Design of core blocks and implementation on a programmable logic controller for a train signalization system

In order to ensure the security of each set of tracks, signalization systems are build track specific, even though they have similar building blocks. In this Project it is aimed to design a modular, adaptable signalization system, while sticking to the asked conditions and safety measures and implement it on a programmable logic controller (PLC). First order of business was to design the general architecture of the whole system while complying with the interlocking systems safety regulations. Afterwards the main blocks that were used to build the larger system (rail block, intersection block, route block and signal block) were designed using the automata approach. The PLC´s that were planned on being used in the future belonged to Siemens S7 family. Accordingly Siemens´ SIMATIC STEP 7 software was chosen to define the inputs, outputs, events, cases and functions and to finally simulate them all.