What is HART Protocol?

HARTCommunicationProtocol4-20mAInstrumentation

HART (Highway Addressable Remote Transducer)

HART is a hybrid communication protocol widely used in the process industry.

How it Works

It superimposes a digital signal on top of the standard 4-20 mA analog current loop.

  • Analog: The 4-20 mA signal carries the primary process variable (e.g., Temperature) in real-time.
  • Digital: The digital signal (FSK) carries additional data like device status, diagnostics, and configuration parameters without interfering with the analog signal.

Advantages

It allows technicians to configure "smart" instruments remotely using a handheld communicator, while still compatible with legacy analog control systems.