NMEA 2000 Standard

NMEA 2000 protocol. Next time you are in the market for a new addition to your boats marine electronics package and are looking at the latest offerings you may see the label NMEA 2000 compliant. NMEA 2000 is the latest version of NMEA which is the marine industry standard for the way electronics and marine instruments talk communicate to each other. Previous version of NMEA is the 0183 standard.

There are several benefits of using 2000 compatible equipment for your boats electronics system and they include; easy installation, reduced costs involved with installation and the ability to mix electronic

NMEA 2000
NMEA 2000

manufacturers products to build your perfect electronics system.

Now its important to know that some Companies like Raymarine have their own method of talking to each other. In Raymarine’s case their proprietary method of interfacing is called SeaTalk. If you use only Raymarine then you may not need NMEA. However if you want to add another manufacturers product to your system you will need something like NMEA 2000.

The best thing about NMEA 2000 is that you can mix and match equipment from different manufacturers to build your boats electronics system. The new NMEA 2000 system is based on a single backbone cable that sends messages and data in both directions.

NMEA 2000 also referred to as N2K

NMEA 2000 Network will completely change the way you think about networking. It will finally answer the hard questions of hidden costs, ease of installation, simplicity, configurability and scalability. The NMEA 2000 network is an open true plug and play system, installing is just a matter of plugging in. Subtracting a device from the network is simple; just remove it, the network continues to share data. When new NMEA 2000 certified products are purchased, the owner, boat dealer or electronics dealer will only have to plug the new certified product onto the network. The boat will always be ready for the future. Only NMEA 2000 certified products can communicate with each other. NMEA 2000 can increase your bottom line profitability

The NMEA 2000 Marine Network Standard was developed by various companies in and outside of the industry. More than 40 marine organizations have invested time and resources to create NMEA 2000 based on CAN (Controller Area Network). In addition, other experts outside of the marine industry included, Kvaser AB, Oklahoma State University, Sun Microsystems, and the U.S. Coast Guard Research and Development provided countless hours of support. Today, the standard continues to evolve meeting industry needs by energetic and committed industry professionals collaborating in a structured Working Group. Internationally, the International Electrotechnical Commission is in the process of adopting NMEA 2000 as the network standard for the use on SOLAS class vessels with its standard 61162-3.

Wiki definition 

NMEA 2000 improvements over NMEA 0183

NMEA has a data speed of 250k bits/second, that compares to NMEA 0183 which has only 4.8k bits/second.

How does NMEA 2000 work? it is a multiple talker system which means it can transmit and receive signals simultaneously. This ability to process huge amounts of data enables the single backbone system to work connecting multiple pieces of equipment from many different manufacturers. The NMEA 2000 backbone cable can connect the boats GPS, VHF, radar, Chartplotter, engine, outboard motors, speed and depth transducers.

Backbone cable and drop connectors

The NMEA 2000 system is also called a CAN network (controlled Area network) The cables required to build a NMEA 2000 network are called

NMEA 2000 back bone
NMEA 2000 back bone

DeviceNet cables and come in Mini (8 ampere hrs) and Micro (4 ampere hrs).

These are the basic components showing how easy the connections can be made. The drop connectors are used to connect electronic equipment to the backbone.

Network and System Design

These diagrams shown here courtesy of Maretron show how a NMEA 2000 system is put together.

NMEA 2000 network
NMEA 2000 network

To build a NMEA 2000 network for your boats electronics system should be done with the help of a NMEA qualified technician. This way you can get the right power connections and bacis layout. After that any additions can be easily made.

The NMEA 2000 DeviceNet cable are relatively expensive. However when you consider the labor saved in installation costs and time the cables are worthwhile.

These diagrams shown here courtesy of Maretron show how a NMEA 2000 system is put together.
These diagrams shown here courtesy of Maretron show how a NMEA 2000 system is put together.

 

The elements of a NMEA 2000 system include a backbone cable running the length of the boat, drop cables to connect electronic devices to the system and a power supply from a 12V DC source. Some individual devices can get their power from the system while other larger devices such as Radar need more power than the system can supply.

 

Engine Gateway

NMEA 2000 engine gateway
NMEA 2000 engine gateway

If you want to add engine or outboard data to the NMEA 2000 system that is no problem. NMEA 2000 and J1939 Engine Gateways, can supply engine data to the network which can then be read on a display or PC.

FW Murphys helmview is one example of such a display

Lowrance Engine Gateways

 

NMEA 2000 engine gateway lowrance
NMEA 2000 engine gateway lowrance

 

 

 

Conversion

NMEA 0183 to NMEA 2000

NGW-1 NMEA Gateway
NGW-1 NMEA Gateway

What if I have NMEA 0183 and now want to add a NMEA 2000 GPS or other gadget. Yes it is possible to combine both buses with this product from Actisense.

The Actisense NGW1  NMEA 2000 Gateway is an easy way to link between your boat’s data networks. The NGW-1 makes it possible to convert NMEA 0183 data into NMEA 2000 data and vice-versa.

Using the advanced configuration software it is simple to set up which data items you want translated between the two buses.