How does NMEA 2000 device certification minimize my installation risk?

All NMEA 2000 certified devices must undergo; a strict certification process before they receive the mark "NMEA 2000 certified", where hardware and software must be tested to check a number of different parameters, from Power to CAN -green interface. Äeven if the price tag onå an uncertified device may look appealing, here are the reasons why you should always use NMEA 2000 certified devices in your boat network.

"The National Marine Electronics Association provides a self-certification tool to help manufacturers test their products during development and before final release. NMEA requires that all devices that provide a NMEA 2000® ; interface must pass the self-certification test before that product can claim to offer NMEA 2000®. This ensures that all NMEA 2000® based devices implement the network protocols correctly. This testing also ensures that the automatic self-configuration capabilities defined by the NMEA 2000® standard are correctly implemented and do not cause or generate problems for other equipment in the network for any reason. . The testing is designed to reveal any flaws or weaknesses in the implementation of the NMEA 2000® protocol and to ensure that all devices from all manufacturers behave as expected. a known and extractable method in the network. This testing does not validate the data or measurements provided by a device, only how it interacts in the network."

https://www.nmea.org/Assets/final_rtcm_2002_white_paper.pdf

The most important point to note is that if the device has NOT passed the certification tool and signed by NMEA, it cannot be marketed as NMEA 2000 certified.The number of products falling into this category seems to have increased dramatically in recent years, attracting a number of as these products are usually cheaper.

Devices that have not been tested and certified may suffer from interoperability issues with the NMEA 2000 network. Address conflicts and power issues Since NMEA 2000 is a CAN BUS network, it is important that all devices communicate with each other correctly to avoid conflicts and data problems.

With non- certified units onå the network, it is not only those who will be affected, they also affect certified devices... For example;

Our NGT-1 NMEA 2000 Gateway is a high priority device that claims to a low source address in the network. Once the device has completed all necessary addressing and interface processes, it will act as a NMEA 2000 to PC gateway.

If a device is introduced in the network that does not follow the address claim procedure and always goes for the highest priority address, it may conflict with NGT-1. At best, this will result in temporary data loss from the NGT-1, but the more likely result is that the other device continues to interfere, resulting in the NGT-1 not working.

Another common scenario with untested and certified devices is the amount of power they draw from the network. All NMEA 2000 certified devices must operate on; 9-16V, and most are designed with a 12V network connection in mind.

There are certain rules that a NMEA 2000 must follow with power draw and how much current it draws from a network. If too much is required of the unit, an independent power supply is required. Using devices that are not tested for this can cause too much power to be drawn from your NMEA 2000 network, causing devices that are close to the outermost parts of the wider network are often shut down or become intermittent.

In summary, the user cannot be sure of that an uncertified product will behave safely and correctly in a NMEA 2000 network. If you are not sure about if a device is certified, there is a complete list of certified devices on NMEA website.