This document provides an overview of embedded systems used in modern power industries, including distributed control systems (DCS), supervisory control and data acquisition (SCADA) systems, and various communication protocols. DCS are the main automation systems that provide control and infrastructure for power plants. SCADA systems are used for larger, more complex electrical systems and cover large geographical areas. Common communication protocols discussed are DNP3, ProfiBUS, and WirelessHART, with details on their architecture, implementation, and use cases.

1. Survey: Embedded Systems
In Modern Power Industry

2. CONTENTS
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DCS (Distributed Control Systems)
Distributed Control Systems
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SCADA Systems
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Communication Protocols
–
DNP3
–
ProfiBUS
–
WirelessHART
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3. DCS (Distributed Control Systems)
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Automation system for an independent Unit
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Main Brain of the Power Plant
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Provide Infrastructure for implementing the control
system algorithms.
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Complex Electronic system
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Centre point of all Analog and Digital Signals
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Major Market Players: ABB, Siemens, ALSTOM,
Metso, GE
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4. DCS (Distributed Control Systems)
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Layer 0: Embedded
Processor
ASIC /FPGA / DSP
Processors /SoC
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FPGA: Reconfigurable
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MIMO Design: 2k – 10k I/O
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Redundancy: An Important
concept of systems
engineering.
Vetical layers DCS
Source: Metso Automation: MaxDNA Systems
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5. DCS (Distributed Control Systems)
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Can be implemented as System-on-a-Chip (SoC)
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Hardware/ Software Partitioning:
–
Intellectual Property Re-use
–
Cost optimization
–
Maximize performance
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6. DCS (Distributed Control Systems)
DCS Architecture
Typical DCS Architecture for coal fired power plant Source: ALSTOM Alspa 6
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7. CONTENTS
●
Distributed Control Systems (DCS)
●
SCADA Systems
●
Communication Protocols
–
DNP3
–
ProfiBUS
–
WirelessHART
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8. SCADA Systems
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SCADA – Supervisory Control & Data Acquisition
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Used for very large complex electrical systems
–
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Smart Grids
One system covers large no of substations, control stations,
swicthyards, load dispatch centres
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Data collection from different units, processing and logging
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System Security from cyber attacks
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I/O size: 20k to 450k I/O ports
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9. SCADA Systems
SCADA Architecture
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Typical architecture of SCADA System (Source: Juniper Networks)
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10. SCADA Systems
Key components:
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I/O hardware – Remote Terminal Units (RTUs)
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Network backbone
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Human Machine Interface (HMI)
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Control and processing Systems
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Database management
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Security Software
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11. SCADA vs DCS
SCADA
DCS
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I/O ports: 20k - 450k
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I/O ports: 2k -15k
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Event and Data
acquisition oriented
–
Process Oriented
–
Systems like power
plants, which function as
an independent unit
–
Systems spread over a
large geographical area
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12. CONTENTS
●
Distributed Control Systems (DCS)
●
SCADA Systems
●
Communication Protocols
–
DNP3
–
ProfiBUS
–
WirelessHART
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13. DNP3 (Distributed Network Protocol)
–
Communication protocol used in Power industry for data
communication
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Non proprietary protocol
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Managed by DNP3 users group
–
Extensively used in SCADA systems,communication between
Master control centre and RTUs
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14. DNP3 (Distributed Network Protocol)
DNP3 Architecture
DNP3 user software
S/W
Application Layer
Data Link layer
H/W
Physical Layer
Network >>
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15. DNP3 (Distributed Network Protocol)
ADDR. ADDR.
LEN
CTRL
START
LSB
MSB
DEST.
LSB
MSB
SOURCE.
LSB
MSB
CRC
Frame Format for DNP3
DIR
PRM
FCB
FCV
(DFC)
FUNCTION CODE
Control Byte
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16. DNP3 (Distributed Network Protocol)
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Protocol Implementation in RTUs
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Implementation as FPGAs over ethernet/ RS232C
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Protocol Performance with network traffic
Performance Analysis of DNP3
in a heterogeneous traffic environment [1]
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17. CONTENTS
●
Distributed Control Systems (DCS)
●
SCADA Systems
●
Communication Protocols
–
DNP3
–
ProfiBUS
–
WirelessHART
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18. ProfiBUS Protocol
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Acronym for Pro(cess)fi(field) bus
Communication protocol used in Power industry for data
communication
Proprietary protocol
Developed by Siemens and BMBF (German Dept of Education and
Research)
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Extensively used in SCADA as well as DCS Systems
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Architecture based on OSI Model (Open Systems architecture)
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19. ProfiBUS Protocol
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2 types
–
–
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ProfiBUS DP (Decentralised Peripherals)
ProfiBUS PA (Process Automation)
Physical layer may be RS485 and Optical Fibre network
network topology change with DP/ PA/ coupled networks and type of
physical layer
–
Different bandwidth
–
Change in no of devices per network
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20. ProfiBUS Protocol
ProfiBUS Architecture
User Interface
Direct Data link Mapper
---
OSI layers
not used
by ProfiBUS
-FDL
Physical Layer
Network >>
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21. CONTENTS
●
Distributed Control Systems (DCS)
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SCADA Systems
●
Communication Protocols
–
DNP3
–
ProfiBUS
–
WirelessHART
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22. WirelessHART Protocol
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Standard wireless protocol used in process automation industry
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Used in Wireless Instrumentation
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Major Advantages
–
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Easy Maintenance
–
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Savings in Material (Network/Copper cable)
Reliability
Risks
–
Data Security/ Protection from cyber attacks
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23. WirelessHART Protocol
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4 Layer Abstraction
–
Gateway
–
Network Manager
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Field Devices
–
Security manager
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24. WirelessHART Protocol
WirelessHART Architecture
WirelessHART architecture. Certain Layers
of OSI architecture are missing.Source: [2]
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25. WirelessHART Protocol
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Mesh topology in a power plant using WirelessHART
Communication of RTUs with control centre via gateways. Source [2]
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26. WirelessHART Protocol
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Honeywell XYR6000 series Instruments based on
WirelessHART technology
Pressure
Transmitters
Position
Transmitters
Temperature
Transmitters
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27. References
[1] Alcides Ortega,Christiane Marie Schweitzer, “Performance Analysis of Smart Grid
Communication Protocol DNP3 over TCP/IP in a Heterogeneous Traffic Environment ” - Ilha
Soltiera Brazil
[2] Jianping Song et al., “WirelessHART: Applying Wireless Technology in Real-Time
Industrial Process Control”, IEEE Real-Time and Embedded Technology and Applications
Symposium.
Image sources taken from various product manufacturers mentioned along with the
image.
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28. THANK YOU
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