“Why Ethernet?” That was a question posed to me during a recent meeting with a plant manager. He said, “I have been using serial Fieldbuses for many years, but now I hear nothing but Ethernet, IoT, digitization, industrial revolution, IT/OT convergence and alike. There is a lot of noise about the great things it will do for us; without specifics. Why and how exactly? I am not against changes that are meaningful, but I want to make an investment that lasts. What exactly would switching to Ethernet give me today and into the future? You see, I am a pragmatic person…”
Well, these are great questions, I thought. “So, let’s take a closer look together”, I proposed. “Let’s start with your investment: you want it to give you return today and tomorrow. What exactly do you have in mind?”
“Scalability” was his response. “All right…” and I started sketching topologies connecting devices in stars, rings, daisy chains, long distance fiber and even long haul and short distance radio. I continued by adding new devices or subsystems to free ports in one of the switches, without ruining the previous architecture. “You see it’s adding, not re-wiring,” I explained. “Yes, it is expandable”, he agreed. “Well, it would be much easier to modify applications, configuration and even firmware in devices from a single point” He took my pencil and added to the drawing. Then I showed him how to migrate from Modbus TCP to Ethernet/IP with the same PLCs, how to connect legacy Fieldbuses to the latest controllers, and embed them right into the Ethernet backplane. We spoke about a full range of available controllers, RTUs and devices that come Ethernet enabled.
“I am with you”, he continued. “But won’t it be complex? I’m looking for a simple solution that I can get up and running quickly.” And so we continued; new sketches popped up on our paper when we lowered the installation time by using one set of cables for all his needs. We settled on fully open standard IP-based networking protocols (such as EtherNet/IP and Modbus TCP, web services and selected standard IT protocols). We reduced learning time with a complete Ethernet-based solution for operations (plant, machine, telemetry) and SCADA management systems. We sped up the setup time with uniform engineering software tools and network transparency. We even increased his innovation rate with easier integration of third party solutions as a result of using only the open standards.
For sure efficiency of operations was important to him. We looked at the productivity brought about by real-time performance due to 100 or 1000 Mbps full duplex connectivity, integrated and embedded switches for avoiding traffic collisions, traffic prioritization capability etc. We mixed slower Modbus TCP for power meters with fast EtherNet/IP scans in the same controller. We viewed embedded websites in the Ethernet devices and used Internet, standard web browsers and mobile applications, as well as network and monitoring software to view his operations locally and remotely. We agreed that with a library of applications and the transparency offered by Ethernet everywhere (with no conversions from protocol to protocol) he could adapt applications more rapidly than ever before.
“And I can’t forget about maximizing operational uptime,” he said. When we looked closely, an Ethernet solution, again, turned out to be superior to any other traditional Fieldbus. I drew some of the self-healing mechanisms that we offer to our customers, such as redundant ring, I/O ring, Hot Standby SCADA, Hot Standby PLC, fast device replacement mechanism that provides self-configuration of the replacement device.
“One more important topic,” he said. “How do I protect my system from cyber threats, isn’t that a real problem with an Ethernet network?” I explained the ‘defense in depth’ approach that we recommend. We touched on methods used for physical protection with IP cameras, perimeter protection with firewalls, network segmentation with switches, and a need to work with vendors that protect their devices against cyber security.
A picture is worth a thousand words; therefore I invite you to download the illustrations we created during our conversation, which I transferred to a more traditional power point.
You may also be interested to review the Ethernet offers that Schneider Electric has today for our industrial customers.