Hi Dave!
The good news is we survived the tsunami and I was able to make the upload
work. But there are many issues that need to be resolved. I'll try and be as detailed as possible.
Waypoint Names
Waypoint names in the
Furuno can be a maximum of 6 characters and can contain uppercase letters and digits. I was only able to successfully upload a
route if all waypoint names were 6 digits. For testing purposes, I named them TST001, TST002... I tried lowercase letters and they did come across, but showed up as special characters rather than lowercase letters.
I know the
Maxsea program could upload waypoint names that were less than 6 characters in length. I changed on of the waypoint names to TST1 with 2 following spaces(OpenCPN let me do this) and tried the upload again and it was successful. In reviewing the NEMA stream, the trailing paces were passed along in both PFEC and GPRTE sentences. Appending trailing spaces to waypoint names that are less that 6 characters would solve this problem.
I also wondered what would happen if a waypoint name contained more than 6 characters. I setup a
route that contained waypoints named TST018 and TST018A. Much to my surprise the upload was successful! But when I went to check the waypoints in the
GPS to see what was uploaded, there was only a waypoint for TST018. This waypoint contained the lat/long from waypoint TST018A. It appears that the
Furuno completely ignored the 7th character and simply overlaid the lat/long with the data from TST018A. I checked the route and it showed TST018 twice. But the upload still worked!!
GPRTE Sentences(Route upload sentences)
There are a number of issues with these sentences.
There is a difference in the way these sentences are being created depending on whether the route has been given a name or if it is an "Unnamed Route". I was not able to successfully upload an unnamed route. It appears that the route number in Segment 4 of the GPRTE sentence is "0" or "1" for unnamed routes and "01" for named routes. My manual, dated June of 1998, indicates that this segment must be a number from 01 to 30 and that 2 digits are required. Since Furuno GPS's clear all existing routes and waypoints in the
GPS when an upload takes place, this could simply be hardcoded to have a value of "01".
When uploading a
named route with more than 6 waypoints, the waypoints are report in groups of 5 in each sentence. If a route has 7 waypoints, the first GPRTE sentence contains the first 5 waypoints and the second sentence contains the remaining 2. When a route contains 6 or less, all the waypoints are sent in a
single GPRTE sentence. This behavior is different when working with an
(Unnamed Route). With an unnamed route the waypoints are grouped 6 per sentence. I don't believe that this should be a problem as my
documentation indicates that 8 waypoints can be reported in each GPRTE sentence and as my testing showed, 6 waypoints can successfully be uploaded in a
single sentence when the route only contains 6 waypoints. I suspect this is a problem with the route number as described above, but I am not certain about this.
Another issue occurs with named routes that contain 11, 16 or 21 waypoints. With a route with 16 waypoints, we would expect that 4 GPRTE sentences would be created. The first 3 would contain 5 waypoints and the 4th would contain the last waypoint. There is a counting error in the program. Segment 1 of the GPRTE sentence represents the number of sentences that will be sent to to complete the entire route. In this example, Segment 4 had the correct value of 4, but only 3 sentences were transmitted. The 4th sentence that contained the final waypoint was not created and so the upload fails in these case. It works fine if there are 12, but not when there is only 1 waypoint to report in the final sentence.
If there are more than 20 waypoints in a route, the program attempts to create 5 sentences to report all waypoints. Since the Furuno limits this to 4 sentences, the update fails for routes with more than 20 waypoints.
Suggestions
Since the Furuno GPS has the little quirk of erasing all waypoint and route data when you perform an upload, it might be a good idea to include a warning box when you first check the box in the Toolbox>connections
screen indicating you want to "uploads in Furuno GP3X". Most Furuno users are aware of this but it may save you from a few nasty emails from the guy who just spent the last 2 weeks manually entering waypoints into his GPS. I also think this option should apply to an individual COM port rather than globally. I'd like to connect a Garmin handheld GPS to another COM port and have the option of uploading a route to either GPS.
Waypoint names are a problem with the Furuno. Padding names shorter than 6 characters would solve that particular problem but still leaves a potentially dangerous situation as I described about with waypoints named TST018 and TST018A. I don't think you would want to limit the waypoint names to just 6 characters in OpenCPN. Many, many years ago I used the program The Cap'n as my
navigation program. Uploads to the Furuno GPS using that program were simply named CAP001, CAP002... I think that would be an acceptable way to name the waypoints in OpenCPN. They may not match the names in OpenCPN, but it is still much better than risking the situation where a duplicate name may cause a waypoint to omitted from an upload.
Since the Furuno allows for up to 30 waypoints in a single route, it would be nice if we can try to put 8 waypoints in each GPRTE sentence. If we use the
current 5 waypoints per sentence we will be limiting a route that can be successfully uploaded to only 20 waypoints. I'm not sure why, but the
Maxsea program limits uploads of routes to 20 waypoints. Perhaps there is a reason I don't know about that requires they be done only 5 per sentence.
I think that's all I have! I'll be more than happy to assist in testing this and any other feature that's within my area of expertise in the future. I was a
software developer for 35 years, so I might be able to be of some help in the future!
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