresponding at least in part to the mapped at least one data value. a memory (160, 660) storing programming instructions, a plurality of data values (124, 624 2) including data values corresponding to each of a first object data record (432a, 432g) having a first format and second object data record having a second format different from the first format, wherein the first object data record corresponds to a first BAS device (102a, 602), and the second object data record corresponds to a second BAS device (102b, 602); a function library including a plurality of function definitions for BAS devices, each function (128 x) defining a predetermined set of output values for a corresponding BAS device type; a set of function mappers including a plurality of software functions to convert data accessed via the object data records (432 x) into a format of data for a corresponding function (128 x); a display (156, 656); a user input device (158, 658); a processing circuit (152, 652) operably coupled to the memory (160, 660) and the display (156, 656), the processing circuit (152, 652) configured, when executing the programming instructions, to receive additional data values from one or more BAS devices (102a, 102b, 102n, 602, 604, 606) via a network; store the additional data values in the memory (124, 160, 624 2, 660); request within a software operation data pertaining to the first object data record; retrieve, from the function library, a stored function (128 1) appropriate for the first object data record, said function (128 1) defining a third, uniform data interface format; retrieve at least one data value corresponding to the first object data record from the memory (160, 660); identify a particular function mapper within the set of function mappers associated with the first object data record; map, by the identified function mapper, the at least one data value corresponding to the first object data record to the third format; provide the requested data based on the mapped at least one data value to the software operation via the function; execute the software operation to generate at least a portion of a display graphic on the display (156, 656), the appearance of the portion of the display graphic corresponding at least in part to the mapped at least one data value.