The international rail market has great potential with above average growth rates predicted for the next three decades with an inclinination towards digital technology
Within this context, the industry is in the midst of a change from costly proprietary safety technology to open source, commercial off-the-shelf (COTS) controllers that provide flexibility and cost saving for digital rail transport.
More and more vital control processes are being implemented as cloud- or internet-based solutions. In the digital age, safety controllers form the basis for critical applications such as level crossings, rolling stock and interlocking.
In addition, the interplay of safety and security is becoming increasingly important, and in the ‘Rail 4.0’ era, COTS controllers can be more flexible and more economical than proprietary safety technology.
The question of which is preferable – proprietary safety technologies or standardized, COTS solutions – is currently a hot topic. COTS designates series production controllers, which are sold in large numbers and deployed in a variety of industry sectors.
Thanks to the use of standard components, they are significantly less costly than proprietary systems, while at the same time fulfilling all important safety standards of the railway industry. The global market share of COTS controllers in safety-related electronic systems is expected to be about 25 per cent by 2020.
COTS vs proprietary systems
Historically, the railway industry was slow to change. It did not help that for the past decades, technological advancement was relatively sluggish in the rail industry.
Now, with the advent of digital technology resulting in lower cost of COTS, more stringent compliance requirements and the need for flexibility and scalability, there is a clearly visible trend toward COTS components as the new standard.
Proprietary safety systems are developed and produced in small quantities. That makes them more expensive than COTS systems and it limits their application flexibility. After original equipment installation, users are ‘forced’ to procure follow-on systems from the same manufacturer, which is often the control system supplier. By contrast, COTS systems are standardized, produced in large numbers and have a prior track record in numerous applications outside the railway industry.
Using standard components gives railway operators flexibility in their choice of suppliers and allows them to select the “best of breed” solution for each application, including safety technology.
A decisive prerequisite for the digital railway era is the networking of a wide variety of systems for data exchange. Here as well, COTS safety controllers have an advantage over proprietary solutions because the interfaces of conventional systems are not standardized. That can make it difficult to integrate those solutions into existing heterogeneous automation architectures. Due to proprietary programming, in many cases only the controller manufacturer is able to carry out upgrades, updates and maintenance.
By contrast, COTS controllers have operating systems that are based on globally available standard programming languages compliant with IEC 61131. They also support interfaces for all major communication protocols, including Ethernet, TCP/UDP, RS485, RS422, RS232 and CAN. Standard industrial protocols are used for communication.
Many people come into contact with a safety controller during its long lifetime. They include hardware and software developers, operators and users – train drivers, maintenance staff, assessors, inspectors from approval agencies and commissioning technicians.
Consequently, the system should be as simple and intuitive as possible. The objective is to make it as easy as possible for all people who deal with vital matters every day to operate safely and reliably, and manage very complex machines such as railway vehicles. Reducing the complexity of safety systems also reduces the cost of training service employees.
Presently many railway applications are an eclectic collection of proprietary technology, often consisting of several generations of equipment. This lack of standardization and modularity makes maintenance and system extensions both complicated and costly.
Standardization and the widespread use of industry-standard programming languages compliant with IEC 61131 make COTS controllers easier to use and maintain, making operating and life cycle costs significantly lower in comparison to proprietary technology with the same level of safety.
Due to the required long-term availability of safety controllers in rail transport, in part made necessary by the long useful life of rolling stock, future viability is an important evaluation criterion. The acceleration of adopting digital technology and ever-shorter innovation cycles increase the significance of this aspect. With proprietary technology, the cost of keeping the solutions constantly up to date is relatively high due to the small production volume.
For users there is also a risk that the product may no longer be available for the next application. The standardization and widespread use of COTS systems will give users more planning security. That also applies to the availability of spare parts and software updates. Moreover, COTS controllers comply with the strict SIL 4 standard in accordance with CENELEC, the European Committee for Electro-technical Standardisation.
With their modular structures, standard communication interfaces, and stringent safety compliance, COTS systems are easy to adapt to changing needs arising many years later.
Indonesia joins the future
Independent provider of smart safety solutions, HIMA, recently signed a strategically significant contract with Indonesian rail supplier PT Len Industri (Persero).
The Indonesian company is state-owned and produces railway systems, including railway signal systems for the local rail industry. Under the contract HIMA is to upgrade the safety technology at 25 railway stations in Indonesia.
A major factor in awarding the $2.1 million project to HIMA was that HIMA equipment uses open source communication architecture, making its controllers simple to integrate with other equipment and to configure. The open architecture allows PT Len Industri to seamlessly integrate HIMA’s technology with its own legacy systems and with technology from other vendors.
Sedat Sezgün, is head of rail at HIMA
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