Automated Test Generation for Synchronous Controllers

This paper addresses the problem of automating the produc-tion of test sequences for a particular class of ProgrammableLogic Controllers (em4) produced by InnoVista Sensors.The latter are synchronous systems and are programmedby means of an ad hoc integrated development environment(IDE). People using and programming such controllers arenot necessarily experienced programmers, so the develop-ment of software applications must be simple and intuitive.This should also be the case for testing. Until now, the de-sign of test input sequences is informal and testing is interac-tively performed by programmers using a simulator includedin the IDE. Based on previous investigations on testing ofsynchronous programs, we propose a method to automat-ically generate test inputs sequences for synchronous con-trollers. In a previous paper we presented a new test speci-cation language, called SPTL (Synchronous Programs Test-ing Language) that makes possible to simply express testscenarios. In this paper, we present a prototype tool thatwe designed and developed, named "Testium", that trans-lates a SPTL program into a set of constraints exploited bya Prolog solver to randomly choose test inputs.