ESL - A new Continuous System Simulation Language

Abstract

ESL is a new Continuous System Simulation Language (CSSL) which is being developed under contract from the European Space Agency. It is based on the concepts outlined in Refer ence 6. The main features of the new language are: (1) Models can be built from submodels (2) Separation of model and experiment (3) Advanced discontinuity-handling (4) A parallel segment feature. The implementation of ESL requires both an interpreter and a translator version of the language. The interpreter translates the user's program into an intermediate code (H-code) which is then interpreted at run-time. The translator may be used to convert the H-code to FORTRAN-77 to produce a more efficient ex ecutable program of production runs. The entire system (with the exception of a few low-level routines) is being written in FORTRAN-77. A prototype version of the language was installed in August 1983 and is currently undergoing evaluations. Details of this version are given with examples of its use.