Commercial Ethernet vs Industrial Ethernet

What are the similarities and differences of Ethernet cable, and what does it mean for your next factory automation project? Also learn about 3 considerations you should have in mind when designing, planning, and implementing Industrial Ethernet networks.

While Ethernet technology has become widespread, the commercially available Ethernet technologies and category cables we use in our everyday work and personal lives are NOT the same as those being deployed across the world in Industrial settings to power the next generation of 21st Century factories.

Unfortunately, Commercial-grade Ethernet is too often mixed into industrial settings, causing far more detrimental impact to quality, productivity, uptime, and OPEX (Operational Expenditures) than can be recouped from the initial CAPEX (Capital Expenditure) cost savings of commercial cable and components.

By following a few key principles factory networking designers and installers can ensure the right Ethernet technologies for modern industry.

Commercial Ethernet was invented 40+ years ago as the de facto physical layer communication protocol for data transmission between local or wide-area computing devices.

With a standardized method of communication utilizing frames for sending information between devices, Commercial Ethernet’s broad popularity brought to bear high reliability, backward compatibility, and relatively low-cost digital communications that helped enable and revolutionize the Internet.

What Is Industrial Ethernet?

Ethernet shares some similarities, some important differences abound which are critical to the success of a modern industrial plant.

Commercial vs. Industrial Ethernet: What’s Similar?

Commercial Ethernet and Industrial Ethernet are built upon the same basic foundations and share similarities in a few respects:

• Both share some common communications characteristics such as frame sizes and signal levels
• Both use the same general physical layer and media (e.g. hardware) technologies, though as we’ll see later there can also be major differences depending upon the type of industrial application
• Both provide varying data transmission rates from 10 Mbps to 1 Gbps (and beyond), though 100 Mbps is a common speed for industrial applications. Commercial Ethernet is can be found at much faster transmission rates to handle the communication of high bandwidth uses such as movie streaming and video conference, while the amount of data bandwidth needed for sending automation information in a factory is much lower.
• Both use various “categories” of Ethernet cable (e.g. Cat5, Cat 5e, Cat6, Cat6a, Cat7.) depending upon the maximum transmission speed, bandwidth, and other network characteristics.

Commercial vs. Industrial Ethernet: What are the Differences and Why?

First, Industrial Ethernet is used for the mission-critical purposes of maintaining production uptime (and avoiding costly line-down situations), maintaining quality, (and preventing costly waste and rework), and providing a critical control functionality of a modern, networked factory (and its associated automated equipment, instrumentation, and other systems).

Any loss of reliable communications signals can mean a direct and costly impact on an enterprise’s bottom line, and in worse-case situations even result in an unsafe work environment for employees.

3 Considerations when Designing, Planning, and Implementing Industrial Ethernet Networks 

This non-deterministic nature of Commercial Ethernet networks (and its resultant slight communications delays) may be fine for enterprise and other applications such as most data center and office business settings but can be entirely unacceptable in industrial applications where robots, control systems, and other automated equipment depend upon receiving information exactly at the right location, at the right time.

Any loss or delay of data between networked industrial equipment can result in flaws in the production flow as well as a loss of efficiency and quality control.

Industrial applications require the determinism of Industrial Ethernet networks, and each company will need to evaluate their individual needs and determine the optimal Industrial Ethernet protocol solution for their organization and situation.

Once the Industrial Ethernet protocol is determined, the selection of the appropriate Industrial Ethernet cable for EtherNet/IP®, PROFINET®, and EtherCAT® applications can then proceed forward.

To provide a common framework for evaluating physical environmental factors related to Industrial Ethernet networks, various international standards such as TIA1005 and ISO 11801:3 as well as Industrial Ethernet protocol consortiums like the ODVA utilize what is commonly referred to as the M.I.C.E. requirements for Industrial Ethernet cabling systems.

• The “M” indicates the Mechanical environment – cables may be subject to severe physical-mechanical forces, such flexing to different degrees and frequencies, or being crushed (e.g. run over by a forklift).
• The “I” stands for Ingress, which brings attention to Ethernet connectors that need to be able to block the entrance of harmful liquids, dust, and gases from areas where they can cause damage.
• The “C” stands for Chemical or Climate-related impacts such as extremes in temperature, humidity, and the presence of harmful oils (e.g. machine tool coolants) and industrial chemicals (e.g. solvents).
• Lastly, the “E” in M.I.C.E. represents Electromagnetic effects which we will talk about in the next section.

The following are the most common practical considerations to address physical environmental factors in Industrial Ethernet settings:

• Motion: Modern industrial settings are full of motion and movement, from robots to moving assembly lines and gantries, all of which require specialized Industrial Ethernet cabling to withstand these effects. These applications can lead to unique needs for different types of flexing cable capabilities. Many applications can utilize Industrial Ethernet cabling rated for “Stationary” applications, but increasingly factories have applications requiring “Flexible” cabling or even “Continuous Flex” rated Ethernet cable for the most rigorous, always-moving, high flexing cycle situations. Lastly, industrial applications with twisting machinery will require Ethernet cabling designed and tested for “Torsion” In general, manufacturers design and construct cabling with higher numbers of thinner copper conductors (e.g. high copper “strand count”), arrange the conductors in specific patterns and then use specialized jackets (such as Polyurethane) and shielding configurations all to optimize for the type of motion the cable will be subjected to.

• Abrasion: Cables can be subjected to scratching, cutting, and friction when exposed to other moving pieces of equipment. The use of Polyurethane (PUR) or Thermoplastic Elastomer (TPE) jacketing materials instead of PVC provides additional protection to Industrial Ethernet signals in these situations. As one can see, the choice of an Industrial Ethernet cable’s jacket material has major fit-for-purpose implications. The accompanying table provides an overview of the appropriateness of the top 3 Industrial Ethernet cable jacket materials versus the most common physical “stressors” found in industrial environments.
  

  	PVC (Polyvinyl Chloride)	PUR (Polyurethane)	TPE (Thermoplastic Elastomer)
  Heat	Good to Excellent	Excellent	Outstanding
  Oil	Fair	Outstanding	Outstanding
  Low Temp Flex	Poor-Good	Excellent	Outstanding
  Weather	Good to Excellent	Excellent	Outstanding
  Abrasion	Fair-Good	Excellent	Excellent
  Flame	Excellent	Excellent	Outstanding
  Water	Good to Excellent	Good to Excellent	Excellent
  Acid	Good to Excellent	Excellent	Excellent
  Alkali	Good to Excellent	Excellent	Excellent
  Degreaser Solvents	Poor-Fair	Excellent	Excellent

• Zero Halogen, Low Smoke, and Flame Retardant Applications: For applications where a fire is a key concern for your environment, the selection of the appropriate Ethernet cable jacket is of paramount importance. Industrial Ethernet cables that are either Halogen-Free or Low-Smoke-Halogen-Free (LSZH) are constructed of specialized materials to not emit harmful halogen smoke when under fire, which can be extremely harmful to human beings. The most fire-stringent Ethernet cable is designed to meet Flame Retardant and Non-corrosive (FRNC) requirements which make them much less susceptible to burning at all to prevent flame spreading in fire situations. See the table below for comparisons.

  Type	Characteristics
  Halogen-Free	No halogen materials which emit thick toxic and corrosive smoke
  Low Smoke, Zero Halogen (LSZH)	No halogen materials and little smoke
  Flame Retardant and Noncorrosive (FRNC)	No halogen materials, flame retardant

Lastly, Industrial Ethernet switches can differ from their Commercial versions with more robust housings, mountings, and other physical features that are conducive to industrial environments.

Practical Consideration 3:  Electromagnetic Environmental Factors

Today’s industrial plants are a veritable electromagnetic “ocean” inhabited by numerous generators of noise such as large motors, VFD (Variable Frequency) drives, arc welders, induction heaters, ovens, power lines and many more. 

This electromagnetic ocean can drown out our meticulously constructed Industrial Ethernet networks with magnetic, RFI (Radio Frequency Interference), and electrostatic noise if network architects and installers aren’t careful. 

All it takes is one bit of damage to an Ethernet communications packet and a frame error could cause the receiving device to reject the entire packet.

As previously mentioned, international standards providing best practices for Industrial Ethernet via the various “M.I.C.E.” framework where the “E” stands for Electromagnetic noise.

These best practices include the selection and installation of cables and connectors in higher noise industrial environments. For example, the ODVA provides guidance for Ethernet/IP networks with respect to different levels of electrostatic discharge, radiated RF, Conducted RF and magnetic fields. The following are a few practical considerations for Electromagnetic noise in Industrial Ethernet environments:

• Using Proper Grounding Practices for Cable Shielding: The use of shielded Industrial Ethernet cable provides a very effective solution for electromagnetically “noisy” environments but their shields must be properly grounded to perform the shielding function appropriately. Refer to industry-accepted guidelines for cable grounding such as ODVA’s “Ethernet/IP Media Planning and Installation Manual” or IEEE-518-1982 “Guide for the Installation of Electrical Equipment to Minimize Electrical Noise Inputs to Controllers from External Sources” amongst others for detailed procedures. In general, the shield should only be grounded at a single point (the EtherNet/IP recommendation is at the switch end) in order to eliminate the possibility of ground loops, which occur when there is a potential difference between 2 ground points. This secondary current path and its resultant noise will impact the cable’s signal performance.

• Lengths of cable segments. In general, keep each cable run as short as possible. The longer distance a cable segment is the more susceptible it is to signal degradation and external noise effects.
• Excess cabling. If excess cable results from any specific network segment do not coil it up, which can lead to signal degradation, but rather cut and terminate it appropriately per manufacturer and installation guidelines.
• Manufacturer ratings. Always follow manufacturer ratings for critical attributes such as cable bend radius and maximum pull strength. These standards can be difficult to adhere to during a hectic project timeline with many individual installers but these ratings ensure the cable retains its integrity to communicate the Ethernet signals at maximum integrity.

Conclusion