What is SCADA
SCADA stands for “Supervisory Control and Data Acquisition”. SCADA
is a type of process control system architecture that uses computers, networked
data communications and graphical Human Machine Interfaces (HMIs) to enable a
high-level process supervisory management and control.
SCADA systems communicate with other devices such as programmable
logic controllers (PLCs) and PID controllers to interact with industrial
process plant and equipment.
SCADA systems can be run virtually, which allows the operator to
keep a track of the entire process from his place or control room. Time can be
saved by using SCADA efficiently. One such excellent example is, SCADA systems
are used extensively in the Oil and Gas sector. Large pipelines will be used to
transfer oil and chemicals inside the manufacturing unit.
SCADA History
- Earlier to the
birth of SCADA systems, manufacturing floors and industrial plants relied
on the manual control and monitor using push buttons and analog equipment.
As the size of the industries and manufacturing units grew in size, they
started using relays and timers, that provided supervisory control to a
certain extent.
- Unfortunately,
relays and timers were able to solve problems only with minimal automation
functionality, and reconfiguring the system was difficult. So, a more
efficient and fully automated system was required by all industries.
- Computers were
developed for industrial control purposes in the early 1950s. Slowly, the
telemetry concept was introduced for virtual communication and
transmission of data.
- Around the year
1970, the term SCADA was coined along with the evolution of
Microprocessors and PLC concepts.
- This helped for
the development of a fully automated system, that can be used remotely in
Industry. As years rolled by, in the early 2000s, distributed SCADA
systems were developed.
- Modern SCADA
systems came into existence that allowed us to control and monitor
real-time data anywhere in the world.
- The real-time
interaction boomed up the business and took the growth of industries to
greater heights. Even if the operator did not have much knowledge of
software development, he was able to manage the modern SCADA systems.
Functions of SCADA Systems
In a nutshell, we can tell the SCADA system is a collection of
hardware and software components that allows the manufacturing units to perform
specific functions. Some of the important functions include
1. To monitor and
gather data in real-time
2. To interact with
field devices and control stations via Human Machine Interface (HMI)
3. To record systems
events into a log file
4. To control
manufacturing process virtually
5. Information Storage
and Reports
The Future Of SCADA
Today, both public and private sector organizations are under
greater pressure to provide increasing quality of service under ever-tightening
budgets. Also, governmental regulations require stricter monitoring, greater
energy efficiencies and detailed reporting. In this challenging environment,
the organization’s supervisory control and data acquisition (SCADA) system
offers new and exciting means to wring additional benefits out of a proven
workhorse.
To understand how such a level of future SCADA sophistication is
possible requires only a simple analysis of our progress to date. Since the
introduction of computerized control systems in the 1960s, five generations of
SCADA evolution can be clearly defined.
Made-to-order SCADA systems were developed For special-purpose
applications such as NASA’s Johnson Space Center launch system in Houston. In
the 1960s, Houston had a problem: The Space Center had a large number of
essential variables to monitor, and there existed no off-the-shelf technology
capable of providing the functionality required.
Legacy SCADA systems are those that continue to be used despite
relatively poor performance and a lack of compatibility with other systems.
Often, replacing hardware components is an expensive, unpalatable option for
the customer. Proprietary SCADA systems tie the customer to one specific
control device manufacturer, creating a difficult negotiating position for the
customer during future purchases.
For these systems, the increased flexibility of new computer hardware and SCADA
software offers an opportunity. While most SCADA software products support
industry-standard control protocols, products such as VTS also support
protocols for proprietary and legacy control products. These disparate systems
can now be integrated into the same centralized management model while allowing
customers the time to develop a plan for migration away from legacy and
proprietary SCADA.
Industry
Trends
Review of SCADA evolution illuminates three important trends:
- The incremental
cost to apply SCADA to additional assets is decreasing
- The amount of data
being gathered is increasing.
- Basic logic and
control is becoming decoupled from the operator, reducing the relative
importance of the HMI component of SCADA software.
For example, a SCADA application installed at Air Products and
Chemicals of Allentown, PA uses Trihedral’s Visual Tag System (VTS) software to
accumulate nationwide realtime data from 6000 tanks. Product usage history is
used to forecast refill date ranges for each tank. The information is
communicated to the organization’s SAP enterprise resource planning system. It
is then summarized to schedule delivery routing to cut down product waste and
make best use of the company’s fleet of $1 million cryogenic gas delivery
trucks. The reduced cost of monitoring these widely dispersed assets made the
application feasible, but at this time the company is still using human-based
decision making to control daily functions.
Such geographically widespread asset management is not limited to
million-dollar assets. As the cost of SCADA continues to decline on a per-asset
basis, low cost assets such as vending machine inventories, department store
inventories, restaurant grease traps, and many other items that could not be
monitored feasibly in the past will become increasingly easier to incorporate
into the SCADA model. One can only imagine a future in which telemetry devices
as small as a grain of sand are used as locating beacons on personal jewellery.
Conclusion
Costs for basic
SCADA components are expected to continue to decline in the future.This trend
will support SCADA use in organizations with assets of lower individual value,
leading to larger, more dispersed SCADA systems.Simultaneously, larger organizations
will take advantage of the growing number of value-priced, wide-area
communications options to interconnect geographically dispersed SCADA and
business systems. SCADA software developers must understand how to leverage new
technological advances in communications without excluding legacy systems.
Low-level SCADA integration will be simplified. The size and complexity of
SCADA will increase at an accelerating rate, requiring the creation of tools
and integration methods that provide fast, error-free replication for common
SCADA tasks. Successful cooperation between vendors will be essential in
providing the maximum benefit to the customer.
Finally, the SCADA system will function more and more as a large control loop,
able to operate autonomously at increasingly higher levels, based on fewer
inputs from operational personnel. Optimization methodologies will be applied
in a myriad of situations, allowing organizations to develop larger SCADA
systems without incurring unreasonable operational costs or significant
staffing increases. As such, the value of the pure HMI component of SCADA
software, as we know it today, will decline relative to the many other emerging
benefits SCADA systems will offer.
References
- NASA (Unknown
date). Johnson Space Center Mission Control, USA Launch System
Specifications, Retrieved October 8, 2009, from
http://www.aerospace-technology.com/ projects/johnsoon/
- NERC (various
dates), CIP Standards, Retrieved October 8, 2009, from http://www
.nerc.com/page.php?cid=2|20
- Water Sector
Coordinating Council Cyber Security Working Group (March, 2008), Roadmap
to Secure Control Systems in the Water Sector, Retrieved October 8, 2009,
from http://www.awwa.org/files/GovtPublic
Affairs/PDF/WaterSecurityRoadmap031908. pdf
- FDA (August,
2008), Guidance for Industry Part 11, Electronic Records; Electronic
Signatures – Scope and Application, Retrieved October 11, 2009, from
http://www.fda.gov/ downloads/RegulatoryInformation/Guid
ances/ucm125125.pdf
