Brief idea about HART (Highway Addressable Remote Transducer

HART is a communication protocol used for industrial process measurement and control applications. HART is a hybrid protocol. Analog + Digital communication. HART Analog Communications -use industry standard 4-20 mA signal only –only one parameter (Process Variable or Controller Output) –communicated to the host system. HART Digital Communications –Added information (Device Status and Diagnostic Alerts;Process Variables and Units;Loop Current and % Range, Basic Configuration Parameters, Manufacturer and Device Tag etc.,) – 35- 40 information items. HART Digital Communications – Low level modulation superimposed on the standard 4-20 mA current loop –BELL 202 MODEM- Frequency Shift Keying (FSK) – Logic 1 – 1200 Hz and Logic 0 –2200 Hz (with an amplitude of –0.5mA to +0.5mA) – Device configuration, non-real-time diagnostics, and status monitoring. Two-way communication Master/Slave Protocol (Message Rate –2) HART burst mode communications (Message Rate- 3) Multivariable Instruments. HART Multidrop Mode. Interoperability . Benefits of HART Communication Improved Plant operation Commissioning and Installation Plant operation and improved quality Maintenance Operational Flexibility Instrument Investment Protection Digital Communication Control in Field Devices Hand-Held Communicator