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Full Version: [TG] Axiom Fuel Manger and G/hr - fuel consumption the same for each engine
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I have twin 5.7L MPI engines with Fox Marine engine gateway and Axiom with latest software. When I use the the engines data screen I see each engines RPM values independently. But eh Fuel flow show the same on each side and makes be believe that the fuel flow rate from each engine is being added together and displayed as the sum. Is this correct? Or do I have something configure wrong? Or do I have the option to show summed vs separately?
Hello qbayle,

If the data items you're looking at are Engine Fuel Rate (1) and Engine Fuel Rate (2), this should be what's coming directly from the relevant engine over NMEA2000. If you're seeing a single common value, that's usually because the transmitting device isn't sending correct data. It's not an MFD configuration or setup issue.
This could be that the transmitter is summing, or perhaps is sending two messages with the same engine Instance number (Instance is the first data item in each engine message and tells the receiving device which engine the data applies to, where 0=Port and each subsequent engine is numbered from there.)
Engine RPM is sent in one message (127488, Engine Parameters Rapid Update) whereas fuel flow rate is sent in another (127489, Engine Parameters Dynamic) so it is possible that you could have correct Instance identification in one and not the other.

We can understand what's going on either by doing some practical tests on-boat, or by having the NMEA2000 raw data recorded and sent in to us for analysis:

The simplest on-boat test would be to run Port, observe the fuel-flow rate displayed in each data item, then stop Port and run Starboard, then run both together. You'd expect, of course, to see zeroes or dashes for whichever engine wasn't running, and approximately the same value for each when both are running as when only one is running. If that's not what you see, let us know what results you do get and we can work out what's going on.
Another test would be to look at any of the other data sent in the same message (127489) as fuel flow rate: almost everything engine-related except for RPM, Boost Pressure and Tilt/Trim is sent in 127489, so how do oil pressure/temp, coolant pressure/temp, alternator voltage, torque/load or operating hours look?

On the other hand, the other way would be for someone to look at the raw NMEA2000 data. You can't (yet) record this data with the Axiom display, but many technical dealers will either have a PC interface that can do so, or a Raymarine Lighthouse 2-generation display that can. Either way, if you can get a log-file of the NMEA2000 data, I'd be happy to have a look.

Okay, I will do some testing. I have the engine ID correct, Fox marine setup for me and I have 2 cell phones I can see the data separately there. I also have a lmf-400 unit and can see it separately there. Let me check the data box on the axiom data screen for what value it is pulling because I do not remember even seeing any options that ended with a (1) or (2) after them and I did expect to be able to select which engine I wanted the data from.
Ok, I'll wait to hear what you find.

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