In some environments, networking products are placed in clean air conditioned offices, where installers often give less thought to hardening characteristics of switches, routers, and the cables used to connect them. But, other environments are less “pristine”. Here, industrial communications and control networks are expected to operate consistently and reliably under extreme conditions, such as electromagnetic interference (EMI), high operating temperatures, ambient outdoor temperatures, power/voltage fluctuations, machine vibration, mechanical hazards and more.
Industrial facilities present a very different reality. Here, many if not most cables, connectors, switches, and active network components are integral to machine automation, instrumentation and control systems, which places them in harsh and potentially hazardous situations. Even the best Commercial-Off-The-Shelf (COTS) Ethernet systems are not made to handle such conditions over time. Rugged conditions call for ruggedized cables and only industrial grade Ethernet system components are built tough enough to withstand the hazards and risks they are exposed to day after day.
Ethernet equipment and cabling often must withstand the following environmental conditions:
- Temperature Extremes. Extreme cold can make COTS cables stiff and brittle, while elevated temperatures can degrade the plastic used in the cables’ construction and cause an increase in attenuation. Industrial-grade cables are available that will operate in a wider temperature range (-40°C to +85°C) than commercial cables (0°C to +60°C). Commercial-grade hardware (i.e. switches, routers, terminal servers) is designed to operate from 0°C to +40°C, while industrial Ethernet hardware can operate efficiently from 0°C to +60°C — extendable to -40°C to +85°C (conformal coating also available for humid/moist applications).
- Chemical Exposure. Oils, solvents, chemicals and cleaning solutions can soak into COTS cables, especially under heat, causing the cable jacket to swell and lose mechanical strength. On the hardware side, corrosive chemicals can damage the electronics in commercial switches, whereas ruggedized industrial switches are securely sealed to prevent ingress of these substances.
- Humidity Levels of up to 99 percent can be accommodated by industrial-grade switches, which can also be sealed to meet IP67 standards.
- UV Radiation Exposure can cause COTS cable jackets to decompose at an accelerated rate, compromising mechanical strength and electrical performance.
- Physical Hazards. The factory floor holds many mechanical risks, especially for machine automation cables and connectors. Excessive machine movement or vibration can result in cables being pulled or stretched with excessive force, which can create imbalance between the pairs, degrade electrical performance, and increase susceptibility to ambient EMI/RFI. Plant floor vehicles, such as forklifts and moving carts, can accidentally run over cables, causing abrasion, crushing or cut-through.
Even well-made, properly installed COTS Ethernet components are not constructed to survive these kinds of hazards. Only hardened, industrial-grade components are robust enough to withstand the environmental challenges present every day in industrial settings. For mission critical industrial networking and control applications, downtime is not an option.
What are your thoughts on hardened networking equipment?
Come visit part two of “When Do You Need an Industrial Ethernet Solution” with access to a detailed Belden paper on the subject.