scope:

Scope and object

International Standard IEC 61162-420 specifies the requirement for and basic components of the IEC 61162-4 series companion standards. These components are referred to as follows:

a) PCS (PISCES companion standards) which contain the rules for creation of companion standards. The general principles underlying the PCS are described in clause 4.

b) PCSDL (PCS description language). Part of the PCS is the definition of the syntax for the various types of companion standard documents that make them readable by computer tools. The PCSDL is described in clause 5.

c) function block description. The function block description is a high level and graphical description of applications using the IEC 61162-4 series interface standard. The function block syntax is specified in clause 7.

d) PFS (PISCES foundation specifications) which contain a framework for classification of applications adhering to the IEC 61162-4 standard. The PFS will also provide a minimum level of interoperability between different manufacturers' applications using this framework. The PFS is described in clause 6.

Clause 5 contains the complete reference to the PCS description language. Subclause 5.2 explains the basic concept of the PCS which is given by the distinction between four types of specifications: applications, interfaces, information and data types. General conventions with respect to the syntax of the PCS can be found in 5.3. All PCS documents are based on a similar structure. This approach is intended to make it easier to become familiar with the syntax and semantics of the PCS which is defined in 5.3.1. The four subclauses thereafter explain in detail the syntax and semantics of the four different types of specifications generated by the PCS.

Clause 6 describes the relationship between the different classes of IEC 61162-4 applications and gives an overview of their functionality. The annexes contain the detailed PCS definitions for the classes.

The objective of companion standards is to provide definitions of the information that is transferred within an integrated ship control system and of how these information items can be accessed or provided. Furthermore, the standard shall allow the definition of the actual network interfaces which the applications use to connect to the system. The description format is machine-readable, allowing an automatic compilation of the description into interface software.

A companion standard allows the reader to, at will, shift the focus between a technical specification and a definition of interfaces and information items. The development team can determine information attributes like unit, power, accuracy and the structure of the system architecture and create a common interpretation basis for data before the system implementation. The formalisms underlying the specification language will at the same time provide an unambiguous and precise description of the equipment interfaces which allow the use of computer tools to automatically generate interface program codes or to inspect and manipulate interfaces on-line, for example for debugging and monitoring purposes.