I didn't say nor infer that. OpenCPN
functions perfectly well as the only chartplotter
It translates GPS data and put them to the Dashboard, or is a separate plugin in a separate window?[
GPS Odometer is a separate plugin
with its own UI and options for resetting the trip log. Others and myself have provided links to the GPS Odometer manual.
I don't imagine any chartplotter generates the log and sum log data, either 2000 or 0183. By definition, the data is through water, and AFAIK all speed though water knot meters will generate it as part of their function.
Incorrect. Most speed logs
have no mechanism to measure time so they are incapable of calculating the distance travelled. For example if you refer to the manual for the speed log that is installed on my vessel, a Garmin GST 43
, you will note that it does not generate PGN 128275.
As I stated before, some chartplotters and instrument displays do calculate sum and trip logs
and others do not. Those that do may be configured to use distance travelled through water (obtained from a speed log) or distance travelled over ground (from GPS position data).
OpenCPN, on its own does not calculate sum and trip logs. The Dashboard only displays sum and trip log data for distances travelled through the water from data generated by other devices.
On the other hand the GPS Odometer plugin does calculate and display sum and trip logs derived from GPS Poosition data.
Note for Lennart (developer for GPS Odometer), perhaps add a "PushNMEASentence" API call with a generated VLW sentence, so that the Dashboard plugin may consume trip and um log data from your plugin ?