until you
know all about NMEA 2000. (NMEA is pronounced “neema”)
I recently attended an NMEA 2000 seminar and
believe me, you need to know lots before you buy
any electronic devices.
In the Past
As most of us know, adding
electronics to older boats meant miles of
spaghetti wiring around your helm and to each of
your electronics - and they only worked together
if they were the same brand.
Each unit required a pair
of wires running back to the power and ground
source plus several other cables that carried
data from transducers and senders. Old
electronics could not share data
from manufacturer to manufacturer and in many
cases, not share from model to model. Plugs were
not interchangeable and wire
color coding varied and
language was different. Displays were
painfully slow to redraw. All
these independent units pulled a lot of power
from your batteries. Sound familiar?
Spaghetti Wiring Under Helm
Now NMEA 2000
Now, at last,
there is standardization. All the major
electronics manufacturers and motor
manufacturers have developed this new
standardized system to be used universally by
all of them. Now there is a single data
language, wiring color code, cabling, connectors
and plugs. This new CAN (Control Area
Network) is instantaneous—called “real
time control”, so it’s much, much
quicker than before and requires less power.
The new system is
NMEA 2000. It’s a new standardized
network system that allows you to add new
components to your boat over time or all at once
all on one cable. All units can
communicate with each other, even if
they are different brands from different
manufacturers.
Before purchasing new
electronics for your boat this spring or summer,
check to verify that each is “NMEA 2000”
certified compatible—National Marine Electronics
Association.
How it Works
Think of how the
electrical suppliers set up a trade show. They
start by running a cable along the back of a
long row of 10’ x 10’ booths. The cable has
electrical outlets installed at set intervals.
Each booth that needs power, simply plugs in
their individual power bars and cords. This
setup is cleaner, neater, saves hundreds of feet
of extension cords running from each booth along
the wall all the way back to the power
source/panel box. It’s not only neater, more
efficient and uses far less wire, it is also
safer and saves power.
The backbone of the new
NMEA2000 network is a cable that comes with a
series of “T” connectors that each unit connects
to for power, ground and data transmitting. Say
goodbye to the miles of spaghetti wire around
your helm required for the old system that dates
back to 1983.
Backbone with "T"
Connectors & Drop Cables to Electronics
Instead of outlets for
plugging into our Trade Show example, the
NMEA2000 cable utilizes standardized “T”
connectors for a more permanent connection than
an electrical plug and outlet. The standardized
cable with standardized colored wire is
available with a series of connection points
i.e., “T” Connectors.
"T" Connector
Each piece of electronics
is simply plugged into the cable
with standardized waterproof connectors and the
required length of “drop cable” from the
backbone cable. If required, extra “T”
connectors can be added anywhere into the cable.
The system does not require a central network
controller, so it is multi-mastered.
Equipment is designed to share both data and
commands with other compatible equipment over
this single cable or channel. You just add units
from various manufacturers or all the same—your
choice. It’s like a building block process that
can grow as and when you want.
Data from the newer
electronically controlled outboard and
sterndrive motors can be shown on the new
multi-function display monitors.
Drop Cable
Additional sensors
can be added for high water, CO, etc. Just plug
these sensors into the cable.
Some new boat and yacht
builders are including and utilizing the
NMEA2000 network cable for connecting gauges,
instrumentation, plus standard and optional
electronics at the factory, anytime at the
dealership and later at the owner’s leisure.
Newer models of marine
electronics that are NMEA 2000 compatible from
Furuno, Garmin, Lowrance, Raymarine, Simrad and
many, many others can be connected to the same
network and utilize data from each other.
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System Diagram |
This is the latest
standard for serial data networking for marine
electronic devices both for navigation and radio
communications that meets global safety
requirements.
Technically speaking, the
NMEA 2000 is a bi-directional
multi-transmitter/multi-receiver instrument
network to interconnect electronic equipment.
The connectors and cables used are compatible
forming the controller area network, which
permits a versatile system to be established
with a minimum of effort and at a reasonable
cost.
The Benefits
The benefits to you, the
boater, are that marine electronic devices from
different manufacturers can communicate with
each other and operate efficiently and safely
through a single standardized cable. Equipment
built to NMEA 2000 standards can share data and
commands on your boat’s network. You can make
choices of the products that you want on your
network from various sources and add them when
you want to. They are also easy to disconnect
and remove for repair or for a technician to
connect up a laptop to troubleshoot a problem.
Before you Buy
If you are in the
market for electronics this year, check to make
sure the unit is NMEA 2000 compatible. There is
no sense spending money on old technology.
If you do upgrade to the
new NMEA 2000 Cable, you can get an AT-10 made
by Simrad that is an NMEA 2000 to 0183 converter
allowing you to interconnect some older products
with the new NMEA 2000. This allows you to
continue using your old products as you slowly
upgrade to the newer products.
For some recent
electronics that were manufactured prior to the
NMEA 2000 standardization, check your model with
its manufacturer regarding convertibility.
Even if you don’t
upgrade your old system with a new NMEA 2000
Cable, a new NMEA 2000 device will work in
parallel to (but not with) your old system. You
can use it, but it won’t talk to your old
system.
When you get a new boat
that has a NMEA 2000 cable, you can just take
your NMEA 2000 compatible electronics with you
and plug them in if you want
to.........................Doug
Dawson |
