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Introduction and Brief History of SCADA

SCADA (Supervisory Control and Data Acquisition) has been around as long as

there have been control systems. The frst SCADA systems utili!ed data

acquisition by means o" panels o" meters# lights and strip chart recorders.Supervisory control $as e%ercised by the operator manually operating various

control &nobs. These devices $ere and still are used to do supervisory control

and

data acquisition on plants# "actories and po$er generating "acilities.

'... undamental *rinciples o" +odern SCADA Systems

SCADA re"ers to the combination o" telemetry and data acquisition. SCADA

encompasses the collecting o" the in"ormation# trans"erring it bac& to the central

site# carrying out any necessary analysis and control and then displaying that

in"ormation on a number o" operator screens or displays. The required control

actions are then conveyed bac& to the process.

The *,C or *rogrammable ,ogic Controller is still one o" the most $idely used

control systems in industry. As needs gre$ to monitor and control more devices

in

the plant# the *,Cs $ere distributed and the systems became more intelligent

and

smaller in si!e. *,Cs and DCS or (Distributed Control Systems) are used as

sho$n belo$.