Specification and Automated Verification of Real-Time Behaviour —A Case Study

In this paper we sketch a method for specification and automaticverification of real-time software properties. The method combinesthe IEC 848 norm and the recent specification techniques TCCS (TimedCalculus of Communicating Systems) and TML (Timed Modal Logic) - supported by an automatic verification tool, Epsilon. The methodis illustrated by modelling a small real-life steam generator example andsubsequent automated analysis of its properties.Keywords: Control system analysis; formal specification; formal verification; real-time systems; standards

Formal Modeling and Analysis of an Audio/Video Protocol: An Industrial Case Study Using UPPAAL

A formal and automatic verification of a real-life protocol is presented. The protocol, about 2800 lines of assembler code, has been used in products from the audio/video company Bang & Olufsen throughout more than a decade, and its purposeis to control the transmission of messages between audio/video components over a single bus. Such communications may collide, and one essential purpose of the protocol is to detect such collisions. The functioning is highly dependent onreal-time considerations. Though the protocol was known to be faulty in that messages were lost occasionally, the protocol was too complicated in order for Bang & Olufsen to locate the bug using normal testing. However, using the real-time verificationtool UPPAAL, an error trace was automatically generated, which caused the detection of “the error” in the implementation. The error was corrected and the correction was automatically proven correct, again using UPPAAL. A future, and more automated, version of the protocol, where this error is fatal, will incorporate the correction. Hence, this work is an elegant demonstration of how model checking has had an impact on practical software development. The effort of modeling this protocol has in addition generated a number of suggestions for enriching the UPPAAL language. Hence, it’s also an excellent example of the reverse impact

Danfoss EKC Trial Project Deliverables

This report documents the results of the Danfoss EKC trial project on model based development using IAR visualState. We present a formal state-model of a refrigeration controller based on a specification given by Danfoss. We report results on modeling, verification, simulation, and code-generation. It is found that the IAR visualState is a promising tool for this application domain, but that improvements must be done to code-generation and automatic test generation