scope:

This part of IEC 61804 is applicable to function blocks (FB) for process control.

This document specifies FB by using the result of a harmonization work as regards several elements.

a) The device model which defines the components of an IEC 61804-2 conformant device.

b) Conceptual specifications of FBs for measurement, actuation and processing. This includes general rules for the essential features to support control, whilst avoiding details which stop innovation as well as specialization for different industrial sectors.

c) The electronic device description (EDD) technology, which enables the integration of real product details using the tools of the engineering life cycle.

The standardization work for FB was carried out by harmonizing the description of concepts of existing technologies. It results in an abstract level that allowed the definition of the common features in a unique way. This abstract vision is called here the "conceptual FB specification" and is mapped to specific communication systems and their accompanying definitions by the industrial groups.

NOTE This document can be mapped to ISO 15745-1.

There are solutions on the market today, which fulfil the requirements of this document and show how the conceptual specification is implemented in a given technology. New technologies will need to find equivalent solutions (see Figure 4).