What is HART Communication Protocol? – Architecture | New Topic

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Author Name: Arun Paul.

What is HART Communication Protocol?

The HART (Highway Addressable Remote Transducer) communication protocol is a hybrid analog/digital communication protocol commonly used in industrial automation and process control systems. It enables digital communication using classic 4-20 mA analog wiring, making it compatible with older systems while also introducing new features.

HART Communication Protocol Specifications

• It sends digital signals superimposed on the usual 4-20 mA analog signal.
• HART allows you to read and write configurations to field equipment such as transmitters, valves, and sensors.
• It’s “Multidrop mode” allows you to connect up to 15 devices to a single pair of wires.
• It provides access to device diagnostics, calibration data, and settings without disrupting operations.
• Many instrument manufacturers provide widespread support.

Architecture or Block Diagram of HART Communication Protocol

Explanation of the above Block Diagram –

• Control System (PLC, DCS, or Host PC): This system handles process control and communicates with field devices.
• HART Modem or Interface: Converts digital data to FSK (Frequency Shift Keying), and vice versa. It could be built into the host or external.
• Field Instrument (Transmitter/Actuator): A smart device that can provide both analog signals (pressure, temperature) and digital data (device status, diagnostics).
• Sensor/Transducer: Measures the real physical parameter and transfers it to the field instrument.

Application of HART Communication Protocol

Here we have listed some HART Communication Protocol Applications –

• Field Device Configuration & Calibration
• Device Diagnostics & Troubleshooting
• Multivariable Communication
• Asset Management Systems (AMS)
• Remote Monitoring & Control