The backbone of connectivityPosted on Written by Kurt Krutsch
National Marine Electronics Association 2000, or N2K standards, are steadily gaining traction as high-bandwidth products transition into marine vessels. Defining an economical data-networking system utilizing a Controller Area Network-based integrated circuit, N2K has helped usher in integrated onboard connectivity.
Accelerated by a convergence of technologies pioneered in other harsh-duty environments, NMEA-certified cable assemblies have become a standard for networking marine electronics. A single backbone cable links vessel engines, navigation, control, power distribution, mechanical and monitoring systems together.
The robust CANbus architecture allows multiple electronic systems to be connected on a common channel for data sharing. By eliminating a traditional daisy chain configuration, plug-and-play equipment can be added or removed while the backbone remains intact and operational.
N2K also established the industry’s first certification program to ensure the compatibility of recreational marine electronics. To date, more than 500 products are N2K-certified. Despite broad adoption, there remain aftermarket suppliers offering non-compliant components. For manufacturers, service technicians and DIY owners, it is important to choose an experienced manufacturer providing N2K-certified products approved for marine vessels.
Designing the connected boat
Modern boat buyers are accustomed to on-demand 24/7 device connectivity. Raising the bar on boating performance, safety, communications, convenience and comfort makes good business sense. Following the lead of automotive OEMs, boatbuilders are strategically incorporating proven electronics to enhance functionality, heighten appeal and competitively brand their lines.
Conveniences commonly found in homes and cars are migrating onto watercraft, including security cameras, infotainment and connectivity for mobile laptops, netbooks and smartphones. As markets expand for integrated satellite systems and Ethernet, so, too, will demand for onboard apps, controls and connectivity. Reliable onboard connectivity translates into better diagnostics, simplified maintenance and actionable intelligence for boat operators.
Designing the “connected” boat presents unique power and network challenges, including onboard data management, space constraints and electrical voltage grounding and regulation. The electrical platform must meet stringent specifications. Cost, compatibility, electrical voltage spikes and onboard signal integrity are important issues in marine engineering.
The serviceable life of marine devices can span a decade or more, so product safety and longevity must be priority considerations. For manufacturers that warranty vessels, reliability is a top priority in component design.
Leading OEMs are adapting technologies from other industries for rugged marine applications. Powerful cross-technologies can provide scalable, flexible and economical platforms for watercraft. An array of cable and connector assemblies and onboard power and networking solutions have been tested and validated in demanding environments.
From sealed quick disconnects to multi-conductor bulkhead connectors, a range of harsh-duty cabling products are N2K-certified to handle life at sea. Certified IP-rated connections help ensure that navigation systems, bilge pumps, fishfinders, hot water heaters, high-speed Ethernet and other onboard systems withstand extreme vibrations, temperatures and saltwater exposure.
Even as N2K standards continue to be refined, the era of the connected boat has arrived. There is no question that the biggest market shift is to networked products. A comprehensive array of open standard cable assemblies, connectors, terminators and power products exists to support N2K systems in engine controls, instrumentation panels, navigation equipment, power steering, body electronic modules, dockside charging and other marine applications.
“Mini” cables are standard for thick backbones and “micro” is the version for thin backbones on marine vessels. Based on industrial DeviceNet cables, micro- and mini- cable assemblies provide flexible design routing, plus space and weight savings, without sacrificing strength and performance.
Molex N2K-certified cables are vibration and water-resistant, with non-metallic, nickel-plated brass and stainless steel epoxy-sealed receptacle shells to improve reliability in corrosive environments. Assemblies are equipped with high-strength cable crimp requiring 35 to 50 pounds of pullout force to prevent accidental unmating. Given the risk of water ingress, onboard power connectors typically require a first-mate ground circuit.
The CANbus-based network works well for lower-bandwidth data communication, but Ethernet serves better for higher-bandwidth instruments. Network connections should be able to be quickly connected and disconnected in situ. From a maintenance perspective, it pays to standardize. At half the footprint of RJ45 connectors, sealed M12 connectors are a standard in other industries and increasingly popular in marine applications.
Seasoned boat owners and manufacturers recognize the complexities of marine electronics system design. About 70 to 80 percent of network failures occur as a result of a mechanical failure involving cabling and connectors. In harsh, heavy vibration conditions, electronic components are at a higher risk of being jarred loose or exposed to corrosive salt, lubricants and other chemicals, which can lead to hours of diagnostic activity chasing down network problems.
Onboard safety and enjoyment relies on dependable products that perform unfailingly. But complexity management is a design essential for better performance and faster installation and to eliminate complexity that can lead to costly assembly and maintenance. The right integrated technologies pay dividends in performance, reliability and longevity. n
Kurt Krutsch is product marketing manager for Industrial Division-Marine at Illinois-based Molex. A single-source provider for marine connectivity, Molex delivers proven power and signal solutions, including marine fiber optics, Ethernet and CAN cables and power connectors. Molex is a member of the American Boat and Yacht Council, the National Marine Manufacturers Association and the National Marine Electronics Association. Currently serving on the NMEA subcommittee working to develop “OneNet” Ethernet connectivity standards for marine electronics, Molex was instrumental in the development of the NMEA2000 connector standards the marine industry enjoys today. For more information please visit www.molex.com or contact a Molex distributor of marine solutions: www.molex.com/contact/MolexDistributor.html.
This article originally appeared in the September 2014 issue.