High-capacity solutions

Solutions implemented thanks to SITE's internal Research&Development division for the safe management of railway lines, of axle detection in an innovative management of multi-section segments.

Digital Infill

Developed by SITE’s R&D unit, the system allows a safe management of the early release of the train control system. Applied within the national SCMT system it improves the regularity of the service. Among the most typical uses it enables a safe early release of the train control system after: a delay in the opening of a first category signal; a restart from a passing track having an off-centre signal from the regular passenger-train stop.
  • digital integration and control of the Infill Code
  • high power for its application on wide tracks sections
  • Modularity and versatility for various systems
High quality generation of 420@178Hz (NFILL) code through digital synthesis:
  • high definition of the wave shape
  • high precision and repeatability of all parameters of 420@178Hz code
  • code synthesis aiming at increasing reliability (innovative characteristic of the code application once sinusoid 178Hz curvatures are completed)
  • adjusting the power to supply depending on the electric characteristics of the track circuit to serve
High power availability and top performances:
  • high power availability (250VA) to supply to the track way (long distance coverage)
  • low power dissipation thank to the performances of the switching amplifier
  • improving consumptions by adjusting the power to be supplied to track circuit
Intense modularity being an INFILL function oriented system
  • enables the improvement of the INFILL functions useful for each station
  • no dependency restrictions between INFILL functions executed at each station
Ergonomic principles of the equipments installed on FS relay back plates
  • installation on horizontal relay structures made of 2 or 3 rows (in case of 3-rows structures, each of 3 INFILL function can use a dedicated independent mixer)
  • installation on vertical relay structures made of 2 or 3 rows (in case of 3-rows structures, each of 3 INFILL function can use a dedicated independent mixer)
  • installation in standard rack 19’’, choosing heights depending on the number of systems to include
RAMS aspects:
  • SIL4 system
  • High general availability of Infill functions at stations in case of one of the systems failure
  • Corrective maintenance programs to employ on each Infill function
Infill 420 code is a 178 Hz sinusoidal signal modulated by 420 cpm (7Hz) frequency square wave generated and habilitated towards the track, thank to the information acquired from IS system.
Interface with codified track circuits is made through the use of a mixer enabling the INFILL code transmission to the track, together with the block codes on primary band. For those systems not having previously installed a mixer, SITE provides a self designed dedicated one.
DIGITAL INFILL system realizes INFILL function, using digital integration and control techniques of the generated signal.
Infill function is SIL4 safe, through a 2002 digital architecture executing controls over the generated signal, and intervening, if applicable, by addressing the signal to a safe status.


Developed by SITE’s R&D unit, the system puts together the advantages of axles counting schemes with innovative multi-section management procedures, by using a vital redundancy platform. Axle counting system determinates the occupancy status of a train on its related track section according to: simple rail, either multi-section and mono-section; double rail, either multi-section and mono-section. The system manages the presence of track-deviations.
  • Realisation of wide sections, through the use of auto-reconfiguration functions
  • Self-release of the track lines
  • Life digital communication protocol
SITE Multi Rail Lock system is characterised by a distributed architecture, enabling the installation of the system on different geographical and topological areas. The system architecture allows the distribution of all interface functions with line side equipments on axle count points, so-called PCA-R, maintaining a centralised control over the functions of the system in the main BCA-R unit.
The system enables a certain flexibility for the physical allocation of the points, satisfying the widest needs for the infrastructure management:

La flessibilità consentita dal sistema per quanto riguarda l'allocazione fisica delle unità può soddisfare un ampio ventaglio di esigenze dei gestori delle infrastrutture.
  • 1 to 32 inputs
  • Ethernet LAN/WAN communication through optical fibre or copper (coaxial cable, STP cable, railway pair cable)
  • Interface with relay signalling systems through dedicate and remote input/output by ensuring SIL4 safety transmissions in compliance with EN50159
  • Highly redundant system:
    • electronic on 2003 internal architecture
    • optional redundancy of the connections on LAN/WAN network
    • optional redundancy of the axle count sensor unit (up to 2 for each count point)
    • optional redundancy for input count points
SITE Multi-Rail Lock system offers the following functions:
  • Innovative self-release function (multi-sections application)
  • Innovative auto-reconfiguration function on multi-section applications at the presence of a fault (multi-sections application)
  • Managing 1 or 2 detectors for each axle count point
  • Managing release keys, conditioned and unconditioned
  • Controlling and diagnose information on SNMP protocol
  • Complete configurability of the system topology by the railway infrastructure manager
  • Determination of trains occupancy status of high-speed sections