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

5
Profiles and
Interoperability
Gerhard Zucker
Vienna University
of Technology
Heinz Frank
Reinhold-Würth-University
5.1 Interoperating Components............................................................ 5-1
5.2 Application of Profiles......................................................................5-4
Function Blocks of IEC 61499. •. Functional Profiles in LON. •. .
Logical Nodes of the IEC 61850
5.3 Achieving Interoperability...............................................................5-6
References...................................................................................................... 5-7
5.1 Interoperating Components
In distributed automation systems, automation devices like sensors, actuators, and controllers are
connected through an industrial communication system (Figure 5.1). Automation systems of the past
were freely configurable, allowing the system to be adapted specifically to one given installation.
Although this could already be done in software (and not by connecting wires directly), it was still
necessary that every system had to be programmed individually, which resulted in a unique and
nonreusable installation. Costs for integrating multiple industries, maintenance, and extensions of
existing systems were considerable and required well-educated experts. When automation systems
became more sophisticated and consisted of a considerable amount of communicating components,
this effort became too high and a new solution had to be found. Instead of programming each component
individually, an existing definition has since been used as a template and reproduced for as many
components (or nodes, as they are called from communication point of view) as needed. The abilities
(i.e., the functions) of each component are standardized, the nodes do not need to be programmed,
they merely need to be configured. These functions can be coupled, thus creating the functionality of
the whole system.
The users do not need to know about the internal design of a node; they only have to know about the
functions that a node offers. Well-known functions are, for example, actuators, sensors, and controllers,
each of which can be offered by a separate node (or all integrated into one complex node). Instead of
knowing the whole component, the user only has to know the interface of the component, that is, the
variables that it offers and their behavior.
When configuring such a system, the user has to connect the outputs of one function block with the
inputs of other function blocks. Physical data transmission does not require dedicated wires, but can
be done on a shared bus, where messages are transported between nodes using distinct addresses for
sender to receiver in the message.
The goal is to get a system that can easily be put into operation, preferably with little (or even no)
commissioning. While the advantages are obvious, one also has to consider how to achieve cooperating
components. This is an issue on multiple layers. While before it was sufficient to check for the correct
physical parameters like voltage before connecting two components by a dedicated wire, we now have
5-1
© 2011 by Taylor and Francis Group, LLC