Extending the railway section between Kokkola and Ylivieska from a single to a double track section was one of the most comprehensive signalling system projects ever conducted in Finland. As it is one of the country’s busiest lines, where trains reach up to 200 km/h, rebuilding of the existing and adding the second track had to be done without affecting regular train operation. After the operator, Finnish Transport Infrastructure Agency, decided to implement a Mipro Interlocking based on COTS PLC, they investigated to find solutions that would interface with this system in an efficient and cost saving way.