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HART Communication Resources

HART is the digital communication standard that rides on the 4 to 20 mA loop and connects technicians to smart field instruments. These guides cover how HART works and how to put it to work, from the protocol basics to communicators, calibration, HART-IP, and wireless. They are maintained by PragOptics, the maker of OmniBus, a universal HART communicator and calibration recorder.

New to HART? Start with What is HART? for the fundamentals, then jump to any topic below.

What is HART?
How HART communication works: the 4-20 mA loop, masters, device variables, commands, DD/DTM, HART-IP, and calibration.
HART communicator
What a HART communicator is, the three form factors, primary vs secondary master, and how to choose one.
HART calibration
As-Found / As-Left, trim types, tolerance and NE43, and a step-by-step calibration procedure.
HART-IP
HART over Ethernet, gateway hosts versus direct instruments, and wireless mesh.
HART vs 4-20 mA
Why HART rides on top of the analog loop instead of replacing it.
WirelessHART
The IEC 62591 mesh, gateways, adapters, and how it relates to wired HART and HART-IP.
HART commands
Universal, common-practice, and device-specific commands, and why they enable universal tools.
HART glossary
Key HART terms defined, from Bell 202 FSK and PV/SV/TV/QV to As-Found / As-Left.
HART FAQ
Straight, answer-first responses to the HART questions technicians actually ask.