USERS_GUIDE_TO_MODELS_IN_ATP_ACKNOWLEDGM

USERS GUIDE 
TO 
MODELS IN ATP 
 
 
 
April 1996 
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USERS GUIDE TO MODELS IN ATP 
ACKNOWLEDGMENTS 
The writing of this manual would not have been possible without the participation 
of the many users of MODELS who, over the years, have contributed suggestions 
and prompted discussions on many aspects of the language and its use in ATP. 
These people certainly deserve a large share of the credit for the work that has 
been done. 
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USERS GUIDE TO MODELS IN ATP 
PREFACE 
This Users Guide has been written with the purpose of introducing the MODELS 
language for use with ATP. It is written mostly in a conversational style, as 
opposed to the more formal descriptions found in the MODELS Language Manual 
of the ATP Rule Book. The purpose of this guide is to explain how the MODELS 
language is held together, and to illustrate its usage with discussions and 
examples. 
I realize that a manual like this is never done. There are many aspects to using a 
programming language and to doing simulation. They are best understood 
through one's own experience and glimpses at the experience of others. We can 
continue adding examples to this Guide forever. 
This first version covers the basic aspects of using the MODELS language. The 
main features of the language are discussed in detail and illustrated with 
examples. The interface between MODELS and ATP is also discussed at length. 
What is not included are detailed examples of electrical and control components, 
descriptions which, in my opinion, are beyond the scope of this introduction. The 
objective of this manual is to explain the "how" and the "why" of using MODELS. 
The "what" of the applications belongs to one or more separate tutorials covering 
those subjects, for the application specialists to provide. 
As it is true for any tool, how much a program is used depends to a large extent 
on how much its features are understood. With the usual time pressure of our 
work, of course we wish to be able to use something like this instantly. Having the 
time to play with a new tool is a luxury we can't always afford. But one has to 
realize that any product that took a few years to prepare needs at least a few 
hours of exposure to it to get the whole picture. I hope that the time looking at this 
manual will be time well spent. 
 
Laurent Dubé, April 1996. 
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USERS GUIDE TO MODELS IN ATP 
OUTLINE 
Acknowledgments 
Preface 
Outline 
Contents 
Introduction 
1. Basic aspects of the MODELS language 
2. Writing a model 
3. Writing expressions 
4. Specifying simulation directives 
5. Using a model 
6. Using MODELS in ATP 
7. Libraries of models and functions 
Appendix A – Syntax of the MODELS language 
Appendix B – Keywords of the MODELS language 
Appendix C – Pre-defined constants and variables 
Appendix D – Pre-defined functions 
Bibliography 
Index 
In closing ... 
 
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USERS GUIDE TO MODELS IN ATP 
CONTENTS 
Acknowledgments ..................................................................................................i 
Preface.................................................................................................................. ii 
Outline.................................................................................................................. iii 
Contents............................................................................................................... iv 
Introduction ...........................................................................................................1 
1. Basic aspects of the MODELS language .........................................................2 
1.1. Why use MODELS....................................................................................2 
1.1.1. MODELS in ATP................................................................................2 
1.1.2. Starting to use MODELS ...................................................................2 
1.1.3. Overall form .......................................................................................3 
1.1.4. Similar to a programming language ...................................................3 
1.1.5. What's particular to MODELS ............................................................4 
1.1.6. What about TACS?............................................................................5 
1.1.7. Reasons for using MODELS in a project ...........................................6 
1.2. Value-holding elements, and values .........................................................6 
1.2.1. Kinds of value-holding elements ........................................................6 
1.2.2. Scalars and arrays.............................................................................7 
1.2.3. Use of arrays .....................................................................................8 
1.2.4. Representation of numbers ...............................................................9 
1.2.5. Limits .................................................................................................9 
1.3. Notation, format, and conventions ............................................................9 
1.3.1. Model, MODELS, and MODEL ..........................................................9 
1.3.2. Equal sign and assignment sign ......................................................10 
1.3.3. Parentheses, brackets, and braces .................................................10 
1.3.4. Blank lines .......................................................................................11 
1.3.5. Names .............................................................................................11 
1.3.6. Delimiters.........................................................................................11 
1.3.7. Comments .......................................................................................12 
1.3.8. Line indentation ...............................................................................12 
2. Writing a model ..............................................................................................13 
2.1. Defining the value-holding elements .......................................................13 
2.1.1. Defining constant elements..............................................................13 
2.1.2. Defining data elements ....................................................................14 
2.1.2.1. Using a data value as an array dimension................................14 
2.1.2.2. Dependent data values.............................................................14 
2.1.3. Defining input elements ...................................................................15 
2.1.4. Defining variable elements...............................................................16 
2.1.5. Defining output elements .................................................................17 
2.2. Defining the submodels...........................................................................17 
2.2.1. Locally-defined submodels ..............................................................18 
2.2.2. Foreign submodels ..........................................................................19 
2.2.3. External submodels .........................................................................21 
2.3. Defining the functions..............................................................................23 
2.3.1. Statement functions .........................................................................23 
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USERS GUIDE TO MODELS IN ATP 
2.3.2. Pointlist functions.............................................................................24 
2.3.2.1. External point list ......................................................................25 
2.3.3. Foreign functions .............................................................................26 
2.4. Writing the procedures............................................................................28