The document provides an overview of the HART communication protocol, which enhances data transmission between smart field devices in industrial automation. It outlines the benefits of HART technology, including bi-directional communication, operational optimization, and improved diagnostics, while explaining its functionality and applications. HART-enabled transmitters, particularly pressure transmitters from brands like Rosemount and Foxboro, are highlighted as ideal solutions for pressure measurement in various process industries.

1. Everything You Need to
Know About HART
Communication Protocol
By The Transmitter Shop Inc.

2. Overview of HART Communication Protocol
• In Industrial Automation systems various types of Smart Field Devices are used.
These smart devices help in monitoring every device installed in the factory. These
devices also enable transmission of data between connected devices, both inside and
outside of the factory. This data is used to streamline factory automation and process
control.
• The data communication was accomplished through 4-20 mA loop transmitters. The
only drawback of this system is that it can only monitor one process variable at any
time.
• This is where HART-enabled smart devices such as HART transmitters can make a
difference. Today, HART protocol has become an industry standard for industrial
automation.

3. What is HART Technology?
• HART or Highway Addressable Remote Transducer was first introduced in
1980s.
• The HART Protocol facilitates digital data or signal transfer over analog
wiring systems.
• More than 300 million devices across the world are powered by HART
protocol
• HART protocol has become an industry standard for establishing
communication between host systems and smart field devices.
• the HART technology is a bi-directional communication protocol.

4. Working Principle of HART Communication
Protocol
• HART Technology is built on 202 Standards and works on frequent shift
keying (FSK) principle.
• It is made of 2 Frequencies – 12oo Hz and 2200 Hz
• The 1,200 Hz signal represents bit 1 and the 2,200 Hz signal represents bit 0.
• The HART protocol supports two communication channels at a time –4-20
mA analog signal and digital signals. The digital signals can be any
information such as the operational status of the device, diagnostics, any
measured value, and so on.

5. Modes of HART Communication Protocol
• Point-to-Point – In this type of configuration, the traditional signal is used to
define one variable, while the other important process variables are
communicated through digital signals over HART Protocol.
• Multidrop – In this type only one slave device is used to broadcast a HART
reply message. It uses only a pair of wires.

6. Benefits of Using HART Protocol for Industrial
Automation
• Optimizes operational capabilities of device data
• It identifies the potential problems before they occur and minimizes the
downtime due to equipment failure.
• Reduces device maintenance and inventory costs.
• Reduces wait times problem identification and resolution.
• Improves Safety Integrity Levels through advanced diagnostics.
• Automates record keeping.

7. Conclusion
• Due to its increasing popularity, the protocol has been updated several times
since the introduction.
• HART-enabled transmitters, especially HART pressure transmitters are
widely used in various process industries for pressure measurement. The
pressure transmitters are configured to HART communicator for achieving
desired performance.
• Rosemount and Foxboro are two prominent brands offering HART pressure
transmitters.

8. Get in Touch with us
• Address: 2531 Preston, Pasadena, TX 77503
• Toll Free: +1-888-964-8837
• Local: 281-487-3115
• Fax: 281-487-3478
• Email: sales@transmittershop.com
• Website: https://www.transmittershop.com/