Page 275 - Electric Drives and Electromechanical Systems

272 Electric Drives and Electromechanical Systems

pervasive connectivity of sensors will be a disruptive influence on traditional
manufacturing processes.
As discussed previously, the major components of an industrial control system can
include all or some the following (i) Programmable logic controller (PLC), that controls
the logical operation of the system together with providing a range of other functions;
(ii) Distributed control systems (DCSs), the distributed controllers control individual
aspects of the processes, for example a drive’s speed, and can remain operational even if
part of the overall control system fails, allowing limited operation during maintenance or
undesired events, and (iii) a Supervisory Control and Data Acquisition (SCADA) systems,
used to monitor and control industrial processes by gathering data in real time from
remote locations, allowing fully informed supervisory decisions to be made prior to
adjust any control parameter (McLaughlin et al., 2016).
Several significant challenges are concerned with the introduction of these systems
into the overall enterprise-based computing structure and its managements and
security. These aspects are discussed after considering the technologies involved.
Following a brief review of hard-wired networking approaches and Supervisory Control
and Data Acquisition systems, a review of more recent trends is undertaken, from the
Industrial Internet of Things to Cloud Manufacturing.

11.1 Conventional networks

The information technology revolution in automation technology has opened up a wide
range of savings potentials in the optimisation of system processes and makes an
important contribution towards improved use of resources. Industrial communication
systems have assumed a key function in this respect: it should be recognised that
networking goes beyond the interfacing of factory systems, to interface with design and
documentation systems to form virtual organisation and other related systems.
Initially fieldbus systems were developed by industrial systems vendors, leading to several
proprietary standards. With the introduction of the Internet, communications first
migrated to ethernet and related standards and then to wireless technology. It should be
noted that with the legacy issues typically found within manufacturing equipment, where
a conservative design approach to safety critical system and security issues is present, the
move to more recent communication technologies has not been as rapid as in other
application domains (Wollschlaeger et al., 2017).
The actual selection of the industrial networking technology is based on several
criteria, including:

The detailed requirements of the application.
The capabilities of the network technologies, including speed and timing
requirements.
Integration with existing equipment.
Availability of components.
Costs of installation, devices, training, and maintenance.