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Fuel flowmeters with NMEA2000 on sea and river vessels

The installation of Eurosens Direct/Delta CAN on sea and river vessels is more preferable as it excludes the wave influence on fluctuating fuel level data. The fuel flowmeter will measure the real fuel consumption.
Eurosens Direct/Delta CAN can be used for onboard fuel consumption data display. There is no need for any additional display, as we can connect the fuel flowmeter to an onboard vessel display (also known as a fishfinder, chartplotter or MFD — multifunctional display) using NMEA2000 interface.

The first step in front axle calibration

NMEA2000 is a standard CAN bus used for a display-sensor communication on ships and yachts. It is a special marine protocol allowing easy and safe connection of various devices in a plug-and-play format. 

NMEA2000 protocol part is based on J1939 ‘automotive’ specification, but has certain additional messages crucial for marine application:

  • Latitude and longitude coordinates;
  • The state of the navigation receiver;
  • Control commands for the autopilot;
  • Waypoints;
  • Wind sensor messages;
  • Engine telemetry;
  • Findfisher and echolocation data;
  • Other specific data.

Besides the standard PGN J1939 and the transport protocol of J1939, the data may be sent via a Fast Packet data transfer, that is an alternative way of sending messages more than 8 bytes long.

Let’s move on to the fuel flowmeter installation part.

System integrators usually need to install the fuel flowmeter in such a way that:

1) NME2000 Dashboard (MFD, fishfinder) could support fuel meter and display fuel data.

2) The fuel flowmeter could be connected to the GPS tracker at the same time.

To cope with the first task, the fuel flowmeter must support fuel consumption data output according NMEA2000. Eurosens Direct/Delta CAN supports it and sends two identifiers: PGN 127489 (a package containing instant fuel consumption) and PGN 127497 (a package with a cumulative fuel volume consumed by the engine).

Unlike J1939, NMEA2000 network products have to “advertise” themselves, otherwise they will be invisible for the vessel on-board display.

Pay attention, that one NMEA2000 display can show the data from multiple engines. That’s why the fuel flowmeter settings should have not only the addresses in NMEA2000 network but also the engine number to which the addresses refer.

Check the example below with the operation of NMEA2000 display connected to two Eurosens fuel flowmeters.

NMEA2000 standard also describes two connector types, easily distinguishable:

NMEA2000 network structure includes the backbone bus and the devices connected to it via T-connectors. The bus has the termination plugs at both ends. As you can see, the only difference of NMEA2000 from a vehicle CAN bus is the need for a T-connector to add a new device.
NMEA2000 network structure

Mechatronics guarantees safe NMEA2000 connection with Eurosens cables and T-connectors (type – Micro). 

NMEA2000 T-connector (Micro)

To cope with the second task, a GPS-tracker connection, we’ll also use Eurosens T-cables.
A GPS tracker will be connected to NMEA2000 network via T-cables. Thus, a ship-owner will receive remotely the data on fuel consumption as well as other telematic parameters.
In this case, an extended configuration of CAN messages is required to read the “unusual” for CAN J1939 identifiers PGN 127489 (message with instant fuel consumption) and PGN 127497 (message with a cumulative fuel volume).