Foreword

ISO/PDTS 10303-1085 was prepared by Technical Committee ISO/TC 184, Industrial automation systems and integration, Subcommittee SC4, Industrial data.

This International Standard is organized as a series of parts, each published separately. The parts of ISO 10303 fall into one of the following series: description methods, integrated resources, application interpreted constructs, application modules, application protocols, abstract test suites, implementation methods, and conformance testing. The series are described in ISO 10303-1. A complete list of parts of ISO 10303 is available from the Internet:

http://www.nist.gov/sc4/editing/step/titles/.

Annexes A and B form an integral part of this part of ISO 10303. Annexes, C, D, E, aand F are for information only.

Introduction

This application module specifies the use of mathematical values (within a mathematical space) to identify properties (within a property space).

NOTE - This module provides the generalisation of 'representation context' necessary for use of the Mathematical Representation Schema in ISO 10303-50.

EXAMPLE - The temperatures are identified by the mathematical space of numbers x Î R, where x ³ -273.15.

The mapping between this mathematical space and temperatures that is defined by ISO is called Kelvin.

EXAMPLE - The stress tensors are identified by the mathematical space of symmetric 3´3 matrices.

The mapping between this mathematical space and stress tensors is derived from:

• the mapping between real numbers and uni-axial stress that is defined by ISO and called Pascal; and
• the mapping between real vectors and orientation that is defined by 'my coordinate system'.

A property space can be any measurable quantity, such as time, positions within a geometric space, temperature, density, or mass.

NOTE - The mapping between positions within a geometric space and the space of real triples can be a simple Cartesian mapping in metres. There are alternative mappings such as (latitude, longitude and height above MLWS (Mean Low Water Spring tides)) in fathoms and feet.

EXAMPLE - The geometric space in which my aeroplane is at rest is a property space. The geometric space in which the earth is at rest is a different property space.

Industrial automation systems and integration —
Product data representation and exchange —
Part 1085: Application module: Property identification

1 Scope

This application module defines the way in which numbers are used to identify property values.

The following are within the scope of this application module:

• the unit of measure used to identify a property value;

  EXAMPLE - The unit of measure Kelvin is a mapping between the space of temperatures and the space of real numbers.

• the coordinate system used to identify a property value;

• the encoding rule used to identify a property value;

  EXAMPLE - A strain can be represented by an array of 6 numbers using the mathematical or the engineering convention.

  EXAMPLE - A direction can be represented by a normalised array of 3 numbers which are its direction cosines, or by two Euler angles.

• the specification of the identification method for a compound property spaces such as (pressure, temperature, density) or (position, temperature), with respect to the identification methods for the individual component property spaces.

The following are not within the scope of this application module:

• the definition of the property that is identified;
• the definition of the mathematical value makes the identification.