5. SCADAstands Supervisory Control and Data Acquisition. As the
name indicates, it is not a full control system, but rather focuses on the
supervisory level. It is a computer system for gathering and analyzing
real time data.
SCADA systems can be relatively simple, such as one that
monitors environmental conditions of a small office building, or
incredibly complex, such as a system that monitors all the activity in
a nuclear power plant or the activity of a municipal water system.
SCADA systems are used to monitor and control a plant or equipment
in industries such as telecommunications, water and waste control,
energy, oil and gas refining and transportation. A SCADA system gathers
information, such as where a leak on a pipeline has occurred, transfers
the information back to a central site, alerting the home station that the
leak has occurred, carrying out necessary analysis and control, such as
determining if the leak is critical, and displaying the information in a
logical and organized fashion.
6. Where and why, use of SCADA?
Application area :
Industrial processes : chemical, power generation and
distribution, metallurgy, …
: reactors, nuclear waste, ...Nuclear processes
Experimental physics : HEP laboratories
Application size:
20 k I/O to 450 K I/O,
1 M I/O under development
10. Communication
Internal Communication
Access to Devices
Interfacing
H/W
Multiple communication protocols supported in a single system
Support for major PLCs/DCSs but not VME
S/W
API
ODBC, DDE and OLE I/F to PC Products
OPC Client and OPC Server
ActiveX Containers
Scalability
Database
Configuration DB, alarm DB, Archive DB, log DB and
RTDB resides in the memory of the servers
SOFTWARE ARCHITECTURE
12. 1)Data acquisition
2)Alarms and event monitoring
3)Database and data login
4)Operator interface
5)Non real time control
6)Logging
7)MMI (men-machine interface) use
8)Automation, and
9)Report generation
4. MAIN FUNCTIONS
13. 5. CONTROLLING PROCESSES
I. Industrial processes include those of manufacturing,
production, power generation, fabrication, and refining, and
may run in continuous, batch, repetitive, or discrete modes.
II. Infrastructure processes may be public or private, and include
water treatment and distribution, wastewater collection and
treatment, oil and gas pipelines, electrical power transmission
and distribution, wind farms and large communication systems.
III. Facility processes occur both in public facilities and private
ones, including buildings, airports, ships, and space stations.
They monitor and control HVAC, access, and energy
consumption.
14. 6. COMPONENTS OF SCADA
1) HMI (Human Machine Interface): It is an apparatus that is
operated by human to monitor and control various processes.
2) PLC (Programmable Logic Controller): This controller is used
because they are very flexible, and economical than Remote
Terminal Units
3) Supervisory System: It collects process data and sends control
commands to the process.
4) RTU (Remote Terminal Units): This process is connected with
sensors to convert sensor signals into digital and sends digital
data to Supervisory System
5) Communication Infrastructure: It is connecting Supervisory
System to RLU’s
15. 7. SCADA ARCHITECTURE
oSCADA systems have evolved in parallel with the growth and sophistication of
modern computing technology. The following sections will provide a
description of the following three generations of SCADA systems:
1. First Generation: Monolithic
2. Second Generation: Distributed
3. Third Generation: Networked
1. First generation: Monolithic System; when SCADA systems
were first developed, the concept of computing in general centered on
“mainframe” systems. Networks were generally non-existent, and each
centralized system stood alone. As a result, SCADA systems were standalone
systems with virtually no connectivity to other systems. Wide Area Networks
were later designed by RTU vendors to communicate with the RTU. The
communication protocols used were often proprietary at that time. The first-
generation SCADA system was redundant since a back-up mainframe system
was connected at the bus level and was used in the event of failure of the
primary mainframe.
17. 2. Second generation: Distributed; the next generation of SCADA systems took
advantage of developments and improvement in system miniaturization and Local
Area Networking (LAN) technology to distribute the processing across multiple
systems. Multiple stations, each with a specific function, were connected to a LAN
and shared information with each other in real-time. These stations were typically
of the mini-computer class, smaller and less expensive than their first generation
processors.
Model of Distributed System:
18. 3. Third generation: Networked; The current generation of SCADA master station
architecture is closely related to that of the second generation, with the primary
difference being that of an open system architecture rather than a vendor
controlled, proprietary environment. There are still multiple networked systems,
sharing master station functions. There are still RTUs utilizing protocols that are
vendor-proprietary. The major improvement in the third generation is that of
opening the system architecture, utilizing open standards and protocols and
making it possible to distribute SCADA functionality across a WAN and not just a
LAN.
Model of Networked System:
19. 8. SECURITY ISSUES
The following are TSI’s (The Security Institute, a United Kingdom based professional body for security
professionals) recommendations to address some lingering security issues for SCADA:
1. Security of network communications: Implementation of strong encryption over the SCADA
network communications, to ensure that both monitored data and control commands are
encrypted.
2.Turning on security: Implementation of security features with devices on the network, especially
authentication. Using secure protocols whenever possible.
3. Knowing your SCADA network: Identifying all connections to external networks including wire-less
networks, corporate LANs and WANs, and the Internet. Also, securing the network by eliminating
all unnecessary connections to external networks.
1. Hardening of the SCADA environment: Removing all unnecessary services from the hosts on the
network. Also, just as in the corporate network environment, ensuring that all systems are
patched and up to date.
2. Conducting regular security audits: Ensuring that security practices and procedures, such as
incident response, are defined and implemented. Penetration testing of the network
environment should also be prudently conducted with inspection for potential back doors into
the SCADA network.
3. Implementing real-time threat protection: With the increasing number and complexity of attacks,
it's insufficient to simply patch the systems or maintain access/service control. One alternative is
to implement real-time threat protection in the form of network intrusion-prevention systems.
Unlike standard packet-filter firewalls, these systems perform application-layer inspection to
identify attacks that are carried in the payload and block the offending traffic in real time
20. The large territories and huge volumes of data SCADA can
handle form a formidable combination. Today’s SCADA systems
can manage anything from a few thousands to one million of
input/output channels.
The technology is still evolving in terms of sophistication as
well. SCADA systems as they are now can perform a large
variety of tasks and some systems have artificial intelligence
built into them. They are also more network-enabled, thus
paving the way for voice-data-control data convergence. With
proper planning and a custom-made installation, a SCADA
system becomes a valuable asset.
9. FUTURE OF SCADA