SCADA stands for
Supervisory Control
And Data
Acquisition. The main goal of SCADA is to monitor, control and alarm plant or regional
operating systems from a central location. While override control is possible, it
is infrequently utilized; however control set points are quite regularly changed
by SCADA.
In a municipal context, "plant"
systems are typically water and wastewater treatment facilities, while
"regional" systems include intake and/or effluent structures, pumping
stations, chlorination stations, control valve stations and the like.
What makes up a SCADA
system?
There are three main elements to a SCADA
system, various RTU's (Remote
Telemetry Units),
communications and an HMI (Human
Machine Interface).
Each
RTU effectively collects information at a site, while communications bring that
information from the various plant or regional RTU sites to a central location,
and occasionally returns instructions to the RTU.
The HMI displays this
information in an easily understood graphics form, archives the data received,
transmits alarms and permits operator control as required.
Communication within a plant will be by data
cable, wire or fiber-optic, while regional systems most commonly utilize radio.
The HMI is essentially a PC system running
powerful graphic and alarm software programs.
Why
is SCADA so popular?
The major attraction of SCADA to a
municipality is the ability to significantly reduce operating labor costs, while
at the same time actually improve plant or regional system performance and
reliability. Information gathering within a plant no longer requires personnel
to spend time wandering all over the site, and correspondingly the frequency of
field site inspections required in a regional system can be minimized.
Costly after-hours alarm call-outs can often
be avoided since a SCADA system will indicate the nature and degree of a
problem, while the ability to remotely control site equipment may permit an
operator at home to postpone a site visit till working hours. SCADA based
alarming is also very reliable since it is in-house and tied directly to process
control.
A significant feature of a SCADA system, often
not fully appreciated, is the trending of data and nothing comes close for speed
and ease of operation. When graphically displayed, accumulated operating data
often will indicate a developing problem, or an area for process improvement.
Reports can easily be generated from this data utilizing other common software
programs.
It should be appreciated that while a SCADA
system is often complex to configure - it is extremely easy to operate!
SCADA stands for
Supervisory Control
And Data
Acquisition. The main goal of SCADA is to monitor, control and alarm plant or regional
operating systems from a central location. While override control is possible, it
is infrequently utilized; however control set points are quite regularly changed
by SCADA.
