Process
Control
From
the transformer to the transducer our electrical installation staff are fully conversant
with industrial and national standards.
LV Switchboards and motor control centres are the focal point of most installations.
From small control panels through to MCC's housed in their own air conditioned control
rooms our electrical engineers can supply all design and installation requirements.
The design service also includes the provision of training programmes and comprehensive
Operation & Maintenance manuals.
Analog and Digital instrumentation are installed to measure and control many process
variables, for instance; flow, level, pressure, and temperature.
The
move towards improvements in plant operation and efficiency has evolved around developing
automatic control systems and automating mechanical and process plant.
PLC and SCADA Process Control Systems
Programmable Logic Controllers (PLC's) have evolved considerably, since first being
introduced into the UK by Modicon in 1970. PLC control is now an accepted part of every
process plant control system.
Supervisory, Control, Automation, and Data Acquisition (SCADA) have similarly evolved and
found favour, with their increased power and capability matching the development of the
PC's, on which they run, during the last decade.
Programming is though in many extents the final output stage of PLC/SCADA design, our
engineers are fully aware of the plant equipment and operational process requirements.
PLC
Microprocessors, industrial electronics, and software are the building blocks of PLC's.
The increase in processing power, the reduction in size and the sophistication, of the
three elements respectively, have produced micro PLC's with the power to handle analogue
signals, carry out PID control and enable Fuzzy Logic control strategies to be developed.
There are a multitude of manufacturers in the market place, the strong competition
continuously driving forward the technology. Including; Allen Bradley, Mitsubishi,
Siemens, Cegelec. Each have their own benefits and restrictions, and quite often their own
programming language, fortunately the adoption of IEC 1131 provides a common framework to
enable a wider understanding of the different manufacturers techniques to occur.
SCADA
Management information is the feedstock of process plant operational decisions. Automation
has provided process plant managers the opportunity to change production cycles and set
performance parameters in time scales that would not have been possible under manual
systems. In order to partition the information and plant management from the production
floor control systems the supervisory control automation and data acquisition packages
have come to the fore.
The majority of today's packages are in monitoring and management environments, however
the power and capability of the PC has grown to such an extent, that, it will be difficult
for the control systems engineers to resist using this incredible processing and
mathematical power in their schemes.
Man Machine Interfaces
Traditional control systems use pushbuttons, selector switches, indicator lights and chart
recorders to provide information on the plant status and to allow operators to set the
plant to work. On the other hand SCADA packages use computers and VDU's to achieve the
same ends. Now a third alternative is available and is quickly gaining acceptance and wide
use, this is the MMI or HMI (Human Machine Interface). Available across a very wide range
from simple alpha-numeric keypads with scrolling text display, through to full graphical
display capability with touch screen operation.
The MMI provides a very cost effective solution and through simple menu based programming
provides a level of information and control that would not be possible with conventional
systems.
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