How does NMEA 2000 device certification minimize my risk with installation?

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® vda that it offers NMEA 2000® 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 not for any reason cause or generates problems for other equipment in the network. 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 the point to note is that if the device has NOT been through 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 dropped dramatically latest, which attracts a number of drivers as these products are usually cheaper.

Units that do not have tested and certified can suffer from interoperability problems with the NMEA 2000 network. These can occur in various ways, such as cold address conflicts and power issues. As NMEA 2000 is a CAN BUS network It is important that all units communicate with each other correctly to avoid conflicts and data problems.

With non-certified devices på 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 which does not follow the address application procedure and which always 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 quantity current 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 smaller network are often shut off 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.