Why we are where we are
Automation networks tend to be clusters of inter-connected and inter-related devices working towards a common outcome. Historically these devices were interconnected using proprietary tranmission techniques based upon the multi drop RS485 protocol; whilst limited in size and often unrelaible the serial fieldbus did enjoy a degree of security from its obscurity. The global desire to lower cost and increase reliability across both short and longer distances allowed Ethernet, a technology that came about in the enterprise ‘IT’ LAN, to move in to the automation ‘OT’ space.
With no other threat than a simple cable break to worry about in the mid-late 1990’s the introduction networking Company Hirschmann introduced the Hiper Ring and, overnight, solved the main objection of deployment at Plant and Control Networking layers – rapid resilience.
The Automation players tried to fight back but picked upon the weak and largely historical argument of ‘determinism’ – the lack of – as the reason their Customers should remain locked in to their proprietary, high cost and often inflexible networking standards. This view is supported as the determinism objections seemed to just dissappear with the wind once each of these vendors later introduced their own rangees of devices with an Etherent interface.
Editors view: Had the argument against Etherent been more considered and security selected in place of determinism, automation system networks would look very different today. That horse has well and truly bolted and we are where we are; now we need to embrace the benefits (of which there are many) and think about what we can do to make our automtion ‘OT’ networks as robust and secure as possible.
Flexible, Fast & Reliable Networking
The technology dates back to 1973 when Bob Metcalf developed the concept as a shared, high-speed, medium for transmission. The original shared ’10Base5 / 10Base2 / 10BaseT (hub)’ technology implementation became a victim of its own success and evolved into the switched platform now common place. Transmission speeds have increased 1000 fold over the years with backbones now able to operate at up to 10Gbps.
More typical speeds deployed in Automation projects are 1Gbps for Server connection and the distributed backbone. Access devices connect at 100Mbps.
The emergence of full duplex transmission in the late 1990’s and the wire speed forwarding that became common place in 2000-2005 issues of determinism have been largely eradicated. Recent enhancements to the technology include Zero Loss Ethernet and Real Time Ethernet engineered to satisfy the most stringent and time sensitive of application.
Devices have evolved for certified operation in extreme environments. These include rail, where vibration and the environment are the issues, and power where electro magnetic interference, highly accurate timing are key drivers. Industrial strength products can be securly mounted in every automation environment, they can also provide power to the devices attached making them more of a utility to the automation system.
The more general switching opportunity of today relates to network optimisation and getting to grips with the challenges of network security.