In this paper; we present minimal examples of models that exhibit unexpected or surprising results; then we explain the general causes of such behaviors and propose to introduce the notion of clock in the language to solve the issues. In contrast to  and ; we focus here on models resulting from the composition of other models: we aim at showing that the current discrete-time theoretical model of Modelica is not robust with respect to model composition. For the final user; it means that it is generally not possible to build reliable models involving discrete-time aspects by simply connecting generic library models: manual adjustments are often required to obtain the expected behavior.
Keywords: Discrete-time modeling; clock calculus
Proceedings of the 8th International Modelica Conference; March 20th-22nd; Technical Univeristy; Dresden; Germany
 R. Nikoukhah; Activation Inheritance in Modelica; EOOLT; 2008
 R. Nikoukhah; S. Furic; Synchronous and Asynchronous Events in Modelica: Proposal for an Improved Hybrid Model; 6th international Modelica conference; 2008
 A. Benveniste; P. Le Guernic; and C. Jacquemot; Programming with events and relations: the Signal language and its semantics; 1991
 S. Bliudze.; D. Krob; Modelling of Complex Systems: Systems as dataflow machines; 2009