HART Communication basics

1. MIET
GONDIA
Department of electronics & comm.
HART Communication
Guided by:-
Prof. Shekhar Patle
Submitted by:-
Punam Tembhare

2.  Introduction
 What is HART?
 How HART Works?
 Features of HART technology .
 HART Communication Protocol
 HART technology can help in:
 Two Communication Channels.
 Benefits of Using HART .
 Application
 References

3.  HART® Field Communications Protocol is widely recognized
as the industry standard for digitally enhanced 4-20 mA smart
instrument communication. Use of the technology is growing
rapidly, and today virtually all major global instrumentation
suppliers offer products with HART communication.
 The HART Communication Protocol (HART = Highway
Addressable Remote Transducer) defines a bi-directional field
communication protocol standard for instrument, control and
automation systems. Actually, it's not just a standard, but the
global standard for sending and receiving digital information
across analog wires between smart devices and host systems.
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.

4.  HART (“Highway Addressable Remote Transducer”) is a
communication protocol designed for industrial process
measurement and control application.
 It is called a hybrid protocol because it combine digital and
analog communication
 The digital signal does not affect the analog reading.

5.  “HART” is an acronym for Highway Addressable Remote Transducer. The
HART Protocol makes use of the Bell 202 Frequency Shift Keying (FSK)
standard to superimpose digital communication signals at a low level on top
of the 4-20mA.
 The HART protocol communicates at 1200 bits per second without
interrupting the 4-20 mA signal and allows a host application to get two
or more physical updates per second from a smart field device.
 This is the diagram of frequency shift keying[FSK].

6.  Compatibility with standard 4-20mA wiring
 Simultaneous transmission of digital data
 Simplicity through intuitive menu-driven interfaces
 Risk reduction through a highly accurate and robust
protocol
 Ease of implementation for maximum “up-front”
cost effectiveness
 Broad product selection, with compatible devices
and software applications from most process
automation providers
 Platform independence for full interoperability in
multi-vendor environments

7.  The HART (Highway Addressable Remote Transducer) protocol is a
widely accepted standard for digitally enhanced communication with
instrumentation within the process industries
 Due to this we can convert
our PC or mobile into
HART communication.

8. THE BENEFITS OF HART PROTOCOL COMMUNICATION IN
SMART INSTRUMENTATION SYSTEMS
• Access to all instrument parameters & diagnostics.
• Supports multivariable instruments.
• On-line device status.
Digital
Capability
• Simultaneous analog & digital communication.
• Compatible with existing 4-20 mA equipment & wiring
Interoperability.
• Fully open de facto standard.
• Enhanced by Device Description Language.
Analog
Compatibility
• Field proven technology with more than 1,400,000
installations
• Large and growing selection of products
• Used by more smart instruments than any other in the
industry
Availability

9. Leverage the capabilities of a full set of
intelligent device data for operational
improvements.
Gain early warnings to variances in device,
product or process performance.
Speed the troubleshooting time between the
identification and resolution of problems.
Continuously validate the integrity of loops
and control/automation system strategies.
Increase asset productivity and system
availability.

11. • Detect device and/or process connection problems real time.
• Minimize the impact of deviations by gaining new, early warnings.
• Avoid the high cost of unscheduled shutdowns or process disruptions
Increase Plant Availability
• Quickly verify and validate control loop and device configuration.
• Use remote diagnostics to reduce unnecessary field checks.
• Capture performance trend data for predictive maintenance
diagnostics.
• Reduce spares inventory and device management costs.
Reduce Maintenance Costs
• Enable automated record keeping of compliance data.
• Facilitates automated safety shutdown testing.
• Raise SIL/safety integrity level with advanced diagnostics.
• Take advantage of intelligent multivariable devices for more thorough,
accurate reporting.
Improve regulatory compliance

12. Cost-Saving Applications.
Inventory Management Applications.
Open Architecture Applications.
Safety integrity.

14. • It is based on the Bell 202 standard, using frequency shift keying (FSK) to
communicate at 1200 bps
HART Physical Layer
• It defines a master-slave protocol - in normal use, a field device only replies
when it is spoken to.
HART Data Link Layer
• It provides routing, end-to-end security, and transport services.
Network Layer
• The Data-Link Layer ensures communications are successfully propagated
from one device to another.
Transport Layer
• It defines the commands, responses, data types and status reporting supported
by the Protocol.
Application Layer

15. • provide functions which must be implemented in all field
devices
Universal Commands
• - provide functions common to many, but not all field devices
Common Practice Commands
• - provide functions that are unique to a particular field device
and are specified by the device manufacturer
Device Specific Commands
• provide a set of standardized functions for instruments with
particular measurement types, allowing full generic access
without using device-specific commands.
Device Family Commands

16. • Read manufacturer and device type.
• Read or write 32-character message.
• Read primary variable (PV) and units.
• Read or write final assembly number .
Universal
Commands
• Read selection of up to four dynamic variables.
• Write damping time constant.
• Write device range values
• Write transfer function (square root/linear).
• Read or write dynamic variable assignments
Common
Practice
Commands
• Read or write low-flow cut-off.
• Read or write density calibration factor.
• Read or write materials or construction information.
• Trim sensor calibration.
• Local display information.
Device
Specific
Commands

18.  www.google.com
 www.ask.com
 http://wiki.answers.com
 http://www.ehow.com
 https://www.google.co.in/search
 www.wikipedia.in

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