ENCE V4: new Electronic Interlocking System

The project aims to develop a new interlocking. The V-cycle development standard is followed and tasks are performed at the system level (ENCEv4 as a whole), subsystem (hardware, platform softaware and application software), and component. Therefore, tasks of specification, design, implementation and unit tests are carried out.

The complete system, the subsystems and the majority of the components are considered critical safety elements, for which they are entitled to the SIL-4 level according to the CENELEC EN 50129 standard. The Electronic Interlocking is divided into three subsystems: the hardware, software of platform and application software.

The hardware is prepared to communicate, either with digital inputs and outputs or through protocols with the different field elements such as signals, needles (engines that control the tracks that allow the train to change its direction between one track or another) or beacons (device which emits electromagnetic signals that allows communication between the track and the train), among others.

The platform software controls the hardware and manages the operating system. The main objective of this software is to make the upper layer (application software) of the hardware independent. In this way, development is optimized, field installation is facilitated and the application software is made independent of possible changes in the hardware.

With respect to the application software, ENCE V4, is broken down into different modules to form a final application that can be tram, conventional train or high speed. This SW controls the field elements and safety logic that allows the safe movement of railway convoys. The most important criteria for the development of these components are safety, the flexibility to adapt to the clients and regulations of each country, the ease of deployment in the different interlocks and maintainability.

New electronic interlocking card:

In addition, within this project the hardware platform and the firmware of the various programmable logic devices of the new PCB cards for Electronic Interlocking are designed, programmed and validated. Each card is composed of microprocessors, programmable logic devices (FPGA), ADC (Analog-to-Digital Converter) devices, DC-DC converters, etc., which support various communications protocols, serial, Ethernet. They are multifunctional, that is, the same card allows a different number of functionalities that implies greater modularity, which allows reducing costs, production efforts and validation.

In this sense, after the design and production of the PCB cards, unit tests of validation of the hardware prototypes are carried out, where the design specifications and functionalities are checked; In addition, test standards are used to validate the serial production of the hardware. Regarding firmware, Bench Test is carried out to verify the suitability of its design and development.
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Technical guide:
• Project type: Railway.
• Ad Maiorem participation: development of embedded software for various railway signalling systems and products.
• Location: Madrid, Spain.
• Year: 2019.
• Relevant technology:
- VectorCAST
• Programming:
- C
- SCADE