1 Wireless Communications for SCADA Systems BCWWA 2008

Wireless Data Communications

for SCADA Systems

2 Wireless Communications for SCADA Systems BCWWA 2008

Advanced SCADA Features

Networking (Communication Anywhere to Anywhere)

Data Reliability (No Communication Errors)

Data Security (Immune to Intrusion)

Communication

Network

3 Wireless Communications for SCADA Systems BCWWA 2008

“Open” Communication Solutions

Versatile IEDs

• Pressure Control

• Flow calculations

• Pumps Start

• etc.

SCADA

• Wonderware • Intellution • Factorylink • etc.

• 900 Mhz Conventional

• 900MHz S.Spectrum

• Analog Trunking

• VHF / UHF Conventional

• UHF-900 MHz MAS System

• Telco Network

• GSM/GPRS

• Satellite

• Microwave…….

Versatile

Interface

• MODBUS • DNP 3.0 • OPC • MDLC over TCP/IP • etc.

Versatile

Media

Applications

• Pressure/Flow • Maintenance • Leak detection • etc.

PLC Interface

• Allen Bradley

• Modicon

• Etc.

4 Wireless Communications for SCADA Systems BCWWA 2008

A Communication Oriented RTU 1/3

Programmable Controller

Communication Modem,

Remote

Control

Local

Control

A powerful combination of two functions:

– Programmable Logic Controller

– Communication Modem

5 Wireless Communications for SCADA Systems BCWWA 2008

A Communication Oriented RTU 2/3

Local

Control of

Remote

Sites

Reporting

By

Event

Node

Linking

two Media

Protocol

Converter

for PLC

Links

Store and

Forward

Repeater

F1-F1

Time

Synchroniz

ation

RTU

6 Wireless Communications for SCADA Systems BCWWA 2008

A Communication Oriented RTU 3/3

Local

Process

Network

Comm.

++

+++

-

+

Polling

via radio

Report

by Event

PLC

RTU

7 Wireless Communications for SCADA Systems BCWWA 2008

“Store and Forward” Links

S&F

FIU

All radio links may use the same frequency !

S&F Repeater

RTU

RTU

RTU

SCADA HMI

8 Wireless Communications for SCADA Systems BCWWA 2008

Backup Links Enhance Reliability

IP Gateway

Damaged Wire-line

Backup Radio

RF

SCADA Control Center

Line

RF

RTU

Radio

RTU

RTU

RTU RF

9 Wireless Communications for SCADA Systems BCWWA 2008

Wide Area SCADA-Data Network

ToolBox

Primary

Water SCADA

Secondary

MCC

Ethernet

Ethernet

IP

Gateway Line Based

network

S&F

Repeater

RTU and

Comm. Node

RTU for

Pumping Station

RTU for

Reservoir

IP

S&F

Repeater

10 Wireless Communications for SCADA Systems BCWWA 2008

Complex SCADA System

Main

ToolBox

Primary

MCC

Secondary

MCC

Remote Ethernet

Local Ethernet

IP Gateway Line

Based IP

RTU & Data

Comm. Node

Remote

ToolBox

Wireline Comm.

RTU & Data

Comm.

S&F

RTU & Data

Comm. Node

(SLIP)

Wireline

Comm.

RTU & Data

Comm. Node

RTU & Data

Comm. Node Prime Link

Backup

Link

Prime Link

Prime Link

Printer

Backup

Link

TS

11 Wireless Communications for SCADA Systems BCWWA 2008

Reporting in Wireless SCADA Systems

• Cyclic Polling of RTUs – Complete Polling - “Tell me about all your conditions”

• Time consuming process not suitable for wireless media

– Report by Exception – “Tell me about only what changed”

• Change of state that does not require immediate attention

– Cyclic Health Check - “Indicate shortly that you are alive”

• To minimize the health check cycle (leave time gaps for alarms)

• Initiating Unsolicited Messages – Report By Event - Predefined Alarm conditions

• Must get immediate attention of the operator (critical alarms)

• Group Calls – Burst messages – “Everyone Accept this Message”

• No acknowledgement is expected (“all keep quite for 5 minutes”)

12 Wireless Communications for SCADA Systems BCWWA 2008

Multiple Address System Network

Site 2

SCADA

Site 1

Remote Programming

F2

F1

F2

F1

Using the 7-Layer

protocol sites may

be configured for

single frequency F3

F3

F3 F3

F3

RTU RTU

RTU

RTU

F1 F2

13 Wireless Communications for SCADA Systems BCWWA 2008

Wireless IP Connection with SCADA

Master

Control

Center

Programming

ToolBox

IP

Network Ethernet

Wireless IP Infrastructure

IP

Gateway

IP Con.

IP Con.

RTU

IP Con.

IP Con.

Programming

STS

IP Con.

RTU

900 MHz – 5.7 GHz

RTU

14 Wireless Communications for SCADA Systems BCWWA 2008

Wireless GSM/GPRS Network

Site 4

Site 1

Site 2

Site 3

SCADA

Micro Wave

Back Bone

Voice Voice

Voice

RTU

RTU RTU

RTU

15 Wireless Communications for SCADA Systems BCWWA 2008

Combined PLC and I/Os with RTU

Wireless

Network

Customer Site

RTU With radio

STS

ToolBox

I/O

Control

Installed PLC or IED

I/O

Control

PLC or IED

with Native

protocol

16 Wireless Communications for SCADA Systems BCWWA 2008

SCADA Security Incident Trends

5

12 2 2 3

4

1

6

13

28

18

6

1982

- 19

93

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

Sep

t. 20

05

* Projected

20* 22*

Something Big

Changes Here

Source: Eric Byres

17 Wireless Communications for SCADA Systems BCWWA 2008

Combined Set of Solutions May Help

• Physical Security – Provide adequate security to remote sites

• Firewalls – Protecting the corporate network

• Use of private data network – Public networks are often vulnerable

• Use of “complex” protocol structure – Need for specific analyzer

• Communications Security – Combined Encryption and Authentication

– Multiple passwords across the system, etc.

IP Gateway

Master Control Center

18 Wireless Communications for SCADA Systems BCWWA 2008

Cost Saving Analysis 1/2

• Calculate the overall Economic factors:

– Cost of lost potable water due to bursts and leakages

– Cost of electric energy during designated period

– Cost for repairs and replacement of equipment

– Cost travel to remote sites for periodic checkup

– Cost of system supervision and manual data collection

Cost (without SCADA) – Cost (with SCADA)

Saving = -------------------------------------------------------------- (%) Cost (without SCADA)

19 Wireless Communications for SCADA Systems BCWWA 2008

Cost Saving Analysis 2/2

0

500

1000

1500

2000

2500

Without SCADA With SCADA

Cost of lost potable water due to

bursts and leakages

Cost of electric energy during

designated period

Cost for repairs and replacement

of equipment

Cost travel to remote sites for

periodic checkup

Cost of manual data collection

Total

20 Wireless Communications for SCADA Systems BCWWA 2008

With Simple Protocol

• Network Addressing

• Error Detection

& Message Retry

• Diagnostics

• Data Security

• Main Application

With Layered Protocol

•Built In

•Built In

•Built In

•Built In

• Main Application

System Programming Tasks