Controlling and managing a complex system is difficult at any time. However, users in the process (for example, water, petro-chemical) and infrastructure industries such as surface rail, airports or underground metro systems have the added complexities of having to do the same over extreme distances with the possibility of thousands of I/O points.
Furthermore, in these application environments there is often the added challenge of safety and security; if there is a failure then very often there are direct implications on both humans and the natural world. Therefore it is no wonder that users in these application environments take only the very highest levels of care and exercise the strongest risk management processes, which means new concepts need extensive testing. So when Mitsubishi Electric and their e-F@ctory Alliance partner, Raima, both long-term suppliers to these industries, put their heads together to solve one common customer’s problem it was inevitable that a strong solution would result.
The problem in focus was the monitoring and tracking of many thousands of assets on a sub-terrain metro line: how to do this in a cost-effective, reliable and secure way.
Industrial control, process automation and transportation industries have struggled for years with the problem of integrating efficient data management within its applications. This is mainly due to the strict safety and security requirements which are normally very costly to meet. Developers of these systems incur large expenses in analysing and testing as well as automation software to prevent any possibility of system catastrophic failure.
Raima and Mitsubishi Electric decided one approach would be to use existing, approved approaches, designed for purpose and combined in to a single system. This would be easier than trying to force traditional approaches to solve issues they were never designed for.
Raima was already strongly positioned in the field of secure data management with combinations of server, PC and embedded solutions which could transfer and manage data in a predictable and repeatable way.
Features such as ACID-based data replication and data encryption, as used in Bank ATMs to ensure data is seamlessly and reliably transmitted, as well as the use of a networked database concept, which has a predictable speed impact, were critical to this approach. Another key aspect was to design the system architecture as a distributed database, i.e. it was planned that small local databases (based on RDMe) were to be embedded in the local PLC; this is where Mitsubishi Electric picked up their part of the system.
PLC and PAC control
As a long-term proven supplier to both surface and sub-terrain rail transit, Mitsubishi Electric’s PLC systems have proven themselves reliable and safe over many applications. When the discussions with Raima turned to issues regarding distributed data management, Mitsubishi Electric already had a useful platform: the iQ Platform. This combination of PLC and PAC control was suitable to solve the problem of how to embed a fully operating database in a non-PC environment, yet retain the reliability and security of industrial PLC control. The use of the iQ platform’s C Controller was a good option to host the Raima RDM embedded database as it seamlessly integrated with the PLC control function through the iQ Platform. The C Controller also provided industrial reliability, with no moving parts, high environmental resilience and a fully C compatible environment, meaning it was not susceptible to the normal issues around PC security.
The combination of these two core technologies provided the rail operator with a secure and reliable system; however, that was not the end of the discussions.
Working closely with another e-F@ctory Alliance partner, Green Hills Software, Raima and Mitsubishi Electric enhanced the system security and operability further by changing the operating system of the main central database server to the Green Hills INTEGRITY RTOS. This real-time operating system (RTOS) has a Separation Kernel architecture that allows the server to be built using technology that effectively enables isolated user environments, or partitions, to be created. These multiple secure partitions can host real-time applications and/or guest operating systems on a single server. By using this, and hosting the central Raima database in one of these secure partitions, it was possible to create a certifiable system. The result was a high-reliability server with distributed high-reliability field controllers that were linked by a high-reliability database, all with security and industrial performance; suitable for the mass transit systems which need maximum up time, a demand also seen in process industries.
This deceptively simple approach proved to be a good example of how the e-F@ctory Alliance brings together technologies to create new approaches, and how motivated companies can come together to provide customers with the competitive advantages needed.
For further information about secure data handling and the e-F@ctory Alliance, please visit automation.mitsubishielectric.co.uk.