my scada

SCADA

By : JEORAM FLORESBSEE

Contents

Introduction of SCADAHow SCADA System Works?Components of SCADA SystemSystem Concept of SCADASCADA ArchitecturesProtocolsSecurity and Vulnerability of SCADA

System

WHAT IS SCADA

SCADA stands for Supervisory Control And Data Acquisition.

SCADA refers to a system that collects data from various sensors at a factory, plant or in other remote locations and then sends this data to a central computer which then manages and controls the data.

generally refers to an industrial control system(ICS).

It is a production automation and control system based on PCs.

What is the purpose of SCADA

The primary purpose of SCADA is:

to monitor to control Alarming functions Data presentation Data acquisition

History of SCADA System

Early 1900’s with advent of telemetry.Early 1960’s as an electronic system (I/O)

between MTU and RTU station.Early 1970’s DCS were developed.Late 1990’s Good SCADA system yet

flexible enough to adapt tomorrow’s changes.

History of SCADA System

SCADA (supervisory control and data acquisition) has been around as long as there have been control systems.

The first ‘SCADA’ systems utilized data acquisition by means of panels of meters, lights and strip chart recorders.

Figure 2.1Sensors to panel using 4–20 mA or voltage

As needs grew to monitor and control more devices in the plant, the PLCs were distributed and the systems became more intelligent and smaller in size.. Although initially RTU was often a dedicated device, PLCs are often used as RTUs these days.

As the requirement for smaller and smarter systems grew, sensors were designed with the intelligence of PLCs and DCSs. These devices are known as IEDs (intelligent electronic devices). The IEDs are connected on a fieldbus such as Profibus, DeviceNet or Foundation Fieldbus to the PC.

SCADA

Supervisory Control and Data Acquisition.SCADA system are used to monitor and

control remote or local industrial equipment facilities.

Combination of telemetry and data acquisition.

WHAT IS DATA ACQUISITION

Data acquisition refers to the method

used to access and control information or data from the equipment being controlled and monitored. The data accessed are then forwarded onto a telemetry system ready for transfer to the different sites.

SCADA is not just a hardware, neither a software. It’s a concept, it’s a system as a combination of special hardware, software and protocols.

SCADA encompasses the collecting of the information, 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. The required control actions are then conveyed back to the process

Where is SCADA Used?

Typically, SCADA systems are used to automate complex industrial processes where human control is impractical systems where there are more control factors, and more fast-moving control factors, than human beings can comfortably manage.

Application in Industries:Electric power generation, transmission and

distributionWater Management SystemsBuildings, facilities and environmentsManufacturing SystemsMass Transit Systems, Environmental Control Systems

How SCADA System Works ?

A SCADA System performs four functions:1. Data acquisition2. Networked data communication3. Data presentation4. Control

SCADA Components:

1. Sensors and Control Relays

2. Remote Telemetry Units (RTUs)

3. SCADA Master Units4. Communication Network

Sensors and Control Relays

. Sensors (either digital or analog) and control relays that directly interface with the managed system.

Remote Telemetry Unit (RTU)These are small computerized units

deployed in the field at specific sites and locations.

RTUs serve as local collection points for gathering reports from sensors and delivering commands to control relays.

Scada Master UnitsThese are larger computer consoles that

serve as the central processor for the SCADA system.

Master units provide a human interface to the system and automatically regulate the managed system in response to sensor inputs.

Communication Network

The communications network that connects the SCADA master unit to the RTUs in the field.

System Concepts of SCADA

System Concept of SCADA

SCADA

is a kind of software application program used for the process control and gather real time from remote locations for exercising this control on equipment and conditions.

Scada SystemThe RTUs and PLCs are responsible for

data collection such as meter readings, equipment status etc. and communicate back to the SCADA system. This data can be stored in a database for later analysis or monitored by a supervisor to take appropriate actions if required.

COMPOSITION

Input/output signal hardware


Network



Human Machine Interface (HMI)

SCADA


Controllers


Database (A structured set of data held in a computer, esp. one that is accessible in various ways)


Communication and software

The SCADA consist of Hardware and Software components.

The hardware collects and feed data into a computer with SCADA software installed.

The data is then processed by the computer before presenting it in a timely manner.

SCADA SYSTEM

Signal hardware (I/O)

controllers

networksUser interface (HMI)

CommunicationsEquipment and software


CONTROL/ MONITOR FUNCTION

A system or the complete site is usually spread over a long geographical distance, SCADA is the central system for control and monitor of such a site or system.


A Programmable Logic Controller (PLC) or Remote Terminal Unit automatically performs the main site control process.

The host control functions in most cases are limited to the capability of supervisory level or site override.


SCADA SUBSYSTEM

HMI-is the apparatus which presents the process data to a human operator, and through this, the human operator monitors and control the process.

a supervisory(computer) system, gathering (acquiring) data on the process and sending commands(control) to the process.


RTU-connecting to sensors on the process, converting sensor signals and sending digital data to the supervisory systems.

PLC-used as field devices because they are more economical, versatile, flexible, and configurable than special purpose RTU.

Communication infrastructure connecting the supervisory system to the RTU.

System Concept of SCADA Data Acquisition begins at the RTU or PLC

level and includes meter readings and equipment status reports that are communicated to SCADA as required.

Data is then compiled and formatted in such a way that a control room operator using the HMI can make supervisory decisions to adjust or override normal RTU (PLC) controls.

Remote Terminal Unit (RTU)

What is RTU?

Remote Terminal Unit

What is RTU?

An RTU monitors the field digital and analog parameters and transmits data to the Central Monitoring Station. It contains setup software to connect data input streams to data output streams, define communication protocols, and troubleshoot installation problems.

RTUAn RTU(sometimes referred to as a remote

telemetry unit) as the title implies, is a standalone data acquisition and control unit, generally microprocessor based, which monitors and controls equipment at some remote location from the central station.

RTUs differ from programmable logic controllers (PLCs) in that RTUs are more suitable for wide geographical telemetry.

RTUs, PLCs and DCS are increasingly beginning to overlap in responsibilities, and many vendors sell RTUs with PLC-like features and vice versa.

Comparison with other control systems

Remote monitoring and control of functions and instrumentation for:

Hydro-graphic (water supply, reservoirs, sewerage systems).

Electrical power transmission networks and associated equipment.

Natural gas networks and associated equipment.

Outdoor warning sirens.

Applications of RTU

47

PLC PLC – Programmable Logic Controller

Ladder logic Industrial computer that replaced relaysCannot control IEDs Communication compatibilities Takes actions based on its inputs

Components of SCADA System

Features of SCADADynamic process graphicReal-time and Historical trendingAlarmsRecipe ManagementSecurityDevice connectivityScript for logic developmentDatabase connectivityNetworking

1. Dynamic Process Graphics

The graphics can include reactors, valves, pumps, agitators, conveyors as well as other equipment and machinery used in the plant.

Typically the SCADA software will have many ready to use symbols for proper representation which can be used in any type of industry.

2. Real-time & Historical Trends

Real-time data will plot the real-time value for fixed period of time while historical data will have historical data stored value which can be viewed on demand.

The trend play very important role in the process operation. If your batch fails or the plant trips, you can simply go to the historical trend data and do the analysis.

3. Alarms

Alarms represent warnings of process conditions that could cause problems, and require an operator response

have a very critical role in automation. Generally we have alarm states for each inputs/outputs. . Most of the SCADA software support four types of alarms like LOLO,LO,HI and HIHI.

4. Recipe Management

When you have different products to manufacture, you just have to load the recipe of the particular product.

The recipe can be stored in a single server and it can be fetched by any client server from any area to run the process

5. Security Every SCADA software has various levels

of security for securing the application by avoiding unauthorized access

Depending upon the access level given the operator/engineers is allowed to do the task. In most of the cases, operators are allowed only to operate the plant while maintenance engineers can do the application modifications

6. Device Connectivity Every control hardware has its own

communication protocol for communicating with different hardware/software. Some of the leading communication protocol include Modbus, Profibus, Ethernet, Dh+, DH485, Devicenet, Controlnet.

The SCADA software needs device driver software for communication with PLC or other control hardware.

7. Database ConnectivityIn many plants, it is important to

download the real-time information to the MIS. In this case the database connectivity is must.

Many SCADA software don’t have their own database. Hence for storage and reporting they use third party database like MS Access or SQL

8. ScriptsScript is a way of writing logic in SCADA software.

Every SCADA software has its own instructions and way of writing program.

Using scripts, one can develop complex applications. You can create your own functions to suit the process requirement and execution.

9. NetworkingIn many applications, we have to use

more than one SCADA software/operator stations. This can be achieved by taking the SCADA node on network.

In many cases Ethernet TCP/IP is commonly used for networking.

SCADA Architectures

Three generation of SCADA systems:

First generation – MonolithicSecond generation – DistributedThird generation – Networked

Monolithic

Thus SCADA systems were independent systems with no connectivity to other systems. Wide Area Networks were later designed by RTU vendors to communicate with the RTU.

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 system.

Monolithic SCADA System

First Generation SCADA Architecture

Distributed

The processing was distributed across multiple stations which were connected through a LAN and they shared information in real time.

Each station was responsible for a particular task thus making the size and cost of each station less than the one used in First Generation.

Distributed SCADA System

Second Generation SCADA Architecture

Networked

Due to the usage of standard protocols and the fact that many networked SCADA systems are accessible from the Internet, the systems are potentially vulnerable to remote attack.

Networked SCADA System

Third Generation SCADA Architecture

Leading SCADA SoftwareWonderware : InTouch Intellution : iFix (Earlier Fix DMACS) Allen Bradley : RS View (Earlier Control

View) Siemens : WinCC (Earlier Coros LS /B ) GE Fanuc : Cimplicity Indusoft : I W S Movicon : Progea

SCADA Protocols

The transmission of information (both directions) between the master station and RTUs using time division multiplexing techniques requires the use of serial digital messages.

These messages must be efficient.

Protocols:

MODBUS DNP 3.0 Fieldbus Controller Area Network (CAN) Profibus DirectNet TCP/IP EthernetIEC 60870 -5

SCADA VENDORSConitel, Profibus, Modbus RTU and RP-570.

Standard protocols are IEC 61850, DNP3 and IEC 60870-5-101 or 104. These protocols are recognized and standardized by all big SCADA vendors. Several of these protocols have extensions for operating through the TCP/IP.

Security & Vulnerability of SCADA System

Threats to SCADA Systems:1. Foreign Intelligence Services2. Insiders3. Spammers(hackers)4. Spyware/malware authors(viruses)

Security & Vulnerability

Security & VulnerabilityDeploying SCADA Security Strategies:Boarder router and firewallProxy serverOperating systemApplicationPolicies and ProceduresScada firewall

Boarder Router and FirewallsProperly configured and coordinated, can

protect passwords, IP addresses, files and more.

Hardened operating system

Proxy ServersIs an internet server that acts as a

firewall, mediating traffic between a protected network and the internet.

ApplicationsApplication layer attacks; i.e., buffer

overruns, worms, trojan horse program and malicious Active-X5 code, can incapacitate anti-virus software and bypass the firewall as if it wasn’t even there.

Operating SystemsCore of every computer system.Design level migration to new and

improved operating system.

Policies and ProceduresConstitute the foundation of security

policy infrastructures.Passwords Help protect the SCADA network in

conjunction with the corporate network

Scada firewall

Strong firewall protection to wall off your SCADA networking systems from both internal corporate network and the internet be implemented.

Security & Vulnerability

Documented IncidentsNortheast Power Blackout

In August 2003, failure of the alarm processor in First Energy’s SCADA system prevented control room operators from having adequate situational awareness of critical operational changes to the electrical grid.

Thanks for Listening

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