[CA] [CA11] Ground log on NMEA output

[[email protected]]

I am wanting to capture the Ground log reading over my NMEA network in order to enter it into a logging application.
The sentence I want is VLW which is described on the NMEA set up screen of the es98 as ‘Dual ground/water distance’

The sentence that is output is $VWVLW,4946.49,N,4946.49,N*4C.

The first number is the Log as recorded by the transducer and is correct. The second number I would expect to be the Ground log but it is showing the same as the first number and is incorrect.

Can anyone help or advise me on this?

[Chuck - Raymarine - Moderator]

Welcome to the Raymarine Forum Tim,

The first number is total cumulative thru water distance (Log). The second number is cumulative thru water distance since last reset (Trip). What model of MFD were these NMEA 0183 sentences produced by?

[[email protected]]

Thanks for the reply. This was produced on an es98. It seems the description of the sentence on the es98 is misleading as it definitely states ‘Dual ground/water distance’

[Chuck - Raymarine - Moderator]

Tim,

The format for the VLW sentence follows:

$xxVLW,DATA_TOTAL_WATER_DISTANCE_NM,N,DATA_TRIP_WATER_DISTANCE_NM,N,DATA_TOTAL_G​ROUND_DISTANCE_NM,N,DATA_TRIP_GROUND_DISTANCE_NM,N*hh<0D><0A>

The values reported are indeed as stated within my initial response. Fields which are not populated will be left blank. On my own system running LHII v19.03, the VLW sentence is not populating the ground log and ground trip distances. The transmitted sentences appear as follows:
$VWVLW,0.0,N,0.0,N,,,,*7C .... note the comma delimited fields are not populated for the ground data values.

[[email protected]]

Thanks for the clarification Chuck. I’m going to,post a note in the product suggestions forum that the Raymarine description of that sentence is changed to remove the term ‘Ground log’.
Thanks again.

[Chuck - Raymarine - Moderator]

You're welcome.