![Page 1: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/1.jpg)
Automation Committee
![Page 2: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/2.jpg)
Understanding SCADA Communication Protocols
Module: Basic Concepts
Host:James MondaleWayne Wilson
![Page 3: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/3.jpg)
Reduce background noisePlease mute your phones
![Page 4: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/4.jpg)
Gain working knowledge of communication SCADA Protocols
Learn the basics layers and architectures
Examine various architectures SCADA Protocols
Learn about common Protocol errors that can occur in your SCADA system
![Page 5: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/5.jpg)
Introduction
![Page 6: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/6.jpg)
In telecommunication,• a communication protocol is a system of rules that
allow two or more entities of a communications system to transmit information via any kind of variation of a physical quantity.
• Protocols may be implemented by hardware, software, or a combination of both.
![Page 7: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/7.jpg)
• In SCADA it includes the collecting of the information via;• RTU (remote terminal unit), • PLC's (Programmable Logic Controllers) • IED's (Intelligent electronic devices)
Transferring it back to the central site, carrying out any necessary analysis and control and then displaying that information on a number of operator screens or displays.
![Page 8: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/8.jpg)
![Page 9: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/9.jpg)
DNP3
PROTOCOLS are available for many types of SCADA systems
• Industrial Controls
✓
✓
✓✓
![Page 10: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/10.jpg)
DNP3
PROTOCOLS are available for many types of SCADA systems
✓• Process Automation
✓
✓✓
![Page 11: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/11.jpg)
DNP3
PROTOCOLS are available for many types of SCADA systems
• Power Systems
✓
✓
✓
✓
✓
![Page 12: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/12.jpg)
Protocol Layer OverviewThe Open Systems interconnection model (OSI) model is used to define how data communication occurs on computer networks.
Fiber Optic
![Page 13: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/13.jpg)
Scada systems in water & wastewater commonly useModbus or DNP3 .
Modbus and DNP3 are both byte-oriented protocols. Modbus is an application layer protocol, while DNP contains Application and Data Link Layers, with a pseudo-transport layer.
Both protocols are widely used over a variety of physical layers, including RS-232, RS- 422, RS-485, and TCP/IP.
![Page 14: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/14.jpg)
The term “Modbus” typically refers to one of three related protocols: Modbus ASCII, Modbus RTU, or Modbus TCP/IP
Multi Drop network
Message Query initiates from Master
Master can broadcast to all slaves
or a single one
![Page 15: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/15.jpg)
Multi Drop network
Slaves returns a response to only messages addressed to them individuallyBut do not respond to broadcast messages.
![Page 16: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/16.jpg)
Modbus Slaves do not initiate messages on their own
DNP3
DNP3 Slaves can report by exception
![Page 17: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/17.jpg)
![Page 18: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/18.jpg)
Difference between Modbus and DNP3 Communication Protocols
![Page 19: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/19.jpg)
Let’s use Modbus as an example to demonstrate how protocols work
![Page 20: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/20.jpg)
Physical Media
![Page 21: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/21.jpg)
Data Model
![Page 22: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/22.jpg)
Service request from master
Protocol Data Unit (PDU)
Fields in PDU are broken down into Bytes
![Page 23: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/23.jpg)
4 Basic Data types
![Page 24: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/24.jpg)
Slave Address Function
Code
Data Field
CRCError
Check
Function Code field determines read or write and in which field
![Page 25: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/25.jpg)
Slave memory registers
![Page 26: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/26.jpg)
![Page 27: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/27.jpg)
Typical problems
![Page 28: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/28.jpg)
• Hardware problems
• Mis-wired cabling
• Faulty Cable connectors
• Corrosion on connector ends
• Cables not “snapped” into socket
• Poor signals
![Page 29: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/29.jpg)
• Network collisions• Duplicate IP Addressing• Overwriting registers• Polling loop problems
• Software (protocol ) related problems
![Page 30: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/30.jpg)
Questions?
![Page 31: Automation Committee - cdn.ymaws.com › ... › automation_committee › SCADA_Protoc… · Automation Committee . Understanding SCADA Communication Protocols Module: Basic Concepts](https://reader034.vdocuments.us/reader034/viewer/2022042322/5f0c0f107e708231d4338ae2/html5/thumbnails/31.jpg)
Thank You!The End