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National Marine National Marine Electronics AssociationElectronics Association
Your Boat Show 2009 Your Boat Show 2009
NMEA 2000® NetworkInteroperability
& Interconnectivity
A Primer
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
National Marine Electronics AssociationServing the Marine Electronics Industry Worldwide
Operational Safety is Our Highest Priority
Global Non-Profit marine industry member organization• Technical dealers, manufacturers, distributors, sales reps,
retailers, associate members
Has provided product standards since late 1970’s
Best known for NMEA 0183 (Communications Interface Protocol)
• Dedicated to serve the public interest• Facilitate the public interest in the interconnection and
interchangeability of equipment
• Minimize misunderstanding and confusion between manufacturers
• Assist purchasers in selecting compatible equipment
• Publisher of the Marine Electronics Journal
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
• Industry Educational Programs for Dealers• MEI – Marine Electronics Installer (Basic Program)• AMEI - Advanced Marine Electronics Installer• CMET - Certified Marine Electronics Technician• NMEA 2000 Technical Instruction
• Cooperates with North American organizations such as ABYC and NMMA
• Coordinates and Maintains Worldwide Standards
• Committees such as IEC (International Electrotechnical Commission), SAE (Society of Automotive Engineers)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
Popular Communication Protocols on Boats• NMEA 0183 most known for marine electronics
• Point to point communication, low speed
• Ethernet • Most common, no marine industry standard, high speed, high
bandwith mostly used for images
• Proprietary Networks• Closed systems with no integration of other manufacturers
products
• NMEA 2000 • Built on Controller Area Network (CAN)• CAN used for real time controller • Used in automotive and robotic industries
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 0183 Communications
• Introduced in 1983
• Single talker, multiple listener• NMEA 0183 not a network (point to point communication)
• Can result in very complex wiring systems• Operates at 4.8 kilobits/sec
• Delivers 6-8 messages (sentences)/sec• Terrific for simpler applications• Device to device connectivity
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
GPS
(talker)
"A"
"B"
Shield"A"
"B"
Shield
(listener)
RADAR
(listener)
Chart Plotter
(talker)
To otherdevices
NMEA 0183 Simplified Interface Circuit
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 0183 Shortcomings• Communication speed is 4,800 baud or bits per second
• Highest speed for 0183 is 38,400 baud
• A compass may output heading message ten times per second, rate of turn 4 times per second, and vessel attitude once per second
• NMEA 0183 simply was not designed to handle the current volume of traffic nor the integration of devices that customers want
• Although NMEA 0183 is a communications standard, no certification process for products
• Standard is loosely implemented leading to many interoperability issues (manufacturer A won’t talk to manufacturer B equipment)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009 NMEA 0183 Shortcomings
• Cable and connectors were not specified as part of the NMEA 0183 Standard
• Plug-n-play very difficult as each manufacturer uses different plugs and connectors
• No standardization of wire color coding
• Ambiguities within NMEA 0183 Standard• For instance: Heading can be transmitted and interpreted in
one of several different messages leading to interoperability problems between different manufacturers’ equipment.
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
Ethernet• Ethernet typically used for large data transfers
• Examples may include radar images, chart maps, weather overlay information, and echo sounder images
• No marine industry Ethernet standard• Each implementation uses proprietary messaging which means
data can not be exchanged across product lines• Ethernet not typically used for industry as real time
control interface • (i.e., automotive and factory automation industries use
Controller Area Network or CAN)• CAN Technology is more time determinate than
Ethernet allowing critical messages to always get through
• (i.e., steering, throttle, and other safety critical data must get through in a timely fashion)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
Why NMEA 2000 NMEA 0183 point-to-point communication requiring
complex wiring systems
NMEA 0183 is not a network
NMEA 0183 lacks bandwidth
NMEA 0183 does not specify physical layer (cable/connectors) making plug-n-pay difficult
NMEA 0183 has no certification process
Ethernet protocols tend to be used for data intensive applications and not real time control applications
NMEA 2000 Standard
“Open” Network System Based on CAN (Controller Area Network)
Co-created by industry partnerships of more than 40 diverse organizations
• Academia – Kansas and Oklahoma State • Networking and Computer Industry• U.S. Coast Guard Research and Development
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
What is CAN (Controller Area Network)
• (Controller Area Network) CAN• Develop by Intel and Bosch in 1983• Used in control processes for industrial applications• Used in automotive and factory automation• Proven robust error free protocol
• Bit arbitration transmission
• Message prioritization scheme• Critical messages always get thru
• Determinate messaging
CAN vs. EthernetCAN vs. EthernetController Area Network Ethernet
CSMA/BA - Carrier Sense Multiple Access with Bit-wise Arbitration. Arbitration Loser Ceases Transmission Immediately – No Data Is Lost
CSMA/CD – Carrier Sense Multiple Access with Collision Detection. Collisions Detected 13 to 130 Bits After Collision – Data Is Irretrievable
Bandwidth Limited by Bit-wise Arbitration – 250 Kbps @ 200 Meters
Large Bandwidth – 10 Mbps and Higher @ 100 Meters
Network Frames Limited to 8 Bytes Network Frames Reach 1500 Bytes and Higher
Multiple Error Checks on All Frames by All Devices, Errors Flagged at End of Each Frame
Error Detection Occurs at Receiver Only after Entire Message Is Transmitted
Structured Error Containment Disconnects Nodes Causing Errors
Jabbering Nodes Continue Until Physically Disconnected Or Shut-down
Deterministic Throughout Entire Bandwidth – High Priority Data Always Get Through In A Known Time Period
May Seem Deterministic At Low Utilization, But High Priority Messages Can Be Significantly Delayed By Large Low Priority Messages
NMEA 2000 Standard
• Marine electronics and electrical companies openly collaborated
• 1996 Beta Tested by the Marine Industry• 12 Marine Electronic Manufacturers and the U.S. Coast Guard
under the Guidance of NMEA (1996)
• Furuno, JRC, Litton Marine, Navionics, Northstar, Raymarine, Simrad, Teleflex, Trimble, Wood Freeman
• Kvaser and Vector Can Tech (CAN Companies)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000 Standard
• A true “open” network industry standard where data is shared among disparate companies’ products
• Accommodate real time control and status information
• Standardized physical layer (cable and connectors)
• Product certification to reduce or eliminate interoperability issues
• Time determinate so critical messages get through
NMEA 2000 Standard
• Complete network protocol• True Industry Solid, Robust, Proven, Open Standard
for Marine Electronics, Engines, Electrical and Other Data
• Bandwidth protection scheme Mission critical data always gets through Every message
• Has a pre-defined default priority• Pre-defined default output frequency
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000 Standard• Multi-Talker + Multi-Listener • Multi-Master, No single controller• 250Kbits/sec (50 times faster than 0183)• Up to 200 meter length• 50 Physical nodes
• 252 functional nodes• Drive by wire
• Real time control and status information• Autopilot control
• Navigation information• Vessel monitoring• Electrical system control and status
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000 Standard
• Different Manufacturers products all communicating on one Open network
• Adding a device – Simply “Plug In”• Subtracting a device – Simply “Unplug”• NMEA 2000 certified products
• Provides level of assurance that products will talk to each other
• Commercially viable since 1999• Under different brand names such as,
• Magic Bus by Teleflex• Simnet by Simrad• LowranceNet by Lowrance
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000 Standard Simple Topology
NMEA 2000 Certified Products• Products Must Meet Strict Certification
• Assure products meet the Standard• Assure products behave properly and predictably on the
network • NMEA certifies all tests results• More than 40 manual tests• 61 automated tests within 25 Major Functional
areas• Look for the NMEA 2000 Logo
for Certified Products• Go to www.nmea.org
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
The Physical Layer (Cables and Connectors)• Mandates a Physical Layer
• Standard connectors• Keyed screw-on for correct polarity• Mandatory pull strength requirement • Simplifies installation• Shielded cables• RF immunity• Waterproof (IP 67)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
The Physical Layer (Cables and Connectors)•Mandates a Physical Layer
Standard cable• Network power and data shared on one single cable• Robust proven cables and connector system• Reduction in total wire needed (Significant cost and
weight reduction)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
The Physical Layer (Cables and Connectors)
Heavy Cable Light Cable
Signal Wire Gauge 18 AWG 24 AWG
Power Wire Gauge 16 AWG 22 AWG
Power Wire Resistance
1.34 ohms per 100 meters
5.40 ohms per 100 meters
Power Capacity 8 Amps 3 Amps
The Physical Layer (Cables and Connectors)
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
Photos Courtesy Molex Inc. Photos Courtesy Maretron LLC
Backbone Connection
Drop Connection
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
Typical Tee
TrunkTerminationResistor
Engine Monitor
GPS
Compass
Battery
Display
DepthTransducer
TrunkTerminationResistor
SpeedTransducer
Laptop
Trunk Line
Drop Line
Tee Connector
This illustration is for concept only and should not be used for planning or engineering purposes.
NMEA 2000NMEA 2000Building a BoatBuilding a Boat
Giving You What You Want
• Customization and integration of products
• NMEA 2000 Certified Products provide choices
• No need to be locked in with One Vendor
• One manufacturer does not need to “Own” the Boat
• Giving you the best of class
• NMEA 2000 gives you the flexibility today & tomorrow
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
“NMEA 2000 really works, and it’s going to make boating better. Simplicity, redundancy, multi manufacturer flexibility—my first hands-on experience with NMEA 2000 was, as we say up here in Maine, a corker!” - Ben Ellison, Power and Motor Yacht, Panbo
“The NMEA, with its NMEA 2000 protocol and corresponding 'physical layer', is in the forefront of this revolution, and playing a powerful leadership role.” - Nigel Calder, Independent Author
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009
NMEA 2000 The Industry Networking Standard
• Open• Industry Collaboration
• Product Integration• Robust/Proven
www.nmea.org
NMEA 2000NMEA 2000Seattle Boat Show 2009 Seattle Boat Show 2009