wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

13-2 Industrial Communication Systems
attempts to today’s situation. A section is devoted to the network interconnection problem that is a
cornerstone for integration. The application view of vertical integration will be briefly sketched, and the
question of how to achieve security will be discussed. Finally, a few trends of the ongoing evolution will
be highlighted.
13.2 Historical Background
Historically speaking, the idea of achieving a data flow from the shop floor and the field level to the
office level together with proper network integration is not new. What is new is the current focus on
Internet technologies as upper level of the interconnection. However, the integration idea itself was
already part of the computer-integrated manufacturing (CIM) concept suggested in the 1970s [H73].
The approach put forward then was to create a transparent, multilevel network to structure the information
flow required for factory and process automation [DSP88]. To cope with the expected complexity,
a strict subdivision of the information processing into a hierarchical model was devised that became
to be known as the automation pyramid. The model exists in various versions with different naming
conventions and numbers of levels, but it typically comprises four to six functional levels as depicted
in Figure 13.1. Along with the definitions of functionalities—which of course varied according to the
application domain—networks were associated to the individual levels. Originally, different networks
were intended for these purposes. In recent years, however, the complexity of the pyramid, i.e., the
number of levels was reduced chiefly because of the consolidation process that took place in the field of
networking technologies. Today, the upper levels are dominated by IP-based networks (mostly on the
basis of Ethernet) and, more generally, technologies from the office domain, whereas the lowest level is
still home to field-level networks in various forms.
A critical review shows that the CIM approach proposed 30 years ago practically flopped. There are
niches where integration became tight and very successful, like in CAD/CAM solutions for tooling
machines or (micro)electronic manufacturing. The comprehensive integration of all levels across all
possible application areas however failed, and still today, the term CIM has a largely negative connotation
in many industries. The reasons for the spectacular failure of a basically good idea are manifold:
The overall concept was overloaded and far too ambitious. In particular, it had been designed
mostly without a view to the feasibility of implementation. In fact, the concepts did not show much
Strategic
planning
Company level
Finance
controlling
Market
ERP
SCM
Marketing
Production level
Development
engineering
Operative and
quality engineering
Ethernet
Ethernet
Supplier
Production control
Shop floor level
Stock Logistics Production Assembly Shipping
Process level
Control
MES SCADA
Transportcontrol
Machine
control
Field level
Cell
control
Packaging
control
Fieldbus/
industrial
ethernet
Fieldbus
FIGURE 13.1 Typical functional units inside a contemporary company and their interrelation with the automation
hierarchy as well as associated network technologies.
© 2011 by Taylor and Francis Group, LLC