national marine electronics association your boat show 2009 nmea 2000 ® network interoperability...

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



• 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)


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 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


GPS

(talker)

"A"

"B"

Shield"A"

"B"

Shield

(listener)

RADAR

(listener)

Chart Plotter

(talker)

To otherdevices

NMEA 0183 Simplified Interface Circuit


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.


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)


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



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 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 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 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 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


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)


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)



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)


Photos Courtesy Molex Inc. Photos Courtesy Maretron LLC

Backbone Connection

Drop Connection


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 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 2000 The Industry Networking Standard

• Open• Industry Collaboration

• Product Integration• Robust/Proven

www.nmea.org


national marine electronics association your boat show 2009 nmea 2000 ® network interoperability...

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