In this paper we present a verification strategy for signalling principles for the control of a railway interlocking system written in ladder logic. All translation steps have been implemented and tested on a real-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development of a mathematical model of a railway interlocking system and the trans...

In this project the verification of safety conditions for the control of a railway interlocking system written in ladder logic is carried out. All translation steps have been implemented and tested for a real-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development of a mathematical model of a railway interlocking system and the translatio...

An input constrained channel S is de ned as the set of words generated by a nite labeled directed graph It is shown that every nite state encoder with nite antici pation i e with nite decoding delay for S can be obtained through state splitting rounds applied to some deterministic graph presentation of S followed by a reduction of equivalent states Furthermore each splitting round can be restri...

One of the main themes in the area of Terminologi-cal Reasoning has been to identify description logics (DLs) that are both very expressive and decidable. A recent paper by Schild showed that this issue can be prootably addressed by relying on a correspondence between DLs and propositional dynamic logics (PDL). However Schild left open three important problems, related to the translation into P...

Throughout the ages people have been working in research institutes and industries in machine automation so as to have less involvement of operator in machine operations. In the development of automation controllers the trend has been to move towards soft controllers so as to provide better control, more flexibility and more reliability with intelligent diagnostics of machine faults. So industr...

In this paper we present a verification strategy for signalling principles for the control of a railway interlocking system written in ladder logic. All translation steps have been implemented and tested on a real-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development of a mathematical model of a railway interlocking system and the trans...

In this paper we present a verification strategy for signalling principles for the control of a railway interlocking system written in ladder logic. All translation steps have been implemented and tested on a real-world example of a railway interlocking system. The steps in this translation are as follows: 1. The development of a mathematical model of a railway interlocking system and the trans...

A method is described for modelling, verification and automatic generation of code for PLC controllers. The requirements for a controller are modelled using UML state machine diagram, with a formal semantics given by a finite state time machine. The model can automatically be converted into a timed automaton, embedded into a model of the environment (a controlled plant) and verified against saf...