Interface and connection model in the railway traffic control system

Abstract

The article presents a model of connection of ETCS application and classical base layer equipment. The model distinguishes three layers: physical, logic and data, which require different modelling techniques and at the same time must be consistent. The model will form the basis for the digital mapping in the Digital Twin of the ETCS application. Layer division is a natural way to represent the structure of a device and its operating rules. It allows a detailed and structured representation of the interfaces of a connection and then an analysis of the connection both with respect to the layer of interest and from the point of view of the interaction between features in the different layers. The S-interface of the LEU encoder of the ETCS is described, taking into account different solutions encountered in practice. The conditions of the connection between the LEU encoder and the environment form a description of one of the two boundaries between the ETCS application, i.e. the implemented ERTMS/ETCS on a specific area of the railway network, and the environment. A general connection model and definitions of a connection and an interface are presented. As an example, the electrical connection with signals transmitted through galvanic connections has been assumed to be typical for LEU encoder and track-side signalling control circuits found in base layer equipment. The physical layer is described in terms of physical parameters and their values. The parameters are divided into electrical (current, voltage and frequency) and mechanical ones (number of leads, conductor thickness, etc.). The values of the electrical parameters are expressed in terms of a uncountable set with defined limits. The logic layer was described in a vector-matrix form. Logic signals are assigned to electrical signals with specific physical parameters. The data layer contains information about the assignment of specific telegrams to specific electrical signals.