HART

HART (Highway Addressable Remote Transducer) is an open industrial communication protocol maintained by the FieldComm Group that allows digital diagnostic and configuration data to be superimposed on a standard 4–20 mA analog signal, enabling two-way communication with field instruments over existing wiring. Products carrying this tag include Allen-Bradley analog input and output modules across several I/O platforms — among them the 1719 series (Zone 2/Class I, Div 2 rated), 1718 series (Zone 1 rated), Flex 5000 (5094), Point 5000 (5034), and Compact 5000 (5069) families — as well as HART loop converters and intrinsic safety converters such as the 937CU and 931S series. Channel counts typically range from 4 to 8 per module, with isolated variants available.