Answer
HART = Highway Addressable Remote Transducer.
HART Protocol : It is a bidirectional digital communication protocol used between intelligent field instruments and host/control systems.
Basic principle
Traditional instrumentation commonly uses a 4−20mA analogue current loop.
HART allows digital information to be superimposed on the conventional 4–20 mA signal.
Therefore, the same pair of wires can carry:
4–20 mA analogue signal
+
digital communication
- Remote configuration of transmitters
- Calibration and zero/span adjustment
- Device diagnostics and fault detection
- Reading additional process variables
- Checking instrument health/status
- Identifying device tag, serial number and range
- Troubleshooting without removing the instrument
- Communicating with smart transmitters through a HART communicator