What makes industrial environments so different?
The biggest problems in industrial Ethernet stem from the hazards to which the networks are exposed. Two factors exacerbate these hazards: the lack of climate control and the presence of other electrical equipment. While the network in an office or data center is protected from the elements by air conditioning and shading systems, most industrial environments lack this control. Excessive heat or humidity, for example, can affect the transmission media. Twisted-pair cable, commonly used in office networks, can deteriorate after prolonged exposure to sunlight. Electromagnetic interference (EMI) generated by electrical equipment causes noise that disrupts network traffic. RJ-45 connectors, the backbone of corporate networks, are not designed to operate for extended periods under excessive heat or stress, and their contacts can corrode and lead to label breakage.

The distances over which the signal must be transmitted are another notable difference. Industrial Ethernet cable may require approximately 400 meters in large plants and is located around hazardous areas (machine-to-machine and switch-to-switch). Twisted-pair cable, used in offices, has a maximum distance of 100 meters. Although this specification originated to separate user transmissions and prevent collisions, current distance limitations are a result of electrical transmission.
Network Interface Cards (NICs) have also been developed for distances of up to 100 meters. Beyond this distance, extra power is required, and noise can be generated that interferes with data transmission. Multimode fiber is sufficient for distances up to 2 kilometers. For distances between 2 and 3 kilometers, single-mode fiber optic cable is required. Furthermore, fiber optic cable has its own specific requirements. The diameter of a single-mode fiber is smaller than a red blood cell. Fingerprints or even airborne dust particles can become lodged in the fiber optic termination, causing reflection and inhibiting signal transmission.
Finally, something as basic as electricity can affect an Ethernet installation. Office Ethernet components cannot function in an industrial environment powered by 24 or 48 V. Industrial-grade components will likely be required.

A Difference in the Nature of Work: The Need for Determinism.
In an industrial setting, the nature of the work performed and the functions of the devices are very different from an office network. Lost traffic takes on much greater significance in industrial environments. In many office networks, data loss isn't as problematic, as there are several ways to compensate for lost packets. At the very least, a user can resend a data file that has been corrupted during transmission. If the office network is a bit slow, it's annoying and impacts staff productivity, but work can still be done.
In the industrial world of high-speed production and precise processes, the correct and timely delivery of communications is extremely important. A data packet could contain a warning of overheating or even fire, or a command to activate the cooling system. Corrupted, lost, or untimely packets, whether due to speed or slowness, cause serious consequences: production errors, reduced output, increased waste, and longer downtime. All of this translates into higher costs.
For these reasons, industrial Ethernet must be 'deterministic,' meaning the network must guarantee that an event will occur within a specified timeframe. This is not the norm in corporate environments, and there was a time when this was also not the case in the industrial world. Now it has become a requirement.

Understanding Ethernet Standards and Ratios:
Knowledge of some of the Ethernet standards and ratios that have evolved over the years can help in designing more robust and resilient networks.

Classifying Environmental Conditions with MICE Tables
: To describe the potential environmental conditions in industrial areas, the Telecommunications Infrastructure Association (TIA) has created the 'Mechanical, Ingress, Climatic/Chemical, and Electromagnetic' (MICE) tables. Level 1 describes a typical office environment; Level 2 shows somewhat more adverse conditions; and Level 3 presents a heavy industrial environment.

Approximately 80 percent of environments correspond to the MICE tables, with the exception of only the most extreme or specialized ones. The Mechanical section of each table provides values ​​for shock/impact, vibration, tension, crushing, impact, and bending. Ingress specifies the particle size (dust). The Climate/Chemical section shows values ​​for temperature, humidity, radiation, and liquid and gaseous pollution from the most common industrial contaminants. Finally, the Electromagnetic section provides specific values ​​for electrostatic discharge, radiated and conducted radio frequency (RF), short-circuit voltage, and magnetic field.
The MICE tables do not constitute a set of cabling requirements, but they offer a useful context for evaluating specific environments and selecting compatible systems. It should also be noted that the same cabling may be suitable for several MICE environments. By establishing limits, it is possible to minimize the need for cabling with very high ratios throughout the installation.
Determining the level of protection offered by connectors, devices, and other equipment:
An IP (Ingress Protection) rating indicates the degree of protection offered by the equipment and is always specified with the letters IP followed by two numbers. The first number indicates the level of protection against solid objects, while the second represents the level of water resistance. An IP55 rating, for example, demonstrates that the device offers sufficient protection against dust and water particles without affecting its operation. A higher number, such as IP68, indicates that the device is dustproof and can be submerged in water without adverse effects.
The RJ-45 connector, typically used in patch cables, does not have an IP rating, as it was not designed to offer protection against dust or to be completely waterproof. Ethernet cable for harsh environments will require specially developed RJ-45 connectors with protective sealing or will have to use other types of connectors, such as M-12. With an IP68 rating, M-12 connectors offer the same levels of physical protection against solids and liquids. Pharmaceutical industry applications are a good example of the need not only for connectors with a high IP rating, but also for equipment enclosures with a high IP rating.

Learning from others' examples:
The network.
The biggest mistake made when installing industrial networks is thinking that an office network can be used in a production facility. The variable traffic and addressing schemes of the corporate network should not interfere with the consistent, structured, and less variable nature of a production network. Corporate traffic can slow down production traffic and jeopardize the deterministic nature of the industrial network.
A VLAN (Virtual Local Area Network) is one way to segment network traffic. Corporate and production networks can communicate with each other, but they cannot share each other's "pathways." It's similar to thinking of two highways with a tunnel providing access between them.
The second mistake is trying to save money by purchasing "office-carrier" Ethernet switches. Industrial environments require industrial-rated switches, as they are designed to withstand the rigors of the industrial world and contribute to a more efficient network. In production, it is essential to reliably transfer information from point A to point B. The end result of poor network performance in an office is often reduced performance on user PCs. On the production floor, the difference between a communication that takes four or six seconds could be the difference between high-speed online work and work that doesn't. Or, in a sheet metal plant, it can determine whether the material is cut to the correct length.
The proper flow of information maintains adequate speed and a constant temperature over a distance of approximately 43 meters.

Electrical Signals:
Network devices, such as switches, can be affected by the same problems that affect cabling. Harsh electrical environments can cause transients, outages, and static discharges. Extreme humidity and temperature changes, vibration, and inconsistent or inefficient power delivery can all disrupt signaling. Devices with an appropriate IP rating can mitigate many of these problems.

Infrastructure cabling: protecting cables from exposure to risks and hazards.
In a typical data center, you'll likely find a server with unshielded twisted-pair cables hanging out the back and extending to the ceiling; this is perfectly acceptable. In an industrial environment, however, cables need to be protected with plastic or metal sheathing. It's also acceptable for Ethernet to run along the ceiling in open trays. But when those cables reach the wall or anywhere they might come into contact with water, heat up, or be struck, they require a sheath.
EMI protection also needs to be considered. For example, one machine might be filling bottles while another is packing them into boxes. The Ethernet line needs to be separated and shielded from the EMI field generated by machinery, cables, motors, and transformers. Excessive electronic noise will also interfere with the signals. This often manifests as certain easily recognizable network errors and indicates that the transmitted frame has been corrupted somewhere along the way.
What can be done? Unshielded twisted pair (UTP) cabling is inherently immune to lower levels of EMI. For higher levels, shielded twisted pair (STP – also known as CAT 5) cables are preferable. And for maximum protection,
fiber optic cable, which is immune to EMI, is the best choice.
Using high-rated cable is not the only solution for harsh environments. It must be complemented by a combination of separation, insulation, and strategic planning. For example, where there is a risk of liquid spills, separation is achieved using cable trays, while insulation is provided by metallic jackets that mitigate EMI noise.
When operating in harsh environments, preventative measures such as regularly replacing patch cords and connectors should be taken to avoid downtime. Establishing and documenting the network infrastructure and performing preventative maintenance do not guarantee reliable network operation. Rapid troubleshooting with the appropriate tools is also essential.

Fluke Networks helps you take control of your industrial network.
Network uptime is crucial for profitability and quality. One failure can cause another, resulting in significant losses of time and money. Regardless of your Ethernet adoption stage, Fluke Networks is committed to keeping your network operational at all times. To achieve this, Fluke offers a comprehensive portfolio of ruggedized, user-friendly solutions and tools that meet the needs of any industrial environment, along with the expertise to quickly address everyday challenges.

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Author:
Fluke Networks Technical Department