Introduction

The following is a presentation of the different rules of compatibility between types within each of the following families:

• the Elementary Data Type (EDT) family

• the Derived Data Type (DDT) family

• the Generic Data Type (GDT) family

The Elementary Data Type (EDT) Family

The Elementary Data Type (EDT) family contains the following sub-families:

• the binary format data type sub-family

• the BCD format data type sub-family

• the Real format data type sub-family

• the character string format data type sub-family

• the bit string format data type sub-family

There is no compatibility whatsoever between two data types, even if they belong to the same sub-family.

Derived Data Type (DDT) Family

The Derived Data Type (DDT) family contains the following sub-families:

• the table type sub-family

• the structure type sub-family:

  • structures concerning input/output data (IODDT)

  • structures concerning input/output device (Device DDT)

  • structures concerning other data

Rules concerning the structures:

Two structures are compatible if their elements are:

• of the same name

• of the same type

• organized in the same order

There are four types of structure:

Compatibility between the structure types

Rules concerning the tables

Two tables are compatible if:

• their dimensions and the order of their dimensions are identical

• each corresponding dimension is of the same type

There are five types of table:

Compatibility between the table types:

The Generic Data Type (GDT) Family

The Generic Data Type (GDT) family is made up of groups organized hierarchically which contain data types belonging to the following families:

• Elementary Data Types (EDT)

• Derived Data Types (DDT)

Rules:

A conventional data type is compatible with the genetic data types related to it hierarchically.

A generic data type is compatible with the generic data types related to it hierarchically.

Example: