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
the Industrial Automation
Insider -- UK's only independent subscription newsletter providing industrial
measurement and control systems users and suppliers with a monthly update on the continuing
evolution and convergence of systems technologies.
Automation Solutions -- Specialists in
SCADA; offer system integration services and custom software development.
Colter Group -- a
UK-based group specializing in selection and installation of SCADA systems and custom
software. Lots of interesting information on their site about the various software and
MiDaTek International -- SCADA
software drivers for Omron, Idec Izumi, Allen Bradley, Koyo, Siemens, Mitsubishi,
Dupline Optolink controllers, BitLink, and FastLink ISA card.