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GT31 data recorder

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Created by choco > 9 months ago, 5 Mar 2009
choco
SA, 4175 posts
5 Mar 2009 8:56AM
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My Gt31 froze late in the day yesterday it was displaying my times on speed genie but recorded nothing to the card.I downloaded the data from the logger but it's in a different format and my software cannot read it.
How do you go about retrieving data from the logger?

westozwind
WA, 1415 posts
5 Mar 2009 11:16AM
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The data logger file should be XXXX..._DLG.SBP
This file should be easily opened in Real Speed.
You may have to delete trackpoints that are not related to your session as the data logger logs all the time, once the memory fills, it just starts from the beginning again.
Just check the date filed in the bottom right RealSpeed window to ensure you get all the trackpoints related to the session.
Hope this helps

decrepit
WA, 12767 posts
5 Mar 2009 7:12PM
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Yes realspeed will read .sbp files, as will GPSarPro, but if you'r software doesn't read .SBP files. I think "gpsbabel" a free program, should be able to convert it for you.

Dylan72
QLD, 660 posts
5 Mar 2009 9:03PM
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www.ka72.com/ also reads .sbp files.

These files may (usually, really) have several sessions in them. Most software, including Realspeed, will split the file into separate sessions.

You can use GPSBabel (but only really recent versions of it) to convert .SBP files into another format, but you really shouldn't. .SBP files have lots of good information in them, including SDOP data, which give them greater precision than most of the formats that GPSBabel will convert them to.

Cheers,

Dylan.

Bilabog
NSW, 211 posts
5 Mar 2009 11:06PM
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Hi Dylan,
When you set the Navi GT31 to record SBN files Binary logging. in the Memory Card menu ( NMEA ITEMS ) do you also have to change the Interface setting from NMEA to BINARY in the SETTINGS MENU ?or leave the interface NMEA?
It doesn't mention this in the MT-BEST Australia web page on how to set up the Navi GT31 for speed sailing.

Thanks Dylan

Dylan72 said...

www.ka72.com/ also reads .sbp files.

These files may (usually, really) have several sessions in them. Most software, including Realspeed, will split the file into separate sessions.

You can use GPSBabel (but only really recent versions of it) to convert .SBP files into another format, but you really shouldn't. .SBP files have lots of good information in them, including SDOP data, which give them greater precision than most of the formats that GPSBabel will convert them to.

Cheers,

Dylan.


choco
SA, 4175 posts
5 Mar 2009 10:45PM
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Thanks for the info i have managed to recover some of the tracks but the unit must have stopped recording which is strange because speed genie was still displaying my times up until the gt31 froze.
Found the solution though just purchased a second unit......what are the chances of both freezing up

nebbian
WA, 6277 posts
5 Mar 2009 11:00PM
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I'm pretty sure that the "Interface" item refers to the data that is spat out the "serial" port of the GT-11/31. This is used for connecting the Navi to a laptop and showing a moving map of where you are.

By "serial" I mean the serial->USB interface, or serial->bluetooth interface if you have a NAVI with the bluetooth module.


For most speed sailors this option makes no difference.

Bilabog
NSW, 211 posts
6 Mar 2009 5:53PM
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Thanks for the Info Nebbian!

nebbian said...

I'm pretty sure that the "Interface" item refers to the data that is spat out the "serial" port of the GT-11/31. This is used for connecting the Navi to a laptop and showing a moving map of where you are.

By "serial" I mean the serial->USB interface, or serial->bluetooth interface if you have a NAVI with the bluetooth module.


For most speed sailors this option makes no difference.


lao shi
WA, 1338 posts
8 Mar 2009 8:41PM
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I have a weird result from my walpole session where the last hour has a speed of minus 23.1 a distance of minus 59 K in 4985 seconds! What the! Can't seem to find obvious spikes and have deleted invalids. Using Dylans KA72 reader it ignores it.
Any suggestions? This is using GT31 doppler. Not had any errors with it before.

decrepit
WA, 12767 posts
8 Mar 2009 9:25PM
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Lao, I had negative speeds as well on a file, turned out something happened to the time intervals.
In realspeed, check the date/time column for duplicate times. I think if you click the top of the column that should sort that column in time sequence, it's normally sorted by recording sequence.

I think you can only have negative speeds if you go back in time, not sure how the gps does this, but I'd bet it's something to do with satellite reception.
Fortunately with mine, it was at a time I was out of the water, I'd left the gps in my helmet strapped to the rig, when I got back it had an extra 40nm on it. So I could just delete the strange data.



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