SCADA is the abbreviation for Supervisory Control And Data Acquisition. It generally refers to an industrial control system which is meant to function across a wide area with an autonomous Remote Terminal Unit (RTU). The precise definition of SCADA has been muddied somewhat by newer telecommunications technology, enabling reliable, low latency, high speed communications over wide areas, and a tendency by popular media to mistakenly refer to all Industrial Control Systems as SCADA. Despite this confusion, a SCADA system is expected to have open loop controls (meaning that a human operator watches near real time data and issues commands). By comparison, a Distributed control system (DCS) is expected to have closed loop controls (meaning that real-time loop data is applied directly to an industrial controller without human intervention). These differences are primarily design philosophies, not mandates of definition.

The supervisory control system is a system that sends commands to a real-time control system to control a process that is external to the SCADA system (i.e. a computer, by itself, is not a SCADA system even though it controls its own power consumption and cooling). This implies that the system coordinates, but does not control processes in real time, as there is a separate or integrated real-time automated control system that can respond quickly enough to compensate for process changes within the time constants of the process. The process can be industrial, infrastructure or facility based as described below:

Industrial processes include those of manufacturing, production, power generation, fabrication, and refining, and may run in continuous, batch, repetitive, or discrete modes.

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, and large communication systems.

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.

Contents

[hide] 1 Systems concepts 2 Human Machine Interface 3 Hardware solutions 4 System components

o 4.1 Remote Terminal Unit (RTU) o 4.2 Master Station

4.2.1 Operational philosophy o 4.3 Communication infrastructure and methods

5 Trends in SCADA 6 Security issues

7 References

8 See also

[edit] Systems concepts

SCADA systems, a branch of instrumentation engineering, include input-output signal hardware, controllers, human-machine interfacing ("HMI"), networks, communications, databases, and software.

The term SCADA usually refers to centralized systems which monitor and control entire sites, or complexes of systems spread out over large areas (on the scale of kilometers or miles). Most site control is performed automatically by remote terminal units ("RTUs") or by programmable logic controllers ("PLCs"). Host control functions are usually restricted to basic site overriding or supervisory level intervention. For example, a PLC may control the flow of cooling water through part of an industrial process, but the SCADA system may allow operators to change the set points for the flow, and enable alarm conditions, such as loss of flow and high temperature, to be displayed and recorded. The feedback control loop passes through the RTU or PLC, while the SCADA system monitors the overall performance of the loop.

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. Data may also be fed to a Historian, often built on a commodity Database Management System, to allow trending and other analytical auditing.

SCADA systems typically implement a distributed database, commonly referred to as a tag database, which contains data elements called tags or points. A point represents a single input or output value monitored or controlled by the system. Points can be either "hard" or "soft". A hard point represents an actual input or output within the system, while a soft point results from logic and math operations applied to other points. (Most implementations conceptually remove the distinction by making every property a "soft" point expression, which may, in the simplest case, equal a single hard point.) Points are normally stored as value-timestamp pairs: a value, and the timestamp when it was recorded or calculated. A series of value-timestamp pairs gives the history of that point. It's also common to store additional metadata with tags, such as the path to a field device or PLC register, design time comments, and alarm information.

[edit] Human Machine Interface

A Human-Machine Interface or HMI is the apparatus which presents process data to a human operator, and through which the human operator controls the process.

The HMI industry was essentially born out of a need for a standardized way to monitor and to control multiple remote controllers, PLCs and other control devices. While a PLC does provide automated, pre-programmed control over a process, they are usually distributed across a plant, making it difficult to gather data from them manually. Historically PLCs had no standardized way to present information to an operator. The SCADA system gathers information from the PLCs and other controllers via some form of network, and combines and formats the information. An HMI may also be linked to a database, to provide trending, diagnostic data, and management information such as scheduled maintenance procedures, logistic information, detailed schematics for a particular sensor or machine, and expert-system troubleshooting guides. Since about 1998, virtually all major PLC manufacturers have offered integrated HMI/SCADA systems, many of them using open and non-proprietary communications protocols. Numerous specialized third-party HMI/SCADA packages, offering built-in compatibility with most major PLCs, have also entered the market, allowing mechanical engineers, electrical engineers and technicians to configure HMIs themselves, without the need for a custom-made program written by a software developer.

SCADA is popular, due to its compatibility and reliability. It is used in small applications, like controlling the temperature of a room, to large applications, such as the control of nuclear power plants.

[edit] Hardware solutions

SCADA solutions often have Distributed Control System (DCS) components. Use of "smart" RTUs or PLCs, which are capable of autonomously executing simple logic processes without involving the master computer, is increasing. A functional block programming language, IEC 61131-3, is frequently used to create programs which run on these RTUs and PLCs. Unlike a procedural language such as the C programming language or FORTRAN, IEC 61131-3 has minimal training requirements by virtue of resembling historic physical control arrays. This allows SCADA system engineers to perform both the design and implementation of a program to be executed on an RTU or PLC.

[edit] System components

The three components of a SCADA system are:

1. Multiple Remote Terminal Units (also known as RTUs or Outstations). 2. Master Station and HMI Computer(s). 3. Communication infrastructure

[edit] Remote Terminal Unit (RTU)

The RTU connects to physical equipment, and reads status data such as the open/closed status from a switch or a valve, reads measurements such as pressure, flow, voltage or current. By sending signals to equipment the RTU can control equipment, such as opening or closing a switch or a valve, or setting the speed of a pump.

The RTU can read digital status data or analog measurement data, and send out digital commands or analog setpoints.

An important part of most SCADA implementations are alarms. An alarm is a digital status point that has either the value NORMAL or ALARM. Alarms can be created in such a way that when their requirements are met, they are activated. An example of an alarm is the "fuel tank empty" light in a car. The SCADA operator's attention is drawn to the part of the system requiring attention by the alarm. Emails and text messages are often sent along with an alarm activation alerting managers along with the SCADA operator.

Quality SCADA RTUs have these characteristics:

Data Networking capability Data Reliability Data Security.

[edit] Master Station

The term "Master Station" refers to the servers and software responsible for communicating with the field equipment (RTUs, PLCs, etc), and then to the HMI software running on workstations in the control room, or elsewhere. In smaller SCADA systems, the master station may be composed of a single PC. In larger SCADA systems, the master station may include multiple servers, distributed software applications, and disaster recovery sites. To increase the integrity of the system the multiple servers will often be configured in a dual-redundant or hot-standby formation providing continuous control and monitoring in the event of a server failure.

The SCADA system usually presents the information to the operating personnel graphically, in the form of a mimic diagram. This means that the operator can see a schematic representation of the plant being controlled. For example, a picture of a pump connected to a pipe can show the operator that the pump is running and how much fluid it is pumping through the pipe at the moment. The operator can then switch the pump off. The HMI software will show the flow rate of the fluid in the pipe decrease in real time. Mimic diagrams may consist of line graphics and schematic symbols to represent process elements, or may consist of digital photographs of the process equipment overlain with animated symbols.

The HMI package for the SCADA system typically includes a drawing program that the operators or system maintenance personnel use to change the way these points are represented in the interface. These representations can be as simple as an on-screen traffic

light, which represents the state of an actual traffic light in the field, or as complex as a multi-projector display representing the position of all of the elevators in a skyscraper or all of the trains on a railway. Initially, more "open" platforms such as Linux were not as widely used due to the highly dynamic development environment and because a SCADA customer that was able to afford the field hardware and devices to be controlled could usually also purchase UNIX or OpenVMS licenses. Today, all major operating systems are used for both master station servers and HMI workstations.

[edit] Operational philosophy

Instead of relying on operator intervention, or master station automation, RTUs may now be required to operate on their own to control tunnel fires or perform other safety-related tasks. The master station software is required to do more analysis of data before presenting it to operators including historical analysis and analysis associated with particular industry requirements. Safety requirements are now being applied to the system as a whole and even master station software must meet stringent safety standards for some markets.

For some installations, the costs that would result from the control system failing is extremely high. Possibly even lives could be lost. Hardware for SCADA systems is generally ruggedized to withstand temperature, vibration, and voltage extremes, but in these installations reliability is enhanced by having redundant hardware and communications channels. A failing part can be quickly identified and its functionality automatically taken over by backup hardware. A failed part can often be replaced without interrupting the process. The reliability of such systems can be calculated statistically and is stated as the mean time to failure, which is a variant of mean time between failures. The calculated mean time to failure of such high reliability systems can be on the order of centuries.

[edit] Communication infrastructure and methods

SCADA systems have traditionally used combinations of radio and direct serial or modem connections to meet communication requirements, although Ethernet and IP over SONET is also frequently used at large sites such as railways and power stations. The remote management or monitoring function of a SCADA system is often referred to as telemetry.

This has also come under threat with some customers wanting SCADA data to travel over their pre-established corporate networks or to share the network with other applications. The legacy of the early low-bandwidth protocols remains, though. SCADA protocols are designed to be very compact and many are designed to send information to the master station only when the master station polls the RTU. Typical legacy SCADA protocols include Modbus, RP-570 and Conitel. These communication protocols are all SCADA-vendor specific. Standard protocols are IEC 60870-5-101 or 104, IEC 61850, Profibus and DNP3. These communication protocols are standardized and recognized by all major SCADA vendors. Many of these protocols now contain extensions to operate over

TCP/IP, although it is good security engineering practice to avoid connecting SCADA systems to the Internet so the attack surface is reduced.

RTUs and other automatic controller devices were being developed before the advent of industry wide standards for interoperability. The result is that developers and their management created a multitude of control protocols. Among the larger vendors, there was also the incentive to create their own protocol to "lock in" their customer base. A list of automation protocols is being compiled here.

Recently, OLE for Process Control (OPC) has become a widely accepted solution for intercommunicating different hardware and software, allowing communication even between devices originally not intended to be part of an industrial network.

Other protocols such as Modbus TCP/IP have become widely accepted and are now the standard for many hardware manufacturers.

[edit] Trends in SCADA

There is a trend for PLC and HMI/SCADA software to be more "mix-and-match". In the mid 1990s, the typical DAQ I/O manufacturer supplied equipment that communicated using proprietary protocols over a suitable-distance carrier like RS-485. End users who invested in a particular vendor's hardware solution often found themselves restricted to a limited choice of equipment when requirements changed (e.g. system expansions or performance improvement). To mitigate such problems, open communication protocols such as IEC870-5-101/104 and DNP 3.0 (serial and over IP) became increasingly popular among SCADA equipment manufacturers and solution providers alike. Open architecture SCADA systems enabled users to mix-and-match products from different vendors to develop solutions that were better than those that could be achieved when restricted to a single vendor's product offering.

Towards the late 1990s, the shift towards open communications continued with individual I/O manufacturers as well, who adopted open message structures such as Modicon MODBUS over RS-485. By 2000, most I/O makers offered completely open interfacing such as Modicon MODBUS over TCP/IP.

SCADA systems are coming in line with standard networking technologies. Ethernet and TCP/IP based protocols are replacing the older proprietary standards. Although certain characteristics of frame-based network communication technology (determinism, synchronization, protocol selection, environment suitability) have restricted the adoption of Ethernet in a few specialized applications, the vast majority of markets have accepted Ethernet networks for HMI/SCADA.

"Next generation" protocols such as OPC-UA, Wonderware's Archestra, and Rockwell Automation's FactoryTalk, take advantage of XML, web services, and other modern web technologies, making them more easily IT supportable.

SCADA systems are becoming increasingly ubiquitous. Thin clients, web portals, and web based products are gaining popularity with most major vendors. The increased convenience of end users viewing their processes remotely introduces security considerations.

[edit] Security issues

The move from proprietary technologies to more standardized and open solutions together with the increased number of connections between SCADA systems and office networks and the Internet has made them more vulnerable to attacks. Consequently, the security of SCADA-based systems has come into question as they are increasingly seen as extremely vulnerable to cyberwarfare/cyberterrorism attacks.[1] [2]

In particular, security researchers are concerned about:

the lack of concern about security and authentication in the design, deployment and operation of existing SCADA networks

the mistaken belief that SCADA systems have the benefit of security through obscurity through the use of specialized protocols and proprietary interfaces

the mistaken belief that SCADA networks are secure because they are purportedly physically secured

the mistaken belief that SCADA networks are secure because they are supposedly disconnected from the Internet

Due to the mission-critical nature of a large number of SCADA systems, such attacks could, in a worst case scenario, cause massive financial losses through loss of data or actual physical destruction, misuse or theft, even loss of life, either directly or indirectly. Whether such concerns will cause a move away from the use of existing SCADA systems for mission-critical applications towards more secure architectures and configurations remains to be seen, given that at least some influential people in corporate and governmental circles believe that the benefits and lower initial costs of SCADA based systems still outweigh potential costs and risks.[citation needed] Recently, multiple security vendors, such as Byres Security, Inc., Industrial Defender Inc., Check Point and Innominate, and N-Dimension Solutions have begun to address these risks by developing lines of specialized industrial firewall and VPN solutions for TCP/IP-based SCADA networks.

Also, the ISA Security Compliance Institute (ISCI) is emerging to formalize SCADA security testing starting as soon as 2009. ISCI is conceptually similar to private testing and certification that has been performed by vendors since 2007, such as the Achilles certification program from Wurldtech Security Technologies, Inc. and MUSIC certification from Mu Security, Inc. Eventually, standards being defined by ISA SP99 WG4 will supersede these initial industry consortia efforts, but probably not before 2011.

[edit] References

1. ̂ D. Maynor and R. Graham. SCADA Security and Terrorism: We're Not Crying Wolf. 2. ̂ Robert Lemos (2006-07-26). SCADA system makers pushed toward security.

SecurityFocus. Retrieved on 2007-05-09.

[1] UK SCADA security guidelines

[edit] See also

Industrial Control Systems Telemetry

Retrieved from "http://en.wikipedia.org/wiki/SCADA"Categories: Telemetry | Automation | Industrial computingHidden categories: Articles needing additional references from January 2008 | All articles with unsourced statements | Articles with unsourced statements since May 2007

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SCADA is an acronym that 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.

SCADA is a term that is used broadly to portray control and management solutions in a wide range of industries. Some of the industries where SCADA is used are Water Management Systems, Electric Power, Traffic Signals, Mass Transit Systems, Environmental Control Systems, and Manufacturing Systems.

SCADA as a System

There are many parts of a working SCADA system. A SCADA system usually includes signal hardware (input and output), controllers, networks, user interface (HMI), communications equipment and software. All together, the term SCADA refers to the entire central system. The central system usually monitors data from various sensors that are either in close proximity or off site (sometimes miles away).

For the most part, the brains of a SCADA system are performed by the Remote Terminal Units (sometimes referred to as the RTU). The Remote Terminal Units consists of a programmable logic converter. The RTU are usually set to specific requirements, however, most RTU allow human intervention, for instance, in a factory setting, the RTU might control the setting of a conveyer belt, and the speed can be changed or overridden at any time by human intervention. In addition, any changes or errors are usually automatically logged for and/or displayed. Most often, a SCADA system will monitor and make slight changes to function optimally; SCADA systems are considered closed loop systems and run with relatively little human intervention.

One of key processes of SCADA is the ability to monitor an entire system in real time. This is facilitated by data acquisitions including meter reading, checking statuses of sensors, etc that are communicated at regular intervals depending on the system. Besides the data being used by the RTU, it is also displayed to a human that is able to interface with the system to override settings or make changes when necessary.

SCADA can be seen as a system with many data elements called points. Usually each point is a monitor or sensor. Usually points can be either hard or soft. A hard data point can be an actual monitor; a soft point can be seen as an application or software calculation. Data elements from hard and soft points are usually always recorded and logged to create a time stamp or history

User Interface (HMI)

A SCADA system includes a user interface, usually called Human Machine Interface (HMI). The HMI of a SCADA system is where data is processed and presented to be

viewed and monitored by a human operator. This interface usually includes controls where the individual can interface with the SCADA system.

HMI's are an easy way to standardize the facilitation of monitoring multiple RTU's or PLC's (programmable logic controllers). Usually RTU's or PLC's will run a pre programmed process, but monitoring each of them individually can be difficult, usually because they are spread out over the system. Because RTU's and PLC's historically had no standardized method to display or present data to an operator, the SCADA system communicates with PLC's throughout the system network and processes information that is easily disseminated by the HMI.

HMI's can also be linked to a database, which can use data gathered from PLC's or RTU's to provide graphs on trends, logistic info, schematics for a specific sensor or machine or even make troubleshooting guides accessible. In the last decade, practically all SCADA systems include an integrated HMI and PLC device making it extremely easy to run and monitor a SCADA system.

SCADA Software and Hardware Components

SCADA systems are an extremely advantageous way to run and monitor processes. They are great for small applications such as climate control or can be effectively used in large applications such as monitoring and controlling a nuclear power plant or mass transit system.

SCADA can come in open and non proprietary protocols. Smaller systems are extremely affordable and can either be purchased as a complete system or can be mixed and matched with specific components. Large systems can also be created with off the shelf components. SCADA system software can also be easily configured for almost any application, removing the need for custom made or intensive software development.

Books on SCADA

Practical Modern SCADA

SCADA (Supervisory Control and Data Acquisition) systems are at the heart of the modern industrial enterprise ranging from mining plants, water and electrical utility installations to oil and gas plants. In a market that is crowded with high-level monographs and reference guides, more practical information for professional engineers is required. This book covers the essentials of SCADA communication systems focussing on DNP3, the IEC 60870.5 standard and other new developments in this area. It commences with a brief review of the

Protocols: DNP3, 60870.5 and Related Systems

fundamentals of SCADA systems' hardware, software and the communications systems (such as RS-232, RS-485, Ethernet and TCP/IP) that connect the SCADA Modules together. A solid review is then done on the DNP3 and IEC 60870.5 protocols where its features, message structure, practical benefits and applications are discussed. This book provides you with the knowledge to design your next SCADA system more effectively with a focus on using the latest communications technologies available.

Covers the essentials of SCADA communication systems and other new developments in this area

Covers a wide range of specialist networking topics and other topics ideal for practicing engineers and technicians looking to further and develop their knowledge of the subject

Extremely timely subject as the industry has made a strong movement towards standard protocols in modern SCADA communications systems

Practical SCADA for Industry

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. 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.

An engineer's introduction to Supervisory Control and Data Acquisition (SCADA) systems and their application in monitoring and controlling equipment and industrial plant

Essential reading for data acquisition and control professionals in plant engineering, manufacturing, telecommunications, water and waste control, energy, oil and gas refining and transportation

Provides the knowledge to analyse, specify and debug SCADA systems, covering the fundamentals of hardware, software and the communications systems that connect SCADA operator stations

SCADA: Supervisory Control and Data Acquisition

Supervisory control and data acquisition (SCADA) technology has evolved over the past 30 years as a method of monitoring and controlling large processes. This newly revised reference book offers overviews of SCADA's component technologies, as well as details necessary to understand the big picture. SCADA processes cover areas that may be measured in the thousands of square miles, and have dimensions that may be hundreds, occasionally thousands, of miles long. Now a mature technology, SCADA includes, but is not limited to, software packages that can be incorporated in a larger system. After completing its 14 self-study units, readers should be conversant with SCADA nomenclature and architecture, understand the basic technology of the system's building blocks, understand its limitations, understand how it can benefit particular operations, and have a basis for selecting appropriate SCADA technologies for their operational requirements.

Bookmark What is SCADA?

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SCADA

Penulis:Waskita Indrasutanta, (acting) Systems Department Head - Wifgasindo

Dinamika Instrument Engineering

SCADA (Supervisory Control And Data Acquisition) adalah suatu Sistem Kontrol Supervisory dan Pengumpul. Pada prakteknya pengumpul data umumnya adalah data dari Site di lokasi ‘remote’, atau sering disebut sebagai ‘Telemetry’, dan Supervisory Control pada Site di lokasi ‘remote’ pula, atau sering disebut ‘Telecontrol’. Supervisory Control adalah kendali yang dilakukan diatas kendali lokal, sebagai contoh, pada oil production kita mempunyai beberapa production site yang dikumpulkan pada stasiun pengumpul ( gathering station ). Kendali lokal dilakukan untuk masing-masing production well dan supervisory control di stasiun pengumpul, melakukan control kepada semua production well dibawahnya. Misalnya, salah satu production well mengalami gangguan, dan stasiun pengumpul tetap harus memberikan dengan production rate tertentu, maka supervisory control akan melakukan koordinasi pada production well lainnya agar jumlah produksi bisa tetap dipertahankan.

Istilah SCADA, DCS, FCS dan PLC saat ini sudah menjadi agak kabur karena aplikasi yang saling tumpang tindih. Walaupun demikian kita masih bisa membedakan dari arsitektur-nya yang serupa tapi tak sama. Sesuai dengan rancang bangun awalnya, DCS lebih berfungsi baik untuk aplikasi kontrol proses, sedangkan SCADA lebih berfungsi baik untuk aplikasi seperti istilah diterangkan diatas.

Sensor, Transmitter dan Actuator yang dipergunakan SCADA sama saja dengan yang dipergunakan DCS, FCS, dan PLC, dengan standard 4~20mA, HART, Fieldbus, dsb., sesuai dengan kompatibilitas SCADA System yang dipergunakan. Ada beberapa pabrikan yang membuat MV ( Multi Variable ) Transmitter, yang langsung menggunakan Modbus, sehingga dengan menambah Radio Modem, transmitter ni menjadi sebuah RTU. Arsitekturnya terdiri sebuah MTU ( Master Terminal Unit ) dengan Operator Workstation, dan pada remote location terdapat RTU ( Remote Terminal Unit ). Dengan teknologi saat ini, arsitektur SCADA mulai berubah dan sering disebut sebagai ‘Remote Application Control System’ .

SCADA telah mengalami perubahan generasi, dimana pada awalnya design sebuah SCADA mempunyai satu perangkat MTU yang melakukan Supevisory Control dan

Data Acquisition melalui satu atau banyak RTU yang berfungsi sebagai (dumb) Remote I/O melalui jalur komunikasi Radio, dedicated line Telephone dan lainnya.

Generasi berikutnya, membuat RTU yang intelligent, sehingga fungsi local control dilakukan oleh RTU di lokasi masing-masing RTU, dan MTU hanya melakukan supervisory control yang meliput beberapa atau semua RTU. Dengan adanya local control, operator harus mengoperasikan masing-masing local plant dan membutuhkan MMI local. Banyak pabrikan yang mengalihkan komunikasi dari MTU - RTU ke tingkatan MMI (Master) - MMI (Remote) melalui jaringan microwave atau satelit. Ada juga yang mengimplementasi komunikasinya pada tingkatan RTU, karena berpendapat bahwa kita tidak bisa mengandalkan system pada Computer, dan komunikasi pada tingkatan Computer (MMI) membutuhkan bandwidth yang lebar dan mahal.

Dengan majunya teknologi Intranet dan Internet saat ini, concept SCADA diatas berubah menjadi lebih sederhana dan memanfaatkan infrastruktur Intranet yang pada saat ini umumnya sudah dibangun oleh perusahaan-perusahaan besar seperti Pertamina. Apabila ada daerah-daerah atau wilayah yang belum terpasang infrastruktur Intranet, saat ini dipasaran banyak bisa kita dapatkan Wireless LAN device yang bisa menjangkau jarak sampai dengan 40 km (tanpa repeater) dengan harga relatif murah.

Setiap Remote Area dengan sistem kontrolnya masing-masing yang sudah dilengkapi dengan OPC (OLE for Process Control; OLE = Object Linking & Embedding) Server, bisa memasangkan suatu Industrial Web Server dengan Teknologi XML yang kemudian bisa dengan mudah di akses dengan Web Browser biasa seperti yang kita gunakan untuk Internet Browsing seperti MS Internet Explorer, Netscape, dsb. Dari Web Browser ini kita bisa mendapatkan semua tampilan seperti pada layar MMI local, atau dibuatkan tampilan sendiri sesuai kebutuhan. Kontrol tetap bisa dilakukan melalui Web Browser ini sebagaimana layaknya MMI di lokasi local.

Untuk sekuriti, system harus kita lengkapi dengan Router yang hanya mem-publish Web Server ke WAN (Wide Area Network) untuk mengisolir hacker untuk mengganggu Control System pada Control Network kita di lokasi masing-masing. Industrial Web Server juga dilengkapi dengan banyak sekali fasilitas sekuriti, seperti login name dengan password, menentukan komponen mana yang perlu di-publish dan mana yang ‘read only’, mana yang bisa dilakukan ‘control’ dari remote, dan sebagainya.

System seperti ini populer dengan sebutan Remote Application Control System (RACS), yang makin digemari orang, karena sebenarnya hal seperti inilah yang dibutuhkan pada waktu kita akan memasangkan suatu SCADA system. Idealnya, seluruh Pertamina mulai dari EP dengan TMG-nya, UP dengan banyak Unit Daerahnya, PDN dengan jaringan Distribusi dan Pemasarannya, dengan mudah bisa di-integrasikan melalui teknologi Intranet dan Internet. Bahkan kita bisa me-launch Web Server kita ke jaringan Internet yang otomatis bisa kita akses dari manapun di seluruh dunia.

SCADA adalah suatu sistem pengendalian alat secara jarak jauh, dengan

kemampuan memantau data-data dari alat yang dikendalikan. SCADA merupakan bidang

yang secara kontinyu selalu dikembangkan di seluruh bagian dunia pada berbagai tipe

industri yang menghabiskan bertrilyun-trilyun rupiah.

Penelitian-penelitian mengenai SCADA semakin berkembang dengan

ditemukannya media komunikasi bergerak, sehingga memunculkan istilah Mobile

SCADA.

Salah satu penelitian untuk mengatasi permasalahan di atas adalah dengan

dibuatnya suatu sistem SCADA yang dikendalikan melalui web (Robotics and

Automation Group, 2004). Di dalam penelitian ini digunakan sebuah server yang

terkoneksi dengan internet yang akan menangani beberapa fungsi dan kontrol robot.

Dengan dipindahkannya beberapa fungsi dan kontrol tersebut maka fungsi pengendalian

robot akan menjadi lebih sederhana, yang berakibat pula sistem bersifat generik, artinya

bisa diterapkan di berbagai bidang aplikasi industri. Selain itu juga dibuat program

berbasis web yang bersifat user friendly. Hal-hal ini akan mengatasi beberapa

permasalahan di atas. Namun demikian sistem di atas masih belum bersifat

bergerak/mobile.

Oleh karena itu penelitian-penelitian baru dilakukan dengan merancang suatu

sistem SCADA yang menggunakan teknologi komunikasi bergerak, untuk selanjutnya

kita sebut sebagai Mobile SCADA. Mobile SCADA sendiri didefinisikan sebagai

penggunaan sistem SCADA dengan media komunikasi jaringan telepon bergerak (Mayer,

2002). Dengan digunakannya infrastruktur komunikasi bergerak yang sudah ada tersebut,

maka bisa diwujudkan suatu sistem SCADA yang berbiaya murah, disertai dengan

kemampuannya untuk bisa dipasang di mana saja tanpa tergantung setting lokasi industri.

Selain itu dalam sistem ini juga akan digunakan suatu server terhubung internet yang

akan mengakomodir beberapa fungsi dan kontrol pengendalian sehingga kerumitan

sistem akan terkurangi yang mengakibatkan perangkat SCADA akan dapat dioperasikan

dengan mudah dan lebih bersifat generik serta perawatannya menjadi lebih murah.

Penghematan biaya terjadi karena obyek kendali bisa dikendalikan secara jarak jauh

sehingga akan membantu penghematan kerja manusia.

Namun demikian sistem-sistem SCADA yang dikembangkan di atas syarat

dengan rancang bangun yang modern dan integrasi yang tinggi antara perancang dan

industri pendukungnya. Penelitian-penelitian di atas bahkan membutuhkan biaya yang

juga masih sangat mahal untuk mengembangkan mesin SCADA (lihat Gb.1), yang

merupakan komponen utama dari sistem SCADA yang berupa kartu (card) yang

tersambung ke telepon klien dan ke obyek kendali. Sistem pengembangan alat seperti ini

tentu akan sangat berat bila diterapkan di Indonesia.

Maka dari itu dalam penelitian ini akan dikembangkan suatu sistem SCADA yang

tepat bagi kondisi industri menengah ke bawah di Indonesia, yang bisa dilaksanakan oleh

para peneliti di level universitas di Indonesia, dengan penggunaan komponen-komponen

dan perangkat lunak yang mudah didapatkan di pasaran, serta dengan menggunakan

jaringan komunikasi bergerak yang murah di Indonesia, seperti jaringan CDMA.

Selain permasalahan di atas, ada permasalahan utama yang akan menjadi titik

perhatian dalam penelitian ini, yaitu pembuatan protokol atau aturan-aturan kendali yang

nantinya akan menjadi landasan pembuatan perangkat lunak sistem Mobile SCADA ini.

Protokol ini nantinya harus dibuat sedemikian rupa sehingga perangkat lunak serta

perangkat keras yang dibangun dalam sistem ini dapat mengatasi berbagai permasalahan

di atas, yaitu bersifat generik, mudah digunakan, mudah dirawat, mudah beradaptasi, dan

mobile.

1.2 Keaslian dan Kedalaman

Beberapa penelitian mengenai Mobile SCADA telah dilakukan. Lembaga

penelitian HighBeam Research di Chicago telah mengembangkan sistem ini untuk

keperluan pengendalian sistem pengairan dan sistem pemompaan. Sistem SCADA yang

dikembangkan menggunakan RTUs, suatu perangkat pengendalian dengan media

komunikasi radio. Pada sistem ini terdapat suatu sistem pengendalian berbasis komputer

yang terletak pada sebuah kamar pusat. Sistem seperti ini sangat efektif digunakan untuk

memantau operasi-operasi secara remote, namun pada suatu area yang terbatas. Sistem

ini dilaporkan mampu menghemat biaya secara signifikan karena hemat tenaga manusia

dan hemat energi.

Penelitian lain adalah yang dilakukan lembaga riset CSIRO, Canberra, Australia.

Sistem Mobile SCADA yang dikembangkan menggunakan GPRS sebagai media

komunikasinya dan menggunakan mikroprosesor yang murah untuk mesin SCADA,

sehingga dihasilkan sistem SCADA yang murah dan fleksibel (Mayer dan Taylor, 2002).

Penelitian ini lebih dikhususkan untuk sistem SCADA pada jaringan sensor. Jaringan

sensor adalah suatu sistem yang terdiri dari banyak micro controller kecil yang

mempunyai alat sensor, yang bekerja bersama pada jaringan nirkabel.

Penelitian yang dikerjakan pada tesis ini dimaksudkan untuk mengembangkan

suatu sistem Mobile SCADA dengan protokol atau aturan-aturan kendali yang nantinya

akan menjadi landasan bagi pembuatan perangkat lunak sistem. Protokol ini nantinya

harus dibuat sedemikian rupa sehingga perangkat lunak serta perangkat keras yang

dibangun dalam sistem ini bersifat generik, mudah digunakan, mudah dirawat, mudah

beradaptasi, dan mobile sehingga tepat digunakan oleh industri menengah ke bawah di

Indonesia. Selain itu sistem Mobile SCADA ini menggunakan media komunikasi Paket

Data CDMA.

1.3 Manfaat

Dengan sistem Mobile SCADA yang dibuat dengan suatu protokol/aturan yang

didasarkan pada kondisi ketersediaan komponen-komponen mesin SCADA di Indonesia,

serta didasarkan pada perangkat lunak yang murah bahkan gratis, dan dibatasi untuk

permasalahan sederhana dan bersifat umum atau generik, serta dengan menggunakan

media komunikasi Paket Data CDMA di Indonesia, maka akan dihasilkan sebuah sistem

Mobile SCADA yang akan sangat sesuai dengan kebutuhan industri-industri di Indonesia

yang ingin menerapkan sistem SCADA. Tentu saja pemanfaatan hasil penelitian masih

harus disesuaikan dengan bidang aplikasi yang akan menggunakannya, yaitu dengan

sedikit modifikasi pada perangkat lunaknya karena menyesuaikan perangkat keras yang

akan dikendalikan.

II TUJUAN

Tujuan utama dari penelitian ini adalah membuat suatu sistem Mobile SCADA

yang bersifat generik, mudah digunakan, mudah dirawat, mudah beradaptasi, dan mobile,

sehingga bisa digunakan oleh industri menengah ke bawah di Indonesia. Hal ini bisa

dicapai bila pembuatan protokol atau aturan-aturan kendali dalam sistem tersebut yang

disesuaikan dengan kondisi perangkat keras dan perangkat lunak yang akan digunakan,

yaitu yang banyak tersedia di Indonesia, serta disesuaikan dengan media komunikasinya

yang murah yaitu Paket Data CDMA.

Tujuan kedua adalah melakukan uji coba terhadap sistem Mobile SCADA yang

dihasilkan. Uji coba akan dilakukan pada suatu obyek kendali yang berupa motor-motor

industri sederhana. Variabel-variabel yang akan diteliti meliputi waktu respon obyek

kendali, biaya komunikasi data, serta kehandalan sistem.

III TINJAUAN PUSTAKA DAN LANDASAN TEORI

3.1 Tinjauan Pustaka

Lembaga penelitian HighBeam Research di Chicago telah mengembangkan

sistem Mobile SCADA dengan menggunakan RTUs, suatu perangkat pengendalian

dengan media komunikasi radio (May, 1997). Penelitian serupa dilakukan juga oleh

Perusahaan MDS di Rochester, New York.

Penelitian lain adalah yang dilakukan lembaga riset CSIRO, Canberra, Australia.

Sistem Mobile SCADA yang dikembangkan menggunakan GPRS sebagai media

komunikasinya dan menggunakan mikroprosesor yang murah untuk mesin SCADA,

sehingga dihasilkan sistem SCADA yang murah dan fleksibel (Mayer dan Taylor, 2002).

Penelitian-penelitian di atas memerlukan suatu mesin SCADA yang

membutuhkan rancang bangun yang modern dan integrasi yang tinggi antara industri

pendukung dan perancangnya. Hal ini belum bisa dilakukan di Indonesia. Sehingga

dalam tesis ini akan dibuat suatu protokol atau aturan-aturan kendali yang nantinya akan

menjadi landasan pembuatan perangkat lunak sistem Mobile SCADA ini. Protokol ini

nantinya harus dibuat sedemikian rupa sehingga perangkat lunak serta perangkat keras

yang dibangun dalam sistem ini dapat mengatasi berbagai permasalahan di atas, yaitu

bersifat generik, mudah digunakan, mudah dirawat, mudah beradaptasi, dan mobile.

Selain itu penelitian pada tesis ini menggunakan media komunikasi yang berbeda dengan

penelitian-penelitian di atas, yaitu Paket Data CDMA.

Agar sistem Mobile SCADA yang dikembangkan bersifat generik, mudah

digunakan, mudah dirawat, dan mudah beradaptasi, maka pembuatan sistem SCADA

perlu memisahkan pengembangan fungsional dan layanan ke dalam dunia komputasi

umum (DKU) dan dunia alat kendali (Taylor dan Palmer, 2003). Untuk lebih jelasnya

bisa dilihat pada Gb.1. Hal ini dilakukan dengan membagi-bagi sistem ke dalam tiga

modul, yaitu Front End, Back End, dan mesin SCADA (lihat Gb.6). Front End adalah

antar muka web bagi sistem SCADA yang akan dikembangkan yang berguna

menghindari kekompleksan bagi pengguna sistem. Di dalam Front End terdapat

fungsionalitas sistem yang mewakili fungsi-fungsi pengendalian. Sedangkan Back End

merupakan sebuah program aplikasi yang mengelola koneksi ke mesin SCADA, dan juga

terpasang di PC yang sama (Server Web/Aplikasi) dengan lokasi Front End. Back End

dan mesin SCADA akan memberikan layanan-layanan yang diminta oleh pengguna

melalui Front End. Seorang pengguna dengan mudah bisa mengendalikan obyek kendali

melalui Front End tanpa harus memahami bagaimana Back End dan mesin SCADA

memberikan layanan-layanan yang diminta.

Pengguna dari suatu sistem Mobile SCADA melalui sebuah aplikasi browser web

dengan media komunikasi bergerak akan mengirimkan pesan-pesan ke obyek kendali.

Sebelum pesan-pesan ini sampai maka terlebih dulu harus diterjemahkan oleh suatu

mesin SCADA ke dalam bentuk perintah-perintah (lihat Gb.1). Setelah obyek kendali

mengerjakan perintah-perintah tersebut maka akan ada suatu mekanisme untuk

mendapatkan umpan balik yang menunjukkan bahwa perintah-perintah telah

dilaksanakan. Salah satu caranya adalah dengan digunakannya suatu aplikasi TiniDB.

TiniDB adalah suatu basis data mini yang bisa beroperasi pada mesin SCADA yang

berkomunikasi dengan pengguna dengan teknologi komunikasi bergerak, yang

memungkinkan dilaksanakannya operasi-operasi SQL (Ken Taylor dan Kevin Mayer,

2003).

Penelitian dalam tesis ini tidak menggunakan suatu aplikasi TinyDB, namun

menggunakan sistem basis data yang diimplementasikan pada Server Aplikasi yang

telepon klien

mobil

mesin SCADAInterne

tkoneksi Paket Data

koneksi RS-232 dengan AT+ command

Server Web/Aplikasi

Browser

Basis Data

dunia alat kendali

DKU

CDMA servis provider

Gb.1. Arsitektur Mobile SCADA berbasis Paket Data CDMA

mempunyai IP privat yang terhubung ke mesin SCADA melalui jaringan telepon

bergerak. Dengan penggunaan basis data di server ini maka dengan mudah bisa

ditambahkan fasilitas-fasilitas fungsional yang memungkinkan terjadinya kegenerikan

sistem. Bila sistem ini akan digunakan pada bidang aplikasi industri yang lain, maka kita

tidak perlu mengubah program pada mesin SCADA, namun yang perlu kita ubah adalah

variabel-variabel pada basis data yang terpasang di server aplikasi.

Sistem SCADA yang murah dan fleksibel bisa diperoleh dengan penggunaan

mesin SCADA yang murah, serta dengan menggunakan sarana komunikasi yang sudah

ada, yaitu jaringan telepon bergerak. Sementara itu teknologi GPRS menyediakan suatu

jalur komunikasi yang selalu online namun biayanya tidak berbasis waktu tersambung

(Kevin Mayer dan Ken Taylor, 2002). Dalam penelitian tersebut digunakan suatu mesin

SCADA yang mampu memicu sambungan TCP secara langsung ke suatu PC (yang

merupakan Server Aplikasi dengan alamat IP privat) dengan sarana teknologi GPRS,

sehingga waktu respon dari sistem pengendalian menjadi lebih baik daripada yang

menggunakan mesin SCADA tanpa kemampuan memicu sambungan TCP secara

langsung. Namun demikian mesin SCADA di atas dirancang secara khusus sehingga

harganya pun relatif sangat mahal.

Dalam penelitian, selain digunakan media komunikasi bergerak yang berbeda dan

lebih murah yaitu Paket Data CDMA, yang prinsip umumnya sama dengan media

komunikasi GPRS, juga akan digunakan suatu sistem yang berbeda dari sistem di atas,

yaitu mesin SCADA yang digunakan mudah didapatkan di Indonesia dengan harga

murah, namun tidak akan secara langsung bisa memicu sambungan TCP ke PC Server

Aplikasi. Sambungan TCP hanya terjadi di antara PC dan telepon bergerak. Mesin

SCADA yang tertempeli telepon bergerak tersebut melakukan komunikasi dengan

menggunakan perintah AT+ command (merupakan himpunan teks ASCII dan

berorientasi baris, yang digunakan telepon bergerak untuk membaca pesan IO dari

peralatan lain dengan protokol RS-232, lihat Gb.1). Walaupun terlihat bahwa waktu

respon pengendalian dari sistem ini bertambah, namun dalam penelitian ini akan dicari

suatu cara di mana kekurangan tersebut bisa ditekan seminimal mungkin. Hal ini dapat

dilakukan dengan telepon bergeraknya diprogram agar setiap saat (dalam hitungan mikro

detik) selalu meminta data dari mesin SCADA yang memang sudah tersambung ke PC

melalui sambungan TCP.

Penelitian akan disesuaikan dengan kondisi di Indonesia yang mana akan

dimanfaatkan mesin SCADA yang dibangun dari micro controller yang tersedia mudah

di pasaran seperti Micro Controller AT 89C51, atau micro controller lainnya.

3.2 Landasan Teori

Dengan membuat suatu sistem SCADA yang murah dan dapat diaplikasikan pada

berbagai aplikasi SCADA dengan sedikit pemrograman serta dengan menambahkan

peralatan yang sesuai, akan menghasilkan suatu sistem SCADA yang sangat berguna bagi

berbagai aplikasi industri maupun organisasi.

Biaya yang mahal dari banyak aplikasi SCADA disebabkan oleh penggunaan

sarana komunikasi yang khusus. Dengan digunakannya sarana komunikasi yang sudah

tersedia secara luas, yaitu pada kasus ini adalah jaringan komunikasi bergerak, tidak

hanya harga yang bisa dikurangi, namun juga akan didapatkan sifat skalabilitas dan sifat

generik dari sistem ini. Jaringan komunikasi bergerak yang telah beroperasi di Indonesia

umumnya ada dua macam, yaitu yang menggunakan teknologi GSM yang sudah lebih

dulu ada dan yang menggunakan teknologi CDMA yang lebih murah. Kedua teknologi di

atas sama-sama mempunyai empat metode komunikasi yaitu:

1. Komunikasi Bit Tunggal,

2. SMS,

3. Data Call,

4. GPRS / Paket Data.

Komunikasi Bit Tunggal

Sistem komunikasi ini adalah teknologi paling sederhana yang hanya

menggunakan data satu bit bernilai ”on/off”. Komunikasi terjadi dengan cara pengguna

memanggil sebuah nomor telepon yang merupakan bagian dari sistem PABX yang

terhubung dengan sebuah komputer. Komputer di sini digunakan untuk mengelola sebuah

basis data yang bertugas mencocokkan nomor pemanggil, nomor terpanggil, dan perintah

yang relevan. Contoh aplikasinya adalah beroperasinya suatu vending machine yang

mengeluarkan minuman bila suatu nomor telepon dipanggil. Hal ini dimungkinkan

karena vending machine tadi disambungkan ke komputer yang terhubung ke Internet.

SMS

telepon pengguna

PABXPC Vending

Machine

Gb.2. Komunikasi Bit Tunggal

Sistem komunikasi ini dapat menyediakan lalu lintas data yang lebih besar

dibanding komunikasi bit tunggal, yang menggunakan mode asynchronous namun tanpa

jaminan terkirim. Sebuah komputer yang dengan kabel serial terhubung ke

telepon/modem bergerak dapat digunakan untuk mengotomatisasi pengiriman dan

penerimaan SMS. Dengan cara ini pesan-pesan yang datang dapat dianalisa oleh suatu

program komputer, demikian halnya pesan dapat dibangkitkan pada komputer dan

dikirimkan ke sebuah telepon bergerak.

Data Call

Komunikasi ini memungkinkan lalu lintas data yang besar. Sistem ini meminta

alokasi satu slot untuk setiap percakapan, walaupun pada saat itu tidak ada transfer data.

Begitu suatu percakapan tersambung, akan terjamin bahwa data bisa terkirimkan. Proses

pengiriman data ini menggunakan sistem Data Over Voice, di mana data akan diubah ke

sinyal frekuensi dengan menggunakan DTMF encoder yang nantinya pada telepon

bergerak penerima diubah kembali ke data dengan DTMF decoder. Untuk itu diperlukan

bahasa pemrograman J2ME yang memang memungkinkan proses DTMF

encoder/decoder. Biaya tergantung dari jumlah waktu sambungan percakapan.

Komunikasi ini sangat cocok untuk sistem yang tidak memerlukan data waktu nyata,

serta tidak memerlukan komunikasi yang kontinyu, namun secara khusus sangat cocok

untuk lalu lintas data besar yang memerlukan waktu transfer singkat.

telepon pengguna

PC

modem GPRS

robot

Gb.3. Komunikasi dengan SMS

GPRS atau Paket Data

Sistem komunikasi ini berprinsip bahwa satu slot percakapan sebenarnya bisa

digunakan oleh beberapa pengguna secara simultan dengan time division multiplexing.

Seorang pengguna hanya menggunakan lebar pita saat loading halaman web, bukan saat

membaca halaman yang telah di-load. Biaya tergantung dari jumlah data terkirim, bukan

tergantung dari jumlah waktu sambungan, sehingga sangat cocok untuk sistem yang

memerlukan data waktu nyata, serta memerlukan komunikasi yang kontinyu.

Karakteristik metode komunikasi di atas ditabelkan berikut ini:

Tabel 1. Karakteristik metode komunikasi bergerak.

Metode Harga / KB

(rupiah)

waktu

transfer / KB

Full

duplex

Handal Selalu

online

Bit Tunggal 0 2 jam X V X

telepon pengguna

telepon bergerak

robot

mesin SCADA

telepon pengguna

telepon klien

mobil

mesin SCADAklien

selaludial server

koneksi GPRS/ Paket Data

koneksi RS-232 dengan AT+ command

Server Web/Aplikasi

Gb.4. Komunikasi dengan Data Call

Gb.5. Komunikasi dengan GPRS/Paket Data

SMS 1920 40 detik X X V

Data Call (GSM) 1100 1 detik V V V

Data Call (CDMA) 250 1 detik V V V

GPRS 500 1 second V V V

Paket Data 350 1 second V V V

Perhitungan di atas didapatkan dengan berdasarkan pada data-data dari homepage telkom

flexi, suatu penyedia sambungan telepon bergerak CDMA. Perlu diingat bahwa data tabel

di atas hanya sekedar rata-rata, artinya masing-masing penyedia layanan pasti

menerapkan harga yang berbeda.

Sistem yang Dikembangkan

Dengan adanya data-data untuk keempat metode komunikasi di atas maka

menjadikan masukan mengenai bagaimana sistem SCADA dalam penelitian ini akan

dikembangkan. Dunia industri sangat membutuhkan media komunikasi yang kontinyu,

data waktu nyata, dan murah. Sehingga Paket Data dipilih sebagai metode

komunikasinya. Skema sistem Mobile SCADA yang akan dibuat ditunjukkan pada Gb.1.

Data waktu nyata pada media komunikasi Paket Data ini memang sangat tergantung dari

bandwidth Internet yang dialokasikan untuk Server Web/Aplikasinya. Penelitian oleh

Mayer menunjukkan bahwa sambungan TCP untuk transfer data pada GPRS memerlukan

1 KB/detik (Mayer, 2002). Sedangkan data dari homepage flexi menunjukkan bahwa

transfer data Paket Data juga memerlukan 1 KB/detik. Tentu saja untuk mencapai hal itu

tidak mudah karena seperti telah dijelaskan di Tinjauan Pustaka bahwa mesin SCADA

yang dibuat tidak secara langsung bisa memicu sambungan TCP ke Server Aplikasi.

Sambungan TCP hanya terjadi di antara Server Aplikasi dan telepon bergerak. Mesin

SCADA yang tertempeli telepon klien tersebut melakukan komunikasi dengan

menggunakan perintah AT+ command (merupakan himpunan teks ASCII dan

berorientasi baris, yang digunakan telepon bergerak untuk membaca pesan IO dari

peralatan lain dengan protokol RS-232, lihat Gb.1) sehingga waktu respon pengendalian

dari sistem ini bertambah. Namun demikian dalam penelitian ini akan dicari suatu cara di

mana waktu respon bisa ditekan seminimal mungkin. Hal ini dapat dilakukan dengan

telepon bergeraknya diprogram agar setiap saat (dalam hitungan mikro detik) selalu

meminta data dari mesin SCADA yang memang sudah tersambung ke PC melalui

sambungan TCP.

3.3 Perancangan Sistem

Sistem Mobile SCADA ini akan menggunakan metode komunikasi Paket Data.

Ini dipilih karena terutama adalah memenuhi persyaratan untuk pengendalian yaitu bisa

berkomunikasi dua arah, handal, selalu online, waktu transfer cepat, serta relatif murah

dibanding yang lain (lihat perbandingan pada Tabel 1).

Skema dari sistem Mobile SCADA yang digunakan untuk penelitian ini adalah

seperti tampak pada Gb.1, dan terdiri dari tiga modul:

1. Front End,

2. Back End,

3. mesin SCADA.

Ketiga modul di atas bisa dilihat pada Gb.6.

Front End

Front End merupakan antar muka pengguna menuju sistem, berupa kumpulan

aplikasi web yang terdiri dari script PHP, yang nantinya akan terpasang di Server

Web/Aplikasi. Pengguna berinteraksi dengan sistem dengan melalui browser web untuk

membuka aplikasi tadi di sebuah PC klien. Dengan kondisi demikian maka sebenarnya

modul ini tidak bisa berkomunikasi secara langsung dengan mesin SCADA. Komunikasi

harus dilakukan melalui Back End. Dengan melalui koneksi langsung ke suatu basis data,

Front End bisa menyediakan pengguna suatu akses terhadap pesan-pesan yang

dikirimkan oleh mesin SCADA melalui Back End. Kebutuhan fungsional yang harus

disediakan pada Front End:

kemampuan mengirimkan pesan ke mesin SCADA,

membaca pesan dari mesin SCADA.

Back End

Back End merupakan sebuah aplikasi Java yang terpasang pada Server

Web/Aplikasi dan berfungsi mengelola koneksi ke mesin SCADA melalui telepon

bergerak. Back End terpasang di server yang sama dengan lokasi Front End. Kebutuhan

fungsional yang harus dimiliki:

kemampuan menginisiasi koneksi ke mesin SCADA via telepon bergerak;

mengelola koneksi ke mesin SCADA, sehingga bila ada data ingin dikirim ke

mesin SCADA, jalurnya menjadi tersedia;

menerima pesan dari mesin SCADA via telepon bergerak dan mengirimnya ke

sistem pengelola pesan (basis data);

menyediakan data umpan balik bagi Front End;

melayani permintaan dari Front End, misalnya untuk mengirim pesan ke mesin

SCADA via telepon bergerak.

Mesin SCADA

Mesin SCADA dibangun dengan suatu micro controller beserta dengan kabel-

kabel serialnya yang menjembatani telepon/modem bergerak dengan obyek kendali.

Yang perlu dipahami pada mesin SCADA ini adalah keharusannya untuk dapat mengirim

dan menerima data melalui Paket Data, yang mana koneksi Paket Data tersebut harus

selalu online. Hal ini bisa terjadi bila telepon klien selalu dalam keadaan men-dial PC

server (lihat Gb.5), dalam artian koneksi terjadi atas inisiatif dari telepon klien, karena

hanya PC server lah yang bisa dihubungi sebab mempunyai alamat IP publik. Sedangkan

telepon bergerak cuma mempunyai alamat IP privat sehingga tidak bisa dihubungi

dengan jaringan GPRS / Paket Data. Dalam kondisi seperti ini maka komunikasi data bisa

terjadi di antara PC dan telepon klien. Kemudian dengan suatu perintah AT+ command

yang merupakan fasilitas pada telepon bergerak maka data-data yang sudah tersimpan

dalam telepon klien tadi bisa dikirimkan ke mesin SCADA, yang pada akhirnya

diterjemahkan oleh mesin SCADA untuk mengendalikan obyek kendali.

Ketiga modul sistem bisa dilihat pada Gb.6. Terlihat bahwa bila seorang

pengguna ingin mengendalikan gerakan mobil-mobilan, maka perintah-perintahnya harus

dilakukan melalui interaksi dengan web yang berupa program aplikasi Front End dalam

PHP. Program PHP ini akan melakukan suatu proses yang mengubah pesan ke format

yang sesuai dan mengirimkan pesan-pesan tadi ke Back End. Setelah itu suatu program

Back End dalam Java (dengan Java Development Kit versi 1.3 atau lebih) memungkinkan

pesan tadi dikirimkan melalui suatu port ke telepon klien via komunikasi Paket Data.

Komunikasi antara pengguna dan obyek kendali

Bila obyek kendali berupa mobil-mobilan maka:

Pengguna memencet tombol di layar yang dimaksudkan untuk ”membelokkan mobil

ke kiri 300 dengan kecepatan 2m/detik”, maka perintah ini ditangkap oleh suatu

proses PHP di Front End yang mengubahnya menjadi karakter ASCII, misalnya

”K30DC2M/D” (artinya belok kiri 300 kecepatan 2m/detik).

Karakter ”K30DC2M/D” ini disimpan dalam basis data dengan skema tertentu

misalnya yang menghasilkan tabel seperti berikut ini:

Tabel motor X

Variabel kendali Arah/Besar Satuan

K 30 D

C 2 M/D

telepon klien

mobil

mesin SCADAkoneksi Paket

Data

koneksi RS-232 dengan AT+ command

Server Web/Aplikasi

Pengguna mengirim pesan lewat browser web

Back End(program Java)

Front End(PHP scripts)

prosesproses

proses

Gb.5. Interaksi antara Modul Front End, Back End, dan Mesin SCADA

Back End dengan aplikasi Java mengambil data dari basis data dan mengirimkannya

melalui port COM teks ASCII ”K30DC2M/D” ke telepon bergerak.

Telepon bergerak tadi dengan perintah AT+ command mengirimkan teks ASCII

”K30DC2M/D” ke mesin SCADA.

Kemudian suatu perintah dilakukan oleh mesin SCADA untuk membaca teks ASCII

tadi pada EEPROM eksternalnya:

read_ext_eeprom(RECV_MESSAGE_LOCATION),

dengan variabel RECV_MESSAGE_LOCATION adalah lokasi disimpannya teks ASCII

pada EEPROM.

Kemudian mesin SCADA mengubah memroses karakter ”K30DC2M/D” menjadi

sinyal-sinyal tegangan yang dikehendaki sehingga mobil-mobilan yang gerakannya

diatur oleh perubahan tegangan bergerak sesuai perintah pengguna.

IV HIPOTESIS

Dengan dibuatnya sistem Mobile SCADA dengan media komunikasi Paket Data

CDMA, dengan sistem mempunyai protokol atau aturan-aturan kendali yang dibangun

berdasarkan perangkat keras dan perangkat lunak yang banyak tersedia di Indonesia,

maka akan didapatkan sebuah sistem SCADA yang bersifat generik, mudah digunakan,

mudah dirawat, mudah beradaptasi, dan mobile, yang sangat bermanfaat bagi industri

menengah ke bawah di Indonesia. Hal ini bisa dicapai dengan membagi-bagi sistem

Mobile SCADA ke dalam tiga modul, yaitu Front End, Back End, dan mesin SCADA,

yang akan menghasilkan suatu sistem yang memisahkan pengembangan fungsional dan

layanan ke dalam dunia komputasi umum dan dunia alat kendali.

V CARA PENELITIAN

5.1 Materi yang dipakai

Materi yang dipakai dalam penelitian ini adalah:

Kartu mesin SCADA, yang tersedia di pasaran Indonesia;

Pemrogram PIC;

Kabel printer DB-25 yang digunakan untuk menyambungkan komputer ke

Pemrogram PIC;

Telepon atau modem bergerak berfasilitas Paket Data dengan kartu teleponnya;

Sebuah komputer yang terhubung Internet dan mempunyai alamat IP publik, serta

terpasang beberapa perangkat lunak baik untuk pengembangan atau produksi.

Berikut ini adalah tabel dari perangkat lunak yang dipasang di komputer beserta

keterangannya:

Tabel 2. Perangkat lunak yang terpasang di komputer beserta keterangannya.

Perangkat lunak Fungsi Keterangan

 Web server produksi   Untuk menjalankan script CGI.

 PHP produksi  Untuk menjalankan Front End yang ditulis

dalam script PHP.

 Compiler Java pengembangan  Java Development Kit (JDK) 1.3 digunakan

untuk meng-compile aplikasi Back End.

 Java run time produksi  Java Runtime Environment (JRE) 1.3 untuk

menjalankan aplikasi Back End.

C cross

compiler

produksi  Untuk menuliskan dan meng-compile source

code pada PC untuk cip PIC.

 Pemrogram

PIC

pengembangan  Untuk memrogram PIC dengan menggunakan

papan pemrogram PIC.

Terminal

software

pengembangan  Sebagai antar muka ke port COM.

5.2 Jalan Penelitian

Sebelum kita mempelajari sistem SCADA yang merupakan produk akhir dari

penelitian ini, akan dipelajari berbagai metode komunikasi bergerak. Variabel yang

dipelajari menyangkut biaya per pengiriman data, waktu terkirimnya data, dan

ketergantungannya pada penyedia komunikasi bergerak. Selain itu akan dipelajari tunda

waktu dan BER (Bit Error Rate) yang muncul pada komunikasi bergerak yang

digunakan.

Setelah itu penelitian dilanjutkan dengan perancangan modul-modul sistem yang

akan dilakukan secara urut dimulai dari pemahaman terhadap obyek kendali terlebih

dahulu yaitu beberapa motor industri sederhana dan dianalisis kebutuhannya. Kemudian

akan dipelajari cara memanfaatkan mesin SCADA agar bisa mengendalikan obyek

kendali.

Selanjutnya kita pelajari komunikasi antar obyek kendali ↔ Back End,

komunikasi Back End ↔ mesin SCADA, komunikasi Front End ↔ Back End, dan

komunikasi pengguna ↔ Front End.

Dari hasil pemahaman terhadap komunikasi di antara ketiga modul maka akan

kita buat protokol-protokol komunikasi, dan akan kita analisa penerapan sistem SCADA

ini dengan metode komunikasi Paket Data.

5.3 Analisis Hasil

Analisis pertama yang dilakukan adalah dengan membandingkan sistem Mobile

SCADA yang dikembangkan dengan sistem-sistem sejenis lainnya yang telah terlebih

dulu dikembangkan oleh Mayer dan lain-lain. Item-item yang dibandingkan yaitu apakah

pada sistem tersebut cocok digunakan oleh industri skala menengah ke bawah di

Indonesia meliputi:

1. mudah digunakan,

2. pengguna tidak harus terlalu memahami cara kerja perangkat keras dari obyek

kendali,

3. mudah dirawat,

4. mudah beradaptasi.

Karena sifat analisisnya yang kualitatif maka akan memerlukan studi lapangan dengan

metode survey.

Selain analisis seperti tersebut di atas, juga dilakukan analisis yang lebih

kuantitatif yaitu terhadap beberapa variabel meliputi waktu respon obyek kendali, biaya

komunikasi data, serta kehandalan sistem.

VI JADUAL PENELITIAN

Tabel 3. Jadual penelitian tahun pertama (2004/2005)

Tahap kegiatanBulan ke:

9 10 11 12 1 2 3 4 5 6 7 8

Persiapan penelitian:

a. Studi literatur

b. Pengadaan bahan & peralatan

c. Dokumentasi

Penelitian komunikasi mesin

SCADA ↔ obyek kendali:

a. Analisis kebutuhan

b. Perancangan protocol

c. Pembuatan perangkat lunak

d. Pengujian perangkat lunak

e. Dokumentasi

Tabel 4. Jadual penelitian tahun kedua (2005/2006)

Tahap kegiatanBulan ke:

9 10 11 12 1 2 3 4 5 6 7 8

Persiapan komunikasi Back End

↔ mesin SCADA:

a. Analisis kebutuhan

b. Perancangan protocol

c. Pembuatan perangkat lunak

d. Pengujian perangkat lunak

e. Dokumentasi

Penelitian komunikasi

Front End ↔ Back End:

a. Analisis kebutuhan

b. Perancangan protocol

c. Pembuatan perangkat lunak

d. Pengujian perangkat lunak

e. Dokumentasi

Tabel 5. Jadual penelitian tahun ketiga (2006/2007)

Tahap kegiatanBulan ke:

9 10 11 12 1 2 3 4 5 6 7 8

Penggabungan modul -> sistem:

a. Pembuatan sistem

b. Pengujian sistem

c. Dokumentasi

Penyelesain:

a. Penyusunan disertasi

b. Presentasi disertasi

c. Perbaikan disertasi

DAFTAR PUSTAKA

1. May dan Donald, L., Mobile’s SCADA systems reduce operating costs,

http://static.highbeam.com/p/publicworks/august011997/

mobilesscadasystemsreduceoperatingcostsalabamasupe/, HighBeam Research, Public

Works, 1 Agustus 1997.

2. Mayer, K. dan Taylor, K., An Embedded Device Utilising GPRS for Communications;

International Conference On Information Technology and Applications , Bathurst,

Australia, 25-28 November 2002.

3. Robotics and Automation Group, Telerobot, Department of Mechanical and

Materials of Engineering, The University of Western Australia, Nedlands 6907,

Western Australia, http://telerobot.mech.uwa.edu.au/, 2004.

4. Tan, L. and Taylor, K., Mobile SCADA with Thin Clients - A Web Demonstration;

International Conference On Information Technology and Applications , Bathurst,

Australia, 25-28 November 2002.

5. Taylor, K., XML and Mobile Computing; Active Server Developers Journal, Elementk

Journals, Februari 2001.

6. Taylor, K. dan Mayer, K., TinyDB by Remote, World Conference on Integrated

Design and Process Technology , Austin, Texas, 3-6 December 2003.

7. Taylor, K. dan Palmer, D., Applying Enterprise Architectures and Technology To The

Embedded Devices Domain; Workshop on Wearable, Invisible, Context-Aware,

Ambient, Pervasive and Ubiquitous Computing, Adelaide, Australia, Conferences in

Research and Practice in Information Technology, Vol. 21, Februari 2003.

DAFTAR RIWAYAT HIDUP

Nama lengkap : Teguh Bharata Adji, ST, MT, M.Eng.

Tempat, tanggal lahir : Yogyakarta, 20

September 1969.

Pangkat/jabatan : Penata Muda / Asisten Ahli.

Riwayat pendidikan tinggi:

Sarjana Teknik pada Jurusan Teknik Elektro Fakultas Teknik Universitas Gadjah

Mada, Indonesia, 1988-1995

Master Teknik pada Jurusan Teknik Elektro Fakultas Teknik Universitas Gadjah

Mada, Indonesia, 1996-1998

Master Engineering pada Department of Electrical Engineering Faculty of

Engineering Doshisha University, Kyoto, Japan, 1999-2001

Karya ilmiah:

“Some Criteria for Formal Complete Integrability of Nonlinear Evolution

Equations”, prosiding internasional pada International Conference on

Mathematics and Its Applications, Gadjah Mada University, Yogyakarta, 14 – 17

July, 2003.

“Arsitektur Jaringan Neural berbasis Simpul RAM untuk Pengenalan Huruf”,

Media Teknik ISSN 0216-3012, Yogyakarta, 1997.

“Computer Program Software for Determining Formal Symmetry of Evolution

Equations”, Media Teknik ISSN 0216-3012, Yogyakarta, No. 1 Th. XXV Edisi

Februari 2003.

“Dukungan XML pada Pengembangan Perangkat Lunak untuk Sistem

Pembelajaran Jarak Jauh di MTI UGM”, Media Elektro ISSN 1411-4968,

Yogyakarta, vol. 13 No. 1 September 2003.

Pertemuan ilmiah yang dihadiri:

Workshop Teknologi Informasi “A Short Course on Developing IT-Enhanced

Engineering Courseware”, Chulalongkorn University, Bangkok, Thailand,

February 10-13, 2003.

Intranet Application System Development Course, Tokyo, Japan, September –

November 2003

Penghargaan ilmiah:

CICC (Center of International Cooperation for Computerization) Certification,

Tokyo, Japan, November 2003

SCADA Last modified: Wednesday, May 30, 2007 

Acronym for supervisory control and data acquisition, a computer system for gathering and analyzing real time data. 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. 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 were first used in the 1960s.

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SCADA (supervisory control and data acquisition) is an industrial measurement and control system consisting of a central host or master (usually called a master station, master terminal unit or MTU); one or more field data gathering and control units or remotes (usually called remote stations, remote terminal units, or RTU's); and a collection of standard and/or custom software used to monitor and control remotely located field data elements. Contemporary SCADA systems exhibit predominantly open-loop control characteristics and utilize predominantly long distance communications, although some elements of closed-loop control and/or short distance communications may also be present.

Systems similar to SCADA systems are routinely seen in factories, treatment plants etc. These are often referred to as Distributed Control Systems (DCS). They have similar functions to SCADA systems, but the field data gathering or control units are usually located within a more confined area. Communications may be via a local area network (LAN), and will normally be reliable and high speed. A DCS system usually employs significant amounts of closed loop control.

SCADA systems on the other hand generally cover larger geographic areas, and rely on a variety of communications systems that are normally less reliable than a LAN. Closed loop control in this situation is less desirable.

This page is intended to help guide you from the basic theory of SCADA systems, to the design of simple SCADA systems, through the selection of vendor hardware and system architecture. Please explore the links and topics below to gain a more complete understanding of this interesting subject!

SCADAProducts for SCADA Automated Monitoring and Control

Campbell Scientific SCADA systems consist of a supervisory computer running HMI (Human-Machine Interface) software and control units performing data acquisition and control functions. The control units make measurements as well as report back to and execute commands from the supervisory computer. The versatility and reliability of our control units set our systems apart from others. These units provide many benefits that PLCs do not.

SCADA System Benefits

1. Control units function as PLCs, RTUs, or DCUs.

2. Control units perform advanced measurement and control independent of the central computer.

3. PID control continues, even if communications to the main computer are lost. 4. Control units have many channel types to measure most available sensors. 5. Systems are compatible with our own or other vendors' HMI software packages. 6. Control units have their own UPS; during ac power loss, they continue to measure and

store time-stamped data. 7. Control units provide on-board statistical and mathematical processing. 8. Systems are easily expandable: add new sites or add sensors to existing sites. 9. Control units have wide operating temperature ranges and operate in rugged

environments.

SCADA Control UnitsOur control units, the CR510, CR10X, CR800, CR850, CR1000, CR3000, or CR5000 function as PLCs (Programmable Logic Controllers), RTUs (Remote Terminal Units), or DCUs (Distributed Control Units). These control units can be linked using ethernet (10 or 100 MB Tlink) or other communications options. Because they have their own operating systems, our control units can be programmed, without ladder logic, to perform advanced measurement and control functions. This eliminates the need for the supervisory computer to do the minute-by-minute control and data acquisition and means that PID control continues, even if communications to the supervisory computer are lost. The control units also provide on-board statistical and mathematical capabilities for data reduction at the remote site and can store up to 2 million time-stamped data points, depending on the model used.

Another major advantage of our systems is that they are easily equipped with an Uninterruptible Power Source (UPS), typically rechargeable batteries and/or solar panels. During power loss, they continue to measure and store time-stamped data, which can be later transmitted to the supervisory computer.

SCADA SensorsAlmost any sensor may be used with the measurement and control system, allowing customization for each operation. Each of our control units features a variety of channel types for flexibility in measuring many different types of sensors. For example, magnetic flowmeters can be measured using pulse counting channels instead of being measured as a 4-20 mA signal. Likewise, ultrasonic level transmitters can be measured using SDI-12 protocol on digital ports instead of as a 4-20 mA signal. Our control units also provide extensive signal conditioning and are easily expandable.

SCADA CommunicationsOur control units support multiple communications options, including: ethernet, radio, telephone, cellphone, voice synthesized phone, and satellite. They also feature peer-to-peer event and polled communication, and can call out to a computer, telephone numbers and/or pagers. Remote lift stations, reservoirs, and pumping stations transmit data via dial up leased phone lines, cell phone, radio, or wide area network T1 links.

SCADA Software

The supervisory computer consists of a PC running either Campbell Scientific's HMI software or another vendor's software. InTouch, Intellution, Lookout, and other software packages can be used in conjunction with our OPC client/server software application. Like other HMI software packages, our software provides a graphical interface that the operator uses to view the status of remote sites, acknowledge alarms, and control the units.

SCADA Example Application

Sedimentation Tank Monitor on/off status of pumpsControl coliform, TSS, and on/off status of pumps

Clarifier Monitor torqueControl on/off status and torque alarms

Generator Monitor and control temperatures and flow rates within exhaust heat recovery unit and heat exchanger

Trickling Filter

Monitor on/off status of pumps and blowers, dissolved oxygen, flow rate, and wetwell level

Control on/off status of pumps and blowers

Chlorine Contact Tank Monitor ORP Control Cl2and SO2 injection

Digester Monitor and control temperature

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Several initiatives to help secure the control systems will be rolled out by the government and federally-funded organizations in the next year, Andy Purdy, acting director of the National Cyber Security Division (NCSD) at the U.S. Department of Homeland Security, told members of the House of Representatives' Subcommittee on Economic Security, Infrastructure Protection, and Cybersecurity during a hearing last week.

"The exposure of these systems to malicious actors in cyberspace is greater than in the past, because these systems are more often connected to the Internet," Purdy said in an interview with SecurityFocus. "With the profit margins of many of the owners and operators, it is a challenge to convince them to spend to reduce the risk."

The DHS has become increasingly concerned over the lack of security of such control networks--amongst which the best known is the supervisory control and data acquisition (SCADA) system--because the lion's share of such control systems are owned by private companies and are increasingly being interconnected to improve efficiency.

Because SCADA and other types of control systems regulate real world activity, such as the amount of water flowing though a dam or the electricity flowing through a transformer, their lack of security has worried experts for some time. Yet, in the past

few years, attacks by external sources, such as online attackers, have jumped to 70 percent of incidents involving SCADA systems, up from 31 percent of incidents recorded between 1980 and 2001, according to a paper published by the British Columbia Institute of Technology.

Sources interviewed for this article maintained that there have been SCADA system attacks, but such incidents are almost never made public. Perhaps the most well-known public incident is that of an information-technology contractor who used his knowledge of control systems to release a million liters of sewage into a river basin in Australia. And U.S. authorities investigated online reconnaissance of U.S. critical infrastructure systems by attackers thought to be linked to al Qaeda in Pakistan, Saudia Arabia and Indonesia.

However, other breaches have happened and the industry has paid the price for secrecy, said Lori Dustin, vice president of marketing and services for control system maker Verano.

"The cost of these breaches is huge--in the millions of dollars," Dustin said. "But the industry will not talk about it, unless the utility makes it public and that will not happen."

The electric power industry is perhaps the most obvious target, because the electric utilities are major users of sensor and control networks. Nearly 1,700 of the 3,200 power utilities have some sort of SCADA system in place, according to a recent survey by industry researcher Newton-Evans. Almost a quarter of companies with SCADA systems did not have a firewall separating the control network from the corporate network, leaving the systems open to attack from the Internet. In addition, only 40 percent of power utilities with such networks bothered to keep detailed access and network-data logs, according to Newton-Evans.

"Is this enough? I have to side with the government officials who tell us that we are not yet secure enough to thwart significant cyber attacks on our energy infrastructure," said Chuck Newton, president of the Ellicott City, Maryland, research firm.

The older networks of control systems have not adapted well to the needs of a deregulated power industry, Samuel Varnado, director of the Information Operations Center at Sandia National Labs stated in written testimony to the Congressional subcommittee.

"Under restructuring, the grid is now being operated in a way for which it was never designed," Varnado said. "More access to control systems is being granted to more users, the demand for real-time control has increased system complexity, and business and control systems are interconnected."

Sandia has demonstrated a way to use SCADA system vulnerabilities to turn out the lights in most major cities, Varnado told the subcommittee last week.

With an aim toward improving the situation, the NCSD has established a clearinghouse for information about control systems security and vulnerabilities under the U.S. Computer Emergency Readiness Team (US-CERT) and Idaho National Laboratory (INL). Known as the Control Systems Security Center (CSSC), the group

aims to reduce the risk of cyberattack on control systems through assessments, educations and incident support, the DHS's Purdy said.

In 2006, the DHS plans on releasing a document outlining the best practices for control-system operators through the Cybersecurity Protection Framework. Also next year, the U.S. agency will determine if a third-party academic institute is needed to act as a central hub for reporting vulnerabilities and incidents, Purdy said.

"If we have a picture of failures in more than one place, we can connect the dots and figure out there is an attack going on," Purdy said.

Legislators have also taken a hand. The latest energy bill passed in August has a provision requiring that the U.S. Department of Energy create an electric reliability organization. The frontrunner for the job is the North American Electric Reliability Council (NERC), which has already created a set of documents on critical infrastructure protection, known as CIP-002 through CIP-009.

The government could give NERC the ability to levy penalties against companies that do not comply with the standards, essentially creating regulations similar to the Sarbanes-Oxley rules that have cause corporations to spend more on security, said Richard Lord, CEO of security consulting and analysis firm The Steadfast Group.

The lack of reports of security incidents has made such legislative efforts necessary, Lord said.

"People have the same attitude--they have not heard about anything going on, so they are not worrying about it," Lord said. "They can't get a budget for it, so why even try to tackle it, is the thinking."

Fixing the problem will not be easy. SCADA systems are expensive to upgrade or to replace, which results in a large number of legacy systems that can be up to 20 years old, William Rush, a physicist for the Gas Technology Institute said in his written testimony to the subcommitte.

"Because many of these systems were designed before critical infrastructure security was a major concern, they often have significant vulnerabilities to unauthorized electronic operations," Rush said in his testimony. "The question confronting the skilled cyberattacker is less 'Can we enter the system?' and more 'How long will it take us to penetrate it?'"

The American Gas Association (AGA) has sponsored a standard for protecting SCADA systems from attack using encrypted communications. Despite the need for additional work, funding problems and industry resistance has slowed the progress of the AGA standard, Rush said.

Asking companies to make extensive changes is unlikely to get industry support, said William Sanders, a professor of electrical and computer engineering at the University of Illinois at Urbana-Champaign and the director of the Information Trust Institute. Sanders and researchers at three other major U.S. universities received a $7.5 million grant from the National Science Foundation in August to pursue ways of securing the power grid from cyberattack.

Proposed solutions need to allow companies to make small steps to secure their systems today, with more in-depth proposals for the long term, Sanders said.

"If we think too far out, saying that you have to completely redesign the infrastructure of the grid, then it is going to be hard to have those companies come on board," he said. "I think the answer is to look for small changes in the short term to better security and to design in security for the long term."

With all the initiatives and the legislative pressure, the owners of critical infrastructure are starting to take the issue much more seriously, said Verano's Dustin.

"The problem is on people's radar now, where it wasn't before," she said.