1 INTRODUCTION

The software described in this manual is intended to be used in the ESO VLT project by ESO and authorized external contractors only.

While every precaution has been taken in the development of the software and in the preparation of this documentation, ESO assumes no responsibility for errors or omissions, or for damage resulting from the use of the software or of the information contained herein.

1.1 PURPOSE

This document is the User Manual for the CCS tools to be used for the design and maintenance of the On Line Database for the VLT project.

It is intended to provide all the necessary information to use this software to develop application software running on the workstations and on the LCUs. The document presents also a general overview of the Object Oriented approach that will be used to design VLT databases, provided the loader functionalities.

The method server, described in the previous release of this manual, has been withdrawn.

It will be replaced by guidelines on the development of C++ support classes to implement methods for the access of dbl classes.

The manual assumes that the reader has a good knowledge of UNIX, C language and is familiar with CCS and or LCC Common Software.

In addition to the Introduction section, this manual contains two major sections:

User's Guide, describing the functionality provided by the software, including examples of utilization.

Reference, describing all the tools available and the file formats used to design the database

1.2 RELEASE NOTES

For details on not implemented features, known problems and last minute changes, look at the files RelNotes_xxx.text and ChangeLog in the dbl module's directory.

1.3 SCOPE

Knowledge of CCS and LCC Functional Specification and Design documents is a requirement.

1.4 APPLICABLE DOCUMENTS

The following documents, of the exact issue shown, form a part of this document to the extent specified herein. In the event of conflict between the documents referenced herein and the content of this document, the content of this document shall be considered as a superseding requirement.

[1] VLT-PRO-ESO-10000-0228, 1.0 --- VLT Software Programming Standard

[2] VLT-SPE-ESO-17210-0001, 1.0 --- VLT CCS Functional Specification

[3] VLT-SPE-ESO-17210-0002, 2.2 --- VLT LCU Software Specification

[4] VLT-MAN-ESO-17210-0619, 1.7 --- VLT Central Control Software User Manual

[5] VLT-MAN-SBI-17210-0001, 3.4 --- VLT LCU Common Software User Manual

1.5 REFERENCE DOCUMENTS

[6] B.W.Kernighan D.M.Ritchie - The C programming language, second edition - Prentice Hall, USA, 1988

[8] G.Booch - Object-Oriented Design With Applications - Benjamin Cummings, USA, 1991.

[9] VLT-MAN-ESO-17200-0981, 1.0 15/01/96 --- VLT Software Problem Report Change Request User Manual

[10] VLT-MAN-ESO-17210-0667,1.0 --- VLT Software Guidelines for the Dev. Appl. Soft.

1.6 ABBREVIATIONS AND ACRONYMS

1.7 GLOSSARY

Object Oriented terminology cannot be fully described in this glossary. A good reference book is the Booch's volume[8].

attribute
A data item contained inside a point and used to characterize its status. The RTAP definition of attribute has been extended in order to consider attributes also the sub-points (structured attributes). Using an object oriented terminology, attributes correspond to "data members".

branch
The sub-tree of the hierarchical data base identified by a unique root point. A branch is a logical collection of related points.

class
An abstract description of the properties of a category of objects. Structure (attributes), behaviour (methods), and inheritance (parents, or recursive structure and behaviour) are specified.

inheritance
Inheritance is a relationship between classes where one class is the parent (base/superclass/ancestor/etc.) class of another. The new class gets all the properties of the parent and can change them or add new ones. Inheritance provides programming by extension and can be used as a "kind of" relationship.

method
A method is a function or procedure which is defined in a class and typically can access the internal state of an object of that class to perform some operation. A method implements behaviour, that is how an object acts and reacts.

object
The following is one of the many possible definitions: "an object represents an individual, identifiable item, unit, or entity, either real or abstract, with a well-defined role in the problem domain.". The Booch's volume [8] gives much more details.

Object Oriented
A design methodology based on the concepts of class and object.

overloading
Is the technique of redefining properties in a derived class, thus providing a specialized behaviour.

point
Is the basic unit of the hierarchical database structure. It is normally used to represent a physical entity and thus it is an instance of a class.

sub-class
A class that inherits its properties from another one (the parent-class), overloading some of them and/or adding new ones.

1.8 STYLISTIC CONVENTIONS

bold
in the text, for commands, filenames, pre/suffixes as they have to be typed.

italic
in the text, for parts that have to be substituted with the real content before typing.

<name>
in the examples, for parts that have to be substituted with the real content before typing.

1.9 NAMING CONVENTIONS

This implementation follows the naming conventions outlined in the VLT Programming