[C320-list] Data IN ... Data OUT Garmin to AutoHelmST4000Plus

Sun Dec 23 18:36:41 PST 2007

Bill,
Wonder what is up with your setup.  We have a garmin 48 and we are able to follow routs with the raymarine.  Once it passes the mark the autohelm sounds an alarm until you hit track again acknowledging the new course.
Bruce
Somerset 671 SoCal
Sent via BlackBerry by AT&T

-----Original Message-----
From: Bill Culbertson <billculb_a2 at yahoo.com>

Date: Sun, 23 Dec 2007 18:12:13 
To:C320-List <c320-list at catalina320.org>
Subject: Re: [C320-list] Data IN ... Data OUT Garmin to AutoHelmST4000Plus

Sounds like a great trip!  It definitely helps to have the auto-steering for those kinds of distances.

A couple of things that I've noticed with my set up.  One  - you need to be already on course toward the waypoint with low cross-track error when you engage 'track mode'.  Else it will yell and won't engage.  For quite a while I didn't realize why it wouldn't.  Easiest way is to set the goto right before you engage track mode because you'll be at zero XTE at that time.  Two (and this could easily be just my setup), I've never been able to get it to engage track mode IF I've got the Garmin following a route.  Just won't do it.  So I follow the route sort of manually.  I engage the route and see the next waypoint.  Then I disengage the route and set the Garmin to navigate to that particular waypoint.  Engage track mode and I'm on auto.  Have to repeat for the next waypoint.  My typical trips only have maybe one waypoint change per hour so this isn't a major headache and gives me something to do :).  Still, I wish I knew how to resolve that.

 -bill

----- Original Message ----
From: Bruce Stanley <brucestanley36 at gmail.com>
To: C320-List <c320-list at catalina320.org>
Sent: Sunday, December 23, 2007 5:47:35 PM
Subject: Re: [C320-list] Data IN ... Data OUT Garmin to AutoHelmST4000Plus

Bill
thanks.
I'm off to the boat for a go at this ... we are hoping to do a 150nm trip as
of 27thDec!
It would be great to have the GPS steering to wpts at times!

cheers

Bruce Stanley #1084
Sydney Australia

On Dec 24, 2007 9:37 AM, Bill Culbertson <billculb_a2 at yahoo.com> wrote:

> Jeff is correct, Bruce.  What you are calling the 12v Ground is indeed the
> 12v Ground and it is also the data ground. The data signal voltage on the
> brown wire is relative to the Garmin ground wire.  So without that wire
> connected to the -ve end of the NMEA input of the autopilot, the Garmin
> signal voltage connected to the +ve end of the NMEA has no reference point.
>
> What can be confusing about the wiring is that the Garmin both sends data
>  and receives data.  So logically the garmin would have six wires.   data out
> and its gnd, data in and its gnd, 12v and its gnd.  As is customary when
> there is not an electrical reason to keep separate, the Garmin unit uses the
> single gnd wire for all three gnd purposes.
>
> Garmin    data -> -> -> -> data -> (brown)  -> NMEA + in
>                data <- <- <- <- data <- (white)
>                12V
>                GND    -    -    -    -    -    -    -    -    NMEA - in
>
> Remember Jeff's advice to switch the Garmin unit to NMEA mode from Garmin
> mode.  I forget this nearly every time I bring my 176 back onboard from
> having taken it home to transfer track data to my PC. The PC wants Garmin
> mode, the ST4000 wants NMEA mode.  I've taken to leaving it in NMEA mode.
>  It's less disturbing if my PC won't upload track data then when I'm onboard
> and the Garmin won't talk to the ST4000.
>
>  -bill
>
> ----- Original Message ----
> From: Bruce Stanley <brucestanley36 at gmail.com>
> To: C320-List <c320-list at catalina320.org>
> Sent: Sunday, December 23, 2007 4:28:47 PM
> Subject: Re: [C320-list] Data IN ... Data OUT Garmin to AutoHelmST4000Plus
>
> Hi Jeff
> Do I read the 2 lines below:
> ----------------------------------------------------------
> Brown Data OUT wire from Garmin  --->  To Raymarine NMEA +
> *GROUND wire* from Garmin cable    --->  To Raymarine NMEA -.
> ----------------------------------------------------------
> to mean that the *"12v" GROUND wire* from the Garmin ---> to Raymarine
> NMEA???????
>
> Bruce Stanley
> Sydney
> ==================================================
> On Dec 24, 2007 6:54 AM, Jeff Hare <catalina at thehares.com> wrote:
> > Hi Bruce,
> >
> >  I probably should have researched this first, but from memory and what
> > you've provided:
> >
> >  Garmin uses a 4 wire cable.  Power +12, NMEA Data IN,  NMEA Data OUT,
> > GROUND (0v)
> >
> > For this application, I believe you'll be using the GARMIN BROWN (Data
> Out),
> > and the Ground wire.
> > On the Raymarine end, I believe you'll connect:
> >
> > Brown Data OUT wire from Garmin  --->  To Raymarine NMEA +
> > GROUND wire from Garmin cable    --->  To Raymarine NMEA -.
> >
> > This effectively TRANSMITS NMEA Sentences From the Garmin to the ray
> marine
> > NMEA Listening port.
> >
> > Since you don't need your GPS LISTENING to NMEA 1083 sentences from the
> > RayMarine autopilot (other sources), you won't use the White DATA IN
> line.
> >
> > Does this make sense?
> >
> > Also, when you set up your Autopilot, you need to be sure that it's
> > listening to NMEA 1083 as well as setting the Garmin transmitting mode
> to
> > NMEA 1083.
> > Usually the Garmin transmits using "GARMIN" protocol, so if you haven't
> > changed that, you'll need to.
> >
> > I hope I got this right, but no harm will come if polarity is reversed
> here,
> > because they're only signal lines.
> >
> > If you need longer runs, standard network cable CAT-5 used for computer
> > networks is just fine for this.
> >
> > -Jeff
> >
> > PS: I believe that you can drive up to 3 NMEA devices from the NMEA 1083
> > output of your Garmin.
> >
> > -----Original Message-----
> > From: c320-list-bounces at catalina320.org
> > [mailto:c320-list-bounces at catalina320.org] On Behalf Of Bruce Stanley
> > Sent: Sunday, December 23, 2007 3:54 AM
> > To: C320-List
> > Subject: [C320-list] Data IN ... Data OUT Garmin to AutoHelmST4000Plus
> >
> >
> > Data IN and Data OUT
> > Can you clarify?
> >
> > Firstly, I have the GarminGPS48 connected to my ST4000+
> > I have 12v power, but
> > "NO DATA".
> >
> > Garmin say:
> > White=Data IN
> > Brown=Data OUT
> >
> > ST4000Plus say:
> > NMEA +, and
> > NMEA -.
> > ==============================================
> > do I connect Garmin "White" to ST4000Plus "NMEA -"        ?????????????
> > ==============================================
> > HELP, PLEASE
> > Have a great Festive Season, tooooooooooo
> >
> > Bruce Stanley
> > C320 #1084
> > Sydney Australia
> >
> > PS I have looked on Garmin and Raymarine sites...2 glasses of Red Wine
> > Later I gave up!
> >
> >
> >
> >
>
>
>
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