LACATRE: The basis for a Real Time Software Engineering Workshop

Zusammenfassung

The development of Real Time Applications raises a number of problems which add themselves to those, already non-trivial, generated by the development of all Information Systems, either during their design or their implementation, mainly because such applications are closely coupled to the physical world with which they interact.

This paper is dedicated to those who have to solve this type of applications using Real Time Executives.

The major difficulties they encounter are:

• the expression of the dynamical aspect of this type of applications

• the number and the variety of these Real Time Executives

  Standardisation efforts, now performed by Real Time Executive constructors in order to promote Real Time Executive standards, can be considered as some sort of answer to the second problem

  In order to take both problems into account and to bring up global answers, we define the LACATRE graphical language (LAngage de Conception d’Applications Temps REel) which allows the modelisation of an application using graphical representations of the main entities present (handled) in commonly used Real Time Executives (i.e. VRTX, RTC, RMX,...)

It may be used in two different ways:

• a free-hand use for design aid and/or graphical documentation of programs in which case it may be considered as a method of design and this is not the subject of this paper

• an interactive tool as a generator of multitask Real Time Application program skeletons. In this aspect, it may form the basis of a Real Time Software Engineering Workshop

Within the Software Lifecycle, LACATRE covers a part of Preliminary Design and Detailed Design. It allows the expression of the dynamic decomposition and task relationships, in order to obtain the skeleton of the multitask program but not a precise description of the computation.