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The Highway Addressable Remote Transducer (HART) protocol was originally developed and is currently managed by the HART Communication Foundation (HCF). Based upon Bell 202 modem technology, it first allowed digital configuration of "smart" 4-20 mA industrial field devices.

Because of the large installed base (85%) of 4-20 mA field devices, HART is one of the most popular fieldbuses today. Because the modem signals which ride on top of the 4-20 process variable signal have an average voltage of zero, HART does not affect legacy 4-20 mA signal conditioners, which means HART-compliant field devices can replace standard field devices. Handheld HART communicators can be used to configure a field device or to gather diagnostics from the device while the plant process is still running.

HART has been expanded in recent years to allow fully digital, multi-drop communications between HART masters and HART devices. Generally, the field device is supplied with a continuous 4 mA of current, and all communication is performed in a master-slave manner between the controller and the device.

All HART devices must supply a device description (DD) file which describes the device to the controller. The HART Communication Foundation maintains a compliance test suite for conformance and interoperability. Once the test suite is passed, the device is registered with the HCF and can utilize the logo and marketing resources of the HCF.

What Can AB Tech Solution Do for Your Foundation Fieldbus Product Development?
  • Obtain manufacturer and product identifiers from HART Communication Foundation
  • Develop a fully-compliant product for you
  • Add HART capability to your existing product
  • Enhance the features and functionality of your product
  • Develop the required DD (device description) files
  • Perform interoperability testing
  • Obtain HART Communication Foundation registration for your products