Is IoT (IP to the edge) good for automation?

  • January 19, 2015
  • Feature

By Bill Lydon, Editor

The Internet of Things (IoT) definition as promoted by major industrial automation suppliers and computer industry suppliers is “IP to the edge.” IP to the edge means using Internet Protocol over wired or wireless Ethernet to communicate with end devices. The assumption is IoT won’t exist until everything is exposed to the Internet and we are able to get information from and perform control of end devices. This concept may not be common sense engineering and sound system design for industrial automation systems. The goal in manufacturing is to improve system results and not necessarily to connect every sensor, relay and other end devices to the Internet. A major benefit of IoT concepts includes acquiring a broader set of data, analyzing it to gain insights, and taking action to improve outcomes. This can be accomplished using new technology tools, applying common sense, good system design, and engineering principles without connecting everything to the Internet.

Confusing Goal with Implementation

There is an adage in design; it describes engineers that are captivated by a new technology and they look for any application to try it:

“Give a kid a hammer and everything is a nail.”

This is a variant of Abraham Maslow's law of the hammer from his book, The Psychology of Science, published in 1966. The author writes about how people can get fixated on something and believe that it is the answer to solving every problem. Pushing Ethernet to sensors, motor controls, and other basic end devices may well fall into this category.

Ethernet Implementation

Some industrial automation vendors already offer products with direct Ethernet connections to sensors, drives, and other devices. This is not an inherently bad design but has negative implications in some industrial applications. Ethernet is good for networking controllers and other devices that consume and produce large volumes of data. However, it has significant shortcomings for industrial end devices while it increases complexity and cyber risk.

Ethernet requires point-to-point wiring to switches and therefore increases the number of field connectors, terminations, and installation labor. Adding more connectors in a control cabinet increases the risk of introducing unacceptable signal distortion and could lead to poor communications over time. In system reliability analysis, connectors are one of the largest contributor’s to risk of failure and logically lowers plant availability with lower MTBF (Mean Time Between Failure) hours.

Ethernet switches are active computing devices that increase complexity and create another significant point of failure. The user needs to understand Ethernet switches and their configuration, which includes creating and assigning VLANs, Network Address Translation (NAT), and port security. Since Ethernet switches are active devices, maintenance is more complex and includes traffic monitoring, performance monitoring and updating firmware. They require special troubleshooting knowledge, know-how, and skills.

Traditional industrial networks, like DeviceNet, Profibus and Modbus, are multi-drop networks and require less installation labor, system administration, and cyber security protection.

The complexity of cyber security protection increases with additional Ethernet nodes in a network. At the 2014 Rockwell Automation Perspectives Event, CISCO’s Bret Hartman, Vice President and Chief Technology Officer Security Business Group, noted that it is impossible to secure each device. Cyber security requires active inspection of network traffic with deep packet inspection and other new methods.

Illustrating this increased complexity, a Motor Control Center (MCC) with starters and other devices each connected to Ethernet requires hardened Ethernet switches to be located in the MCC cabinets. Each device needs to be homerun connected to the Ethernet switches with special Category 5e Ethernet heavy 18 AWG (1.024 mm diameter wires), 600V listed cables. This requires more installation labor than other multi-drop industrial networks. Wires in a standard Cat 5 cable are AWG 24 (0.511 mm diameter), less than half to size.

IoT Going Forward

I believe a number of new technologies spawned by IoT developments will help create more efficient and responsive manufacturing. Fortunately, the automation industry has a number of refined and proven industrial network standards that are capable of satisfying the communications requirements of edge devices. These standard networks are reliable and offer simple engineering and installation. They can be connected appropriately with gateways to maintain systems integrity. Today, a number of suppliers offer gateways for this purpose. Intel understands this gateway need and has launched Intel Gateway Solutions for the Internet of Things (IoT). It is a chip solution that includes a 32-bit processor bundled with pre-validated integrated software from Wind River and McAfee for embed cyber security.

Bright shiny new technology is great if applied using sound logic and design with a thorough understanding of the application.

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