Garmin GMI10: How do Drift and Anchor Drag alarms work?

vas

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Evening all,

Rather confused after the first few days onboard MiToS, so yet another question.

Got a NMEA2K back bone with a DTS800 thruhull sensor, a GPS antenna, 2 GMI10s and a GPSMAP751. Two more GMI10s (all four courtesy of JFM!) to install on f/b helm next week together with the analogue to NMEA2K engine data device I got to wire and tune.

Problem is that on anchoring for overnighting, I want to setup an anchor drag alarm.
Now, GMI10 after firmware ver 2.90 supports it, mine are on 3.something so they are fine.
One of the GMI10s is on the main cabin close to my ear for obvious reasons.
Thing is I went through all the menus a dozen times and couldn't understand HOW to setup the anchor drag alarm.
I mean from the menu I can setup the alarm as in how many meters off target it starts beeping.
But haven't got a clue on how to set the anchor reference point in the first place!
Hence no matter what distance I set the anchor drag alarm to, it never activates, even when I motor off the place the next morning...

I'd have thought that there should be a way of setting and recording the co-ords of the anchor drop point and use that.
Is it a matter of setting a waypoint or a marker on the GPSMAP751 and then it's somehow magically communicated to the GMIs?
Am I missing something?
I really have no clue.

Needless to say I ended up setting a depth alarm at 2m (was at 2,8-2,9m depth) and that was OK, but I'd rather have the proper anchor drag alarm next w/e as it's unlikely it's going to be as flat as it were last w/e.

cheers

V
 

jfm

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Hmm. I've never set the alarm from the gmi10 or 20 - I always do it from the plotter screen. There, it takes the current gps position is the reference point as soon as you hit "done", so it sounds the alarm if you move outside a circle centred on that point. Obviously you choose the radius of the circle and obviously the circle might not be centred on the anchor, but no matter

But that is via the plotter as I say., not GMI 10/20 The literature for GMI 10 says it will do anchor alarm, and the unit most certainly contains a bleeper, but I don't know how. A quick googled didn't provide the answer for me. I'd contact garmin tech support, otherwise I can email you a garmin contact who will know

In meantime you can load an anchor drag app onto your smartphone
 

vas

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Hmm. I've never set the alarm from the gmi10 or 20 - I always do it from the plotter screen. There, it takes the current gps position is the reference point as soon as you hit "done", so it sounds the alarm if you move outside a circle centred on that point. Obviously you choose the radius of the circle and obviously the circle might not be centred on the anchor, but no matter
yep, I understand that J, only that plotter is on lower helm, I'm a heavy sleeper and worried that I wont hear it. Further, don't see any point keeping a more energy consuming device on if I can get away with a tiny screen ;)

But that is via the plotter as I say., not GMI 10/20 The literature for GMI 10 says it will do anchor alarm, and the unit most certainly contains a bleeper, but I don't know how. A quick googled didn't provide the answer for me. I'd contact garmin tech support, otherwise I can email you a garmin contact who will know
an extensive google didn't help either :D
If you could pass the email of your garmin contact I'd really appreciate it, as it seems that my Sony Xperia Z phone is happy to connect via garmin helm to the 741 plotter, plotter sees it fine, but garmin app on the phone is just stuck for ever on the connecting screen. Daughter managed to foobar wife's ipad and son managed to loose the charger for an older android tablet so I'm stuck with phones that cannot connect, nice!

In meantime you can load an anchor drag app onto your smartphone
yep, done that ;)

cheers

V.
 

jrudge

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I have gmi 10 and did not know this was a feature.

When mine was new I had a buzzer from the helm plotter installed in the master cabin. This need not be a garmin part - the plotter has an alarm output that powers it so pennies from eBay.

I would think this will be a louder solution than a gmi 10 making a chirping noise. Mine wakes me up !
 

vas

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Hi vas,

If no one else provides the solution I'm going to the southampton boat show on Friday so im happy to wander along to garmin and ask on the stand

thanks for the offer J,

Only other thing I found searching the web, is that it needs some antenna or GPS device to be able to set the anchor point so that the alarm actually has a reference point.
How this is done is a mystery. So please if you have 5mins try and ask, shouldn't be something too cryptic...
Ah, and while you're at it, ask why my xperia Z with latest android whatever OS and latest ver of garmin helm WONT go past the first screen "Searching network MiToS_GPS for devices" when the GPSMAP741 does see the device connected!
Will try tonight with wife's Ipad in case I've got something wrongly configured on the garmin.


I have gmi 10 and did not know this was a feature.

When mine was new I had a buzzer from the helm plotter installed in the master cabin. This need not be a garmin part - the plotter has an alarm output that powers it so pennies from eBay.

I would think this will be a louder solution than a gmi 10 making a chirping noise. Mine wakes me up !

true, can do that, but it means I keep the plotter on all night for no apparent reason. Bow cabin is not that big and garmin is at ear level some 1m away, so it will wake me up ;)
Further I think that the GMI also has an alarm output (got to check that so could install a larger beeper if needed.

cheers

V.
 

jfm

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Only other thing I found searching the web, is that it needs some antenna or GPS device to be able to set the anchor point so that the alarm actually has a reference point.
How this is done is a mystery.
It knows its lat/long because it is on same n2k network as the GPS mushroom. Logically it should just remember its GPS position at the moment you first set the alarm, and then bleep if you move outside a 40m (or whatever) circle around that point. That is exactly how the anchor drag alarm on a Garmin MFD works
 

vas

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just to close this thread,

after an exchange of a dozen emails between JFM, Garmin support UK and myself, we realized the obvious:
Set the distance for the dragging on the menu and then simply activate the alarm.
It automatically picks the point at the coords that the GPS mushroom on the NMEA2K network records the moment you hit the YES on the anchor alarm menu...

Tested it yesterday at 2.5m of water, flat as a flat thing and no wind with around 15m chain out (for fun!) and 3m radius :D
Beeped while I was swimming around the boat...

Now, why it didn't work on my first test, I think it had to do with the units and numbers I'd added.

Concluding any GMI10 or GMI20 is capable of anchor drag alarm as long as its on a N2K network with a mushroom and the GMI10 has a firmware > than 2.9 (current version 3.7)

hope it helps someone ;)

cheers

V.
 

jrudge

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I have never seen that on my menu. I will look next time. I have a number of them and then are all circa a year old so I would assume that they are > V2.9,

The GMI tends to would on views, so do I set up an anchor alarm view?
 
D

Deleted User YDKXO

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Now, why it didn't work on my first test, I think it had to do with the units and numbers I'd added.
It is surprising how little a boat actually moves even in quite strong winds although it may appear that it is swinging around a lot. I have a phone app that I set to a radius of 50m for overnight anchoring and my boat usually never comes close to swinging out of that radius

Apropos nothing at all, I always switch on the Track mode on my plotter when anchoring and after a night at anchor it is interesting to see in the morning the arcs through which the boat has been swinging and how changes in wind direction and strength changed those arcs
 

vas

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I have never seen that on my menu. I will look next time. I have a number of them and then are all circa a year old so I would assume that they are > V2.9,

The GMI tends to would on views, so do I set up an anchor alarm view?

easy to check the firmware, and imho worth downloading and updating everything on your N2K network. Be warned it's not a quick process! Probably took a good 10mins for each GMI10

Yes, GMIs tend to focus on views, but NO you don't setup a view, there's an alarm page from the menu, go through that and you'll find it in no time

BTW, the GMI10 manual doesn't mention anything about the anchor drag feature as it wasn't available when the model was introduced and the manual done. Please download GMI20 manual and have a read ;)

cheers

V.
 
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BruceK

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I have the phone app. I cant hear the plotters at the helm when asleep. I set the anchor position at the point I drop anchor, before backing up and laying out chain. With up to 30 foot tides and a reasonable dropoff gradient it doesn't give much scope for error, and I have to minimize radius as much as possible because with just a 100 foot of chain at LW I'm at six foot depth and close to shore/rocks and at high water stretching it a bit thin with a tad over 3:1 scope. I set my radius to a max 30m. If it beeps I know I'm in trouble. If I didn't set the anchor point precisely the radius would have to be bigger and I could be in trouble before being warned.
 

vas

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Bruce, makes sense for you, down here with probably a foot tide it makes much less of an impact.
I agree finetuning the radius is a must, especially during peak season with lots of craft around.
Phone app I used a couple of weeks ago showed indeed some interesting patterns all within the 20m radius I'd set.

cheers

V.
 
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