HART Protocol

The majority of smart field devices installed worldwide today are HART-enabled. But some new in the automation field may need a refresher on this powerful technology.

Simply put, the HART (Highway Addressable Remote Transducer) Protocol is the global standard for sending and receiving digital information across analog wires between smart devices and control or monitoring system or Handheld communicators.

More specifically, HART is a bi-directional communication protocol that provides data access between intelligent field instruments and host systems (DCS/PLC or Handheld Communicator). A host can be any software application from technician’s hand-held device or laptop to a plant’s process control, asset management, safety or other system using any control platform.

HART Technology

HART technology is easy to use and very reliable when used for commissioning and calibration of smart devices as well as for continuous online diagnostics.

There are several reasons to have a host communicate with smart devices. These include:

• Device Configuration or re-configuration
• Device Diagnostics
• Device Troubleshooting
• Reading the additional measurement values provided by the device
• Device Health and Status
• Much more

Years of success using these benefits explain why HART technology is the largest of all communication protocols, installed in more than 30 million devices worldwide.

If you’ve ever used a land-line telephone and noticed the Caller ID display to take note of who is calling, you already know half of what the HART Protocol does—it tells “who” is calling. In an industrial automation network “who” is a microprocessor-based smart field device. In addition to letting such smart field devices “phone home,” HART Communication lets a host system send data to the smart instrument.

HART emerged in the late1980s based on the same technology that brought Caller ID to analog telephony. It has undergone continued development, up to and including automation products now shipping with built-in WirelessHART Communication.