d-SC is exclusively based on open industry standards in hardware, software and communication, allowing the end user to stay vendor independent and protected against obsolescence issues:

• Standard PC hardware architecture with state of the art x86 host controller
• Standard 19” CompactPCI industry standard
• Standard operating systems (QNX, Linux)
• Standard Ethernet communication with safe real time EtherCAT
• Standard communication interfaces to TCN network, MVB, CANopen , ProfiNet etc.
• Standard POSIX programming interface for “C”

d-SC separates the control electronics (the computer hardware) from the control function (the application software).

d-SC opens up the essential interfaces between the control electronics and the application.

As a totally open platform, d-SC is the first railway computer that makes rail service suppliers and rail operators independent from a solution provider, giving them full control over their project.

d-SC is modular in terms of hardware based on its proven 19” CompactPCI technology:

• The MH50C controller can be configured with the exact number of required safe I/O channels, and non-safe functions based on standard CompactPCI boards.

d-SC is modular in terms of I/O location:

• Up to 63 remote I/O boxes (with four to eight boards per device) can be connected to one MH50C controller, saving huge wiring cost and increasing the operation stability.

d-SC is modular in terms of software:

• Ready to integrate all state-of-the-art real-time operating system BSPs, with QNX being used as the standard operating system
• Ready to mix and match RTOS for safe functions with Linux for non-safe functions
• Ready to communicate via the EtherCAT standard real-time variant of standard Ethernet
• Ready to start programming based on different standard environments

d-SC is modular in terms of certification:

• As the complete d-SC solution may contain “safe” and “non-safe” parts, different SIL 4 certification packages are provided.
• All certificates are available either for the hardware only or as a bundle together with the safe components of the QNX real-time operating system.

• d-SC is the central computer platform for on-board ATO and ATP (Automated Train Operation and Protection) functions.
• d-SC can be the heart of a CBTC (Communication Based Train Control) system.
• d-SC interfaces to all existing train communication standards such as MVB, WTB, CAN etc.
• d-SC interfaces to the outside world via wireless communication using GSM-R, GPS, WLAN etc

• d-SC is compliant with the EN 50121-4 standard for wayside EMC regulations describing the emission and immunity of the signalling and telecommunications apparatus.
• d-SC is the central computer platform for electronic interlocking in signalling control systems.
• d-SC can be used as central computer in ATO/ATP applications e.g., Zone Controller, platform screen door controller, etc.
• d-SC can be used to as control unit for any kind of trackside assets such as level-crossings, signals, LEU, etc.
• d-SC covers a part of the functions of the European ETCS as well as, e.g., CTCS, ATMS, PTC or Klub-U.

• d-SC consists of SIL 4 hardware and software components pre-certified according to EN 50126, EN 50128 and EN 50129, leading to a significant time and cost saving for the end application.
• A single F75P (safe CPU board) or MH50C (safe d-SC controller) is already a 2oo2 unit according to EN 50129. 2oo2
• The MH50C is designed to be fail-safe.
• It supports double execution of software on two redundant processors.
• It supports cross-checking between two redundant processors.
• The safe communication with the I/O is based on safety protocols.

The QNX real-time operating system is well established on an international level and offers a broad range of development tools.

The safe QNX Neutrino microkernel supports partitioning of the application. Partitioning saves cost and development time by:

• Separating safe and non-safe functions on the same platform
• Combining different SILs on one platform, e.g., SIL 2 for ATO and SIL 4 for ATP

In addition, the microkernel structure allows to separate application processes from protocol stacks and drivers.

QNX also supports message passing, allowing the application to cross processor boundaries.

d-SC can be used together with other safe operating systems, too:

• d-SC is prepared to support GreenHills Integrity, Sysgo PikeOS and Wind River VxWorks 7 Safety Profile.
• A demo BSP for PikeOS is available from Sysgo.
• Integrity and VxWorks 7 Safety Profile will be made available on request.

• Linux – because it is open source, independent of the hardware platform, it offers a huge variety of freely available development tools as well as peripheral drivers and is used worldwide. Why does it make sense to separate the safe from the non-safe applications at all?
• The combination of two operating systems – QNX and Linux – on one hardware platform – d-SC – limits the effort of application programming to the safe parts. This makes the software development and the subsequent certification easier and faster, resulting in significantly reduced overall cost.
• Thanks to the abstraction of the periphery, the application can make use of the broad offering of peripheral Linux driver support.

• Yes – and: using an open system like d-SC means that product obsolescence management can be limited to single standardized parts of the computer system. It will never affect and endanger the train or wayside function itself.
• duagon guarantees long-term availability of all parts of the d-SC for a minimum period of 10 years in order to best meet the specific requirements of railway applications.
• For the successor of the safe CPU board duagon will provide a BSP with identical APIs, so that the source code of the application can remain unchanged.