Introduction
This book is a practical guide to component-based development of
distributed, embedded, and control systems proposed within the
new IEC 61499 international standard. IEC 61499 defines a
component-based modeling approach using
function blocks.
At first glance, this model appears to be quite different from
the component models of other software engineering approaches
such as COMA, DCOM, or .NET (Sunder et al., 2006). In fact,
however, a function block possesses the required characteristics of
a software component defined as “a unit of composition with
contractually-specified interfaces and explicit context
dependencies only. A software component can be deployed
independently and is subject to composition by third parties.” (C.
Szyperski, 2006). This statement precisely describes a function
block.
In other words, the expression
function block
is broader than
software
block
insofar as a
function block
captures functionality
that can be implemented as software or hardware or a combination
of both. This robust character of the
function block
makes it
appropriate to use in the broader embedded systems domain.
The IEC 61499 Standard for Function Blocks for Industrial
Process Measurement and Control Systems (IPMCS) is the result
of more than 10 years of work within Working Group 6 (TC 65) of
the International Electrotechnical Commission (IEC). Working
Group 6 comprises leading experts in software architectures of
industrial automation systems including as its members the biggest
global vendors of automation products and solutions.
The standard was conceived because an increasing portion of
the intellectual property (IP) related to the domain of industrial
automation is now being expressed in the form of software.
Efficient management of this IP becomes the key factor for
answering the new challenges of markets that require flexibly
reconfigurable production tailored to order. The efficient
management of this IP requires easy integration of components, as
well as their re-configuration and re-use.
The automation software spans across diverse functional
domains, such as control, diagnostics, process rendering, modeling,
human-machine interface, communication, and
so
on. Thus,
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