an introduction to fieldbus”saba.kntu.ac.ir/eecd/taghirad/theses/fieldbus.pdf · • dcs and plc...
TRANSCRIPT
1
An Introduction To“FIELDBUS”
2
• Control
What Should The Control System Do?
• Historian• Monitoring
3
• FCS (Field Control Systems)
• DDC (Direct Digital Control)
• DCS and PLC (Distributed Control Systems)
• Pneumatics
Evolution Of Control System Architecture
4
• The Need Of More Decentralization
• The Unique Needs Of Process
• Bus Power• Intrinsic Safety• The Ability To Communicate Long Distances
• Lack Of Interoperability
DCS & PLC Disadvantages
5
• Digital• Bidirectional (Half Duplex)
• Serial
• Multidrop
• Open (DD)• Interconnectivity
• Interchangeability• Interoperability
FIELDBUS
6
FIELDBUS Architecture• Host Level
• Linking Devices
• Field Level• Sensors• Actuators
• Linker (Coupler)• Bridge
• Controller• Engineering Tools
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FIELDBUS Capabilities• Host Level
• Linking Devices
• Field Level• Intelligence• Redundancy
• Asset Management
• Redundancy• Advanced Control
• Redundancy
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Solutions
• Intelligent Devices HART
• IEC& ISA
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Speed FactorReliabilityDistance Factor
Other Groups
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Fisher-Rosemount & EMERSONABB
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Terminology
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Topologies
• Bus With Spurs
• Daisy-Chain
• Tree (Star)
• Combination Off All
13
Cable Type Max. LengthA: Twisted-pair with Shield
1900 mB: Multi-twisted-pair with Shield
1200 mC: Twisted-pair without Shield
400 mD: Multi-core without Shield
200 m
Cable type versus segment length
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• Network
CONFIGURATION
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• Network
• Device
CONFIGURATION
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• Network
• Device
• Control Strategy
CONFIGURATION
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1- Identification 2- Modeling3- Control Scenario4- Planning5- Installation 6- Commissioning 7- Operation
ENGINEERING & DESIGN
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1- Choosing a Bus Standard
2- Selecting Devices
3- Designing Segments
4- Wiring (Topology)
5- Configuration
6- Documentation
PLANNING
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FOUNDATION FIELDBUS Protocol
HART Protocol
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• How It Works?Master / Slave
• Device Type: Master
Slave Burst Mode Slave
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• Topology Point-to-Point Multidrop
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• HART Layers
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• Physical Layer (Bell 202)
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• HART Protocol Rules
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• HART Commands
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FOUNDATIONTM Fieldbus H1 Technology Introduction
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The H1 FOUNDATION™ Fieldbus Model
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What Does FOUNDATION™ Fieldbus Do?
Fieldbus wire
Moves data from
here to there
Controls, alarms
Ensures secure
communication
Connects to the
wires here
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H1 Physical Layer : IEC 61158-2
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H1 Communication StackData Link Layer
• Device Type• Scheduled Communication
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H1 Communication StackData Link Layer
• Unscheduled Communication
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H1 Communication StackData Link Layer
• Unscheduled Communication
• LAS (Link Active Scheduler)
• CD (Compel Data) Schedule
• Token Passing• Data Link Time Synchronization• Live List Maintenance
• LAS Redundancy
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H1 Communication StackFieldbus Access Sublayer (FAS)
• VCR Type (Virtual Communication Relationship)
• Client / Server VCR Type
• Report Distribution VCR Type
• Publisher / Subscriber VCR Type
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H1 Communication StackFieldbus Access Sublayer (FAS)
• VCR Type (Virtual Communication Relationship)
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H1 Communication StackFieldbus Message Specification (FMS)
• VFD (Virtual Field Device)
• Communication Service
• Message Format
• Protocol Behavior
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H1 Communication StackFieldbus Message Specification (FMS)
• VFD (Virtual Field Device)
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H1 User Application
• Resource Block
• Transducer Block
• Function Block
• Device Descriptions
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H1 User Application
• Device Descriptions (DD)
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H1 System Management
• Function Block Scheduling
• Device Address Assigning
• Application Clock Distribution
• Find Tag Service
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Foundation Fieldbus H1Architecture
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• Interoperability• Greater System Functionality
• Simplicity• Accuracy
• Decentralized Function• Asset Management• Multiple Variable I/O
• Diagnostics
Fieldbus Benefits
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• Discrete I/O and Control
• Cable breaks
• Controlling Device Fails
Fieldbus Doubts