Ethernet for the plant floor

What does 'Ethernet-enabled' mean? It means you plug it in, and that's it," begins Victor Wegelin, instructor of Industrial Data Communications, a training course (TS05) offered by the Instrument, Systems, and Automation Society (ISA). Wegelin emphasized the importance for plant engineers and others outside the IT department responsible for control system maintenance to understand the technolog...


What does 'Ethernet-enabled' mean? It means you plug it in, and that's it," begins Victor Wegelin, instructor of Industrial Data Communications, a training course (TS05) offered by the Instrument, Systems, and Automation Society (ISA). Wegelin emphasized the importance for plant engineers and others outside the IT department responsible for control system maintenance to understand the technology and issues involved in successful installation, commissioning, and operation of industrial control networks. Networks used exclusively for industrial control generally are used and maintained by people who are not communications specialists.

The seminar, held in June at the Hilton, Lisle, IL, explained the special requirements that industrial control networks have beyond business networks. According to Wegelin, industrial networks require predictable throughput and scheduling, extremely low downtime, and scalable size. These networks must be robust enough to operate reliably in harsh, and sometimes hazardous, environments. Most process network systems modify technology borrowed from business networks.


The bulk of the seminar centered on Ethernet and TCP/IP. Wegelin defined protocol as a "set of rules that determine how two devices should communicate." The tasks required of protocols are:

  • Error detection and correction

  • Routing messages through complex networks

  • Data encryption and security

  • Consistent signal levels among devices

  • Network addressing.

    • Layers

      There are many protocols. Trying to make sense of them is like eating alphabet soup. To organize them and understand how they interact, protocols typically are arranged into layers, grouping them by related tasks. For example, protocols that deal with the physics of message transmission, such as signal frequency, voltage level, and cable design, are grouped together.

      Wegelin likened Ethernet to the U.S. Postal Service. Send the message in the proper format and protocol, and it gets to where it is supposed to go.

      Protocols govern the way a letter is sent and received. The recipient receives and understands the message because proper protocols were followed. Not following appropriate protocols is like sending a message in a bottle β€” it may miraculously get to the intended recipient, but probably not.


      In 1977, International Organization for Standardization (ISO) developed a 7-layer model β€” called the Open Systems Interconnect Reference Model (OSI/RM) β€” for organizing data communication protocols. These layers are as follows:

      • Layer 1 = Physical

      • Layer 2 = Data link

      • Layer 3 = Network

      • Layer 4 = Transport

      • Layer 5 = Session

      • Layer 6 = Presentation

      • Layer 7 = Application

        • Wegelin discussed industrial protocol suites, such as Modbus, Modbus+, and AB DH+ as well as how they compare with commercial suites. He covered each layer of the model thoroughly, providing plant floor examples frequently. Wegelin said that it is important to understand that Ethernet is not a complete network on its own; it needs upper protocols.


Top Plant
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2017 Top Plant.
Product of the Year
The Product of the Year program recognizes products newly released in the manufacturing industries.
System Integrator of the Year
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
May 2018
Electrical standards, robots and Lean manufacturing, and how an aluminum packaging plant is helping community growth.
April 2018
2017 Product of the Year winners, retrofitting a press, IMTS and Hannover Messe preview, natural refrigerants, testing steam traps
March 2018
SCCR, 2018 Maintenance study, and VFDs in a washdown environment.
April 2018
ROVs, rigs, and the real time; wellsite valve manifolds; AI on a chip; analytics use for pipelines
February 2018
Focus on power systems, process safety, electrical and power systems, edge computing in the oil & gas industry
December 2017
Product of the Year winners, Pattern recognition, Engineering analytics, Revitalize older pump installations
Spring 2018
Burners for heat-treating furnaces, CHP, dryers, gas humidification, and more
April 2018
Implementing a DCS, stepper motors, intelligent motion control, remote monitoring of irrigation systems
February 2018
Setting internal automation standards

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

The Maintenance and Reliability Coach's blog
Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
One Voice for Manufacturing
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Maintenance and Reliability Professionals Blog
The Society for Maintenance and Reliability Professionals an organization devoted...
Machine Safety
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
Research Analyst Blog
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Marshall on Maintenance
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
Lachance on CMMS
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
Maintenance & Safety
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
Industrial Analytics
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
IIoT: Operations & IT
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Randy Steele
Maintenance Manager; California Oils Corp.
Matthew J. Woo, PE, RCDD, LEED AP BD+C
Associate, Electrical Engineering; Wood Harbinger
Randy Oliver
Control Systems Engineer; Robert Bosch Corp.
Data Centers: Impacts of Climate and Cooling Technology
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
Safety First: Arc Flash 101
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
Critical Power: Hospital Electrical Systems
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me