Connecting infrastructure Webcast questions, answers on industrial automation networks
The Internet of Things (loT) for industrial plants is increasing the number and diversity of connections. The "Connecting Infrastructure" Webcast, now archived, discusses how the value of connections increases with use of wireless, mobility, and virtualized services. Answers that didn’t fit into the question-and-answer session cover training, Ethernet network design, future proofing, best practices, and cable types. Webcast presenter, Dan McGrath, solutions manager, industrial automation infrastructure group, Panduit Corp., provides the answers.
Q: What training is available?
Dan McGrath: With the number of Internet protocol (IP) devices in manufacturing increasing, control engineers need skills for designing and/or migrating to a converged Ethernet architecture. Online training from the Industrial IP Advantage organization gives control engineers critical skills for designing a structured, IP-centric industrial network that can reduce implementation time and contribute to long-term operational savings.
Q: When is fiber the best choice for connections between industrial Ethernet switches?
McGrath: Fiber has to be considered whenever longer runs between equipment are encountered, such as longer than the 100-m (328-ft) limit for structured copper cabling, or in cases where the path is subject to electromagnetic interference that might corrupt data. In addition, for the particular question of using fiber between switches, studies by Cisco and Rockwell Automation have found that convergence time (the time taken for the switch to recover from errors) is faster when using optical fiber. Cisco and Rockwell recommend using fiber in resilient rings connecting switches. See the "Cisco – Rockwell Automation Converged Plantwide Ethernet Design and Implementation Guide."
Q: How does a building block approach using integrated or preconfigured systems reduce cost and risks for network deployment?
McGrath: Some of the benefits from using preconfigured systems include: 1) reduced time to design, 2) reduced installation time, 3) assurance that you get a consistent, engineered, repeatable building block that can be deployed at any location.
Q: I like the idea of a staged approach. I think that staging is more cost-effective. Agreed?
McGrath: A staged approach can be cost-effective if longer-term needs are considered so that short-term solutions meeting current needs don’t need to be "rip and replaced." The use of maturity models to consider organizational goals is critical for developing the initial scope. Then use of reference architectures and even design services can help map out a structured plan to be implemented over time.
Q: I believe that the only constant in technology is that standards are made to be improved. How can one propose a major project to a plant manager without giving life expectancy or stability? Financial decisions based on technology are risky since technology changes are measured in months now, rather than years.
McGrath: The idea of future-proofing is always difficult to justify when considering a purchase. One fact that history has shown and continues to forecast is that the amount of data increases with time. Although many of the data rates encountered on the plant floor are relatively slow at end points on the machine, such as 10 Mbit/sec or 100 Mbit/sec, we see these rising, and for this reason would always recommend the use of a higher category of structured cabling to accommodate future data rate increases.
Q: Who established the best practices?
McGrath: "Best practices" is a short-hand term often used in presentations, but it’s a good question as to what it really means. Panduit, with our partners Rockwell Automation and Cisco, stress validation and testing in support of best practices for Converged Plantwide Ethernet. At Panduit, we take pride in the depth of validation used. Lab testing, application research at customer sites, and standards bodies alignment are all key ways to ensure that the design and deployment recommendations Panduit makes will offer sustainable value.
Q: We need to look at the systems as a process, with many steps in a logical sequence. Agreed?
McGrath: One of the keys to the Cisco Rockwell Converged Plantwide Ethernet model is recognizing that the plant floor can be divided into zones that map physically to a structured cabling approach and incorporate preconfigured solutions, such as the Industrial Data Frame (IDF), a plant-floor-based solution that incorporates Layer 2 and Layer 3 switching and preconfigured zone enclosures that incorporate Layer 2 switching to feed control panels in the manufacturing zone.
Q: Is your M12 D-Coded Ethernet cable certified for Gigabit Ethernet? How many poles/contacts does this connector have as Gigabit Ethernet required eight conductors (poles/contacts)?
McGrath: The M12 D-code cabling (using two pair cable) would only be capable of supporting up to 100 Mbit/sec data rates. The M12 X-code connector has eight pins and when used with Category 5e 4 twisted pair copper cable or higher, then the cable assembly is capable of supporting Gigabit operation.
Q: How do I get a copy of Microsoft Visio templates and diagrams for consultant specifications for system integration?
McGrath: Panduit has many design tools, including Visio templates accessible through our Website. Also consider Panduit advisory services and training that can jump start system integration (SI) network design capabilities.
Q: What types of fiber are suggested to future-proof installations? Should I install a mix of both multimode (MM) and single-mode (SM) cable? Distances are all less 2,000 ft.
McGrath: Single-mode fiber is capable of supporting 10 Gigabit/sec data rates over channels of up to a length of 10 km (6.2 miles) when using the right transceivers. Multimode OM3 and OM4 fiber supports this data rate up to 300 m (984 ft) and 550 m (1,640 ft), respectively. The question of whether to use a combination of fiber types or just choosing one, such as single-mode fiber for all channels, is often a choice of economics (SM fiber transceivers are more expensive than MM types) weighed against the administration difficulties that often arise years after initial installation of mixed cabling types.
Q: Do you see a value in redundant Ethernet radio systems instead of longer runs of fiber, and/or a secondary path?
McGrath: This is probably a choice between economics and the difficulty of installing redundant fiber. If there are existing pathways, then a fiber option can be considered. If the main and redundant fiber is laid in the same pathway, then an element of the redundancy effectiveness is lost. For example, severe damage to the pathway will likely result in broken main and redundant fibers leading to downtime.
Q: Would I see a lag when using CAT 5 cabling versus something faster?
McGrath: The term "lag" can have a number of specific meanings. There would not be a significant time delay, as an example of lag, between using a Category 5e cable versus a Category 6 cable. From an alternative viewpoint, different category cabling is needed to support different data rates. Category 5e cable can support up to 1 Gbit/sec data rates, whereas Category 6A copper cabling is needed to support 10 Gbit/sec data rates over the full 100-m (328-ft) channel defined in TIA-568 series of standards.
– Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering, firstname.lastname@example.org.
- loT for industrial plants means more connections.
- A "Connecting Infrastructure" Webcast, now archived, discussed how use of wireless, mobility, and virtualized services dramatically increase the value of the connections.
- More answers are available on training, Ethernet network design, future proofing, best practices, and cable types.
Is your plant automation network ready for the Industrial Internet of Things (IIoT) and the resulting productivity it will bring?