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[svadagio]

First or main puck Garmin 18X
Back up puck BU-353
Bob

[shorebird]

Sorry to jump into this thread, I have not read the whole thing, so if this is mentioned by anyone, apologies. When I first got my handheld GPS it persistantly put my location about 20 miles away, and it took a long time to figure out why. The problem was the unit was set to read in degrees, minutes and seconds, while I was plotting in degrees and decimalized minutes, not seconds. 20' 30" is 20 minutes and 30 seconds, but would appear as 20.50 minutes as a decimal figure. I simply reset the GPS to read the same way, and my position was spot on.

[nohal]

Bob...
Open the NMEA Debug window and look for the $PGRMM sentence - tell us what you see.

Pavel

[svadagio]

First I checked the format and it is all Dec Deg.xx

Second Opened the gpsdebug window and it had three options
Mesg in
Mesg filtered and dropped
Mesg out
Clicking on them did nothing.

Third I used Oziexplorer to look for the nema sentence and none had what you asked for. All started with $PGxxx.

Bob

[svadagio]

Meant to say none had RMM at the end.
Bob

[cagney]

Originally Posted by svadagio

First I checked the format and it is all Dec Deg.xx

Second Opened the gpsdebug window and it had three options
Mesg in
Mesg filtered and dropped
Mesg out
Clicking on them did nothing.

.......
......

Bob

Those are not options. They are there to explain what the different colored text means. You should look for the message that "nohal" mentioned in the green text that scrolls past.
If you don't see anything, then your GPS isn't working for some reason.

Ozi and OpenCPN will not work at the same time! It's one or the other.

Thomas

[svadagio]

Ok I expanded the window and found the info. I also went back to the Garmin puck as that is the one with the problem. I did not see any sentences ending with RMM. There was two that just keep repeating. $gmrmc and $gmgsv. All were black.
Bob

[nohal]

Bob...
According to the manual for 18X, the RMM sentence contains the information about the geographic datum it is using. It will sure not be transmitted very often, but I suppose the Garmin guys were not that drunk while writing the manual to include something that does not exist...

PAvel

[bcn]

So the BU-353 gives correct results?

Implies that the settings of OpenCPN and chart settings are ok.
So what about the Garmin, and here the Chart Datum?

From the manual
http://static.garmincdn.com/pumac/GP...Tech_Specs.pdf

Following p.13 in the $PGRMC message all the relevant parameters should appear.
Just try to post a screenshot of the Debug window.

Hubert

Ps. Pavel has been a bit faster

[svadagio]

OK Cut and paste is not allowed so here it is hard way

$GMRMC,,A,1821.553,N,06434.969,W,0.075,338.273,,0. 000,*3A

Looking at the spec and this sentence it appears the datum is missing.
Do you agree?
Bob

[nohal]

Bob...
Yep, agreed (Chapter 4.2.7 of the 18X manual). That's why we are hunting for RMM, where Garmin docs say the datum is announced.

Pavel

[svadagio]

Ok 4.2.1 seems to indicate RMM is not normally transmitted. You must need something to ask for it. Any ideas? It said it is used by Garmin software.
Bob

[bcn]

And if you send $PGRMCE to the sensor it will reply with the settings.
(some Terminal program)

The $GPRMM is not ON by default (as you found out as well).
No service program for the settings? --> p. 32 of the manual

[nohal]

Probably SNSRXCFG - Garmin: SNSRXCFG Updates & Downloads could be of some help.

Pavel

[svadagio]

Thanks for the help guys but at this point I see if I had put this many hours in a minimum wage job I could buy several BU-353 and be done with it. I think that is what I will do.
Thanks again
Bob