Feeding these values in to the volt drop formula we can calculate the voltage drop asвЂ¦. The total backbone length is 10m and the total LEN of the devices on the network is 12. In the following example, we have a typical NMEA 2000 network with the LEN values of each device shown and the lengths of all of the backbone cables. If voltage drop > 1.5V add an additional Power Insertion point (Power Cable) which must be taken to the same 12v DC supply as the other NMEA 2000 Power cables or move the existing power cable to the middle of the NMEA 2000 network backbone so that the volt drop to each end of the network is reduced.Volt Drop = LEN x Backbone Length x 0.006 To calculate voltage drop, use the following formula, which is valid for most NMEA 2000 networksвЂ¦.The longer the cables or the higher the current, the larger the voltage drop and if greater that 1.5V, then data errors can occur.When current flows through the NMEA 2000 backbone and drop cables, a voltage drop occurs resulting in the voltage at one end of the network being different to the voltage at the other end.Add up the LEN values of all devices and make sure the total is less than 60 LEN which equals 3A.The LEN number will be printed on the devices product label (see example below).Every NMEA 2000 certified device, has aВ Load Equivalency Number or вЂњLENвЂќ for short.

It is very important that the total network current is known and that it is less than 3A.Each device on the NMEA 2000 network consumes some current.If the total current is more than the safe current capacity of the NMEA 2000 cabling (3A for all Digital Yacht cables) then the cable could melt or even cause an electrical fire.

The volt drop from one end of the network to the other, must be less than 1.5VДЄ key consideration in any good NMEA 2000 network design, is the total current that the network is consuming.

Total length of all drop cables must be less than 76m.

The NMEA 2000 backbone must be less than 100m.

Maximum number of 50 physical devices on the network.

The NMEA 2000 Supply current must be less than 3A (60 LEN).

The NMEA 2000 Supply voltage must be between 9V and 16V.

The network must be properly terminated only two terminators fitted one at each end of the backbone.

The list below, gives you all of the key NMEA 2000 networking rules that, if followed, will ensure your NMEA 2000 network works correctly. The part number is ZDIGN2KIT and if you want to find out more about the Digital Yacht NMEA 2000 Starter Kit, please click here.Д«elow is a diagram showing how the two NMEA 2000 devices above, can be correctly connected together using the NMEA 2000 Starter Kit.

An NMEA 2000 Starter Kit is a cost effective way to build a small, expandable network.

There is a small cost in setting up the network, but future expansion is very easy.

Some smaller low power devices, like sensors are also powered from the network.

Each device has an NMEA 2000 interface that must be powered from the network.

You cannot just plug two NMEA 2000 devices together with a suitable NMEA 2000 cable вЂ“ they must be connected to a properly constructed NMEA 2000 network. * Note вЂ“ Some manufacturers have created their own вЂњflavoursвЂќ of NMEA 2000 with different connectors and cabling RaymarineвЂ™s вЂњSeaTalkNGвЂќ and SimradвЂ™s вЂњSimNetвЂќ are two examples and both need proprietary adaptor cables to connect to standard NMEA 2000 networks.

NMEA 2000 is a standard set of data messages, protocols and connectors that all NMEA 2000 devices must use*.

NMEA 2000 allows marine electronic devices from different manufacturers to talk to each other.

NMEA 2000 is the marine version of the CAN networks found in every modern car.

It is not the most in-depth technical article on the subject, there are plenty of those online, but it focuses on giving you the core information you need to use the Digital Yacht range of NMEA 2000 cabling products to create or expand your NMEA 2000 network. This guide is for anyone who is new to NMEA 2000 and wants to quickly understand the key issues in building an NMEA 2000 network.

Nmea 2000 network design software