Notices

Garmin GPSmap 740

Old 11-28-2017, 08:18 AM
  #1  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default Garmin GPSmap 740

Hello;
I purchased a boat this year with a Garmin 740, connected to a Garmin radar.
Seems to work well, I added a SD map for my area.
The chart plotter was used as a stand alone unit, no transducer connected,
no depth displayed.

The boat also has a Lowrance Elite7x HDI could they share a transducer if it they were both connected to a NMEA 2000 network?

(both devices are NMEA capable)

Thanks.
Brownie289 is offline  
Old 11-28-2017, 08:21 AM
  #2  
Senior MemberCaptains Club Member
 
Join Date: Aug 2005
Location: Cape Cod/Marathon
Posts: 1,311
Default

No, that's a network function. Not NMEA .
caper is offline  
Old 11-28-2017, 08:41 AM
  #3  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default

Originally Posted by caper View Post
No, that's a network function. Not NMEA .
Thank you, so to connect a transducer to the Garmin it must be a NMEA transducer correct?
Brownie289 is offline  
Old 11-28-2017, 08:44 AM
  #4  
Senior Member
 
Join Date: Jul 2011
Posts: 5,458
Default

the "depth finding" - sonar - transducer connects directly to the MFD - not via NMEA 2000.

There were two GPSMAP 740 models, the 740s had sonar capability, the other not.
Fwpratt is offline  
Old 11-28-2017, 08:54 AM
  #5  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default

Originally Posted by Fwpratt View Post
the "depth finding" - sonar - transducer connects directly to the MFD - not via NMEA 2000.

There were two GPSMAP 740 models, the 740s had sonar capability, the other not.
A-Ha!

You solved the mystery for me, it was a used boat and this is what it came with...
Brownie289 is offline  
Old 11-28-2017, 09:12 AM
  #6  
Senior Member
 
Join Date: Jul 2011
Posts: 5,458
Default

Now, you won't "see fish" - or any sonar picture with it,

but there are several ways to get a numerical value for depth, and even temperature or speed from a transducer via NMEA 2000.

There are available "smart transducers" which output those values directly via N2K

and Garmin offers a "transducer adapter" which converts the signal from a compatible conventional transducer onto N2K
Fwpratt is offline  
Old 11-28-2017, 09:40 AM
  #7  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default

Originally Posted by Fwpratt View Post
Now, you won't "see fish" - or any sonar picture with it,

but there are several ways to get a numerical value for depth, and even temperature or speed from a transducer via NMEA 2000.

There are available "smart transducers" which output those values directly via N2K

and Garmin offers a "transducer adapter" which converts the signal from a compatible conventional transducer onto N2K

Ok thank you that's exactly what I wanted to do, I hate having a blank depth display...

So a smart transducer and a transducer adapter. I saw that adapter on the Garmin site but didn't understand if that would work for me.

Let me understand one more thing then...so the transducer would then be part of the N2K network? anything else on the network should be able to access that info?
Brownie289 is offline  
Old 11-28-2017, 10:43 AM
  #8  
Senior Member
 
Join Date: Jul 2011
Posts: 5,458
Default

Originally Posted by Brownie289 View Post
So a smart transducer and a transducer adapter.
Either / or.
The Garmin adapter works with "compatible" ordinary transducers - I haven't studied which are.
There are several "smart" N2K, this is a transom mount:

https://www.starmarinedepot.com/airm...SABEgK-qPD_BwE

The beauty of NMEA 2000, once a device broadcasts data onto the network, it is available to everything else on the network.
Fwpratt is offline  
Old 11-28-2017, 11:55 AM
  #9  
Senior Member
 
Join Date: Jan 2012
Posts: 1,741
Default

I remember asking Garmin about this years ago and I was told that a 740 will accept depth from a NMEA source but a 740s will not. It seemed a bit strange to me at the time but they said their was no way to override the internal sounder as depth source. I never actually tried it.
Amity83 is offline  
Old 11-28-2017, 12:07 PM
  #10  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default

I had an old unused speed wheel through hull transducer.
I removed it and put the blank in the hole.
Maybe I should put a depth, temp transducer.
Brownie289 is offline  
Old 11-28-2017, 05:06 PM
  #11  
Senior MemberCaptains Club Member
 
Join Date: Feb 2005
Location: Falmouth, MA
Posts: 5,479
Default

Whoa. Back up. If the Lowrance is functioning as your sounder you can connect it to the garmin via nmea and the depth will display on the garmin.

The confusion just comes from your terminology of asking if they can share a transducer which is different than communicating the depth over the nmea network.
chainsaw42 is offline  
Old 11-29-2017, 03:16 AM
  #12  
Senior Member
Thread Starter
 
Join Date: Sep 2016
Location: Mystic CT
Posts: 325
Default

Originally Posted by chainsaw42 View Post
Whoa. Back up. If the Lowrance is functioning as your sounder you can connect it to the garmin via nmea and the depth will display on the garmin.

The confusion just comes from your terminology of asking if they can share a transducer which is different than communicating the depth over the nmea network.
Thank you;

So if the Lowrance and Garmin are connected together via network they can share each others Data?

The Lowrance has a skimmer transducer that is glued to the inside of the hull.

I may install a Garmin temp/depth through hull transducer as there is a hole there with a plug in it anyway.
Brownie289 is offline  
Old 11-29-2017, 04:32 AM
  #13  
Senior Member
 
Join Date: Jul 2011
Posts: 5,458
Default

Originally Posted by Brownie289 View Post
So if the Lowrance and Garmin are connected together via network they can share each others Data?
Yes, although not much data.
Sorry - I got to thinking about the Garmin and overlooked the other;

seems you have a depth value on the Elite 7 - that can be shared with the 740 -
via NMEA 2000 or even 0183 (which costs nothing but connecting wires you already have)

You should be able to transfer waypoints created on one unit with the other via N2K
(likely require a sequence of menu selections each time)
Fwpratt is offline  
Old 11-29-2017, 04:36 AM
  #14  
Senior MemberCaptains Club Member
 
Join Date: Feb 2005
Location: Falmouth, MA
Posts: 5,479
Default

Originally Posted by Brownie289 View Post
Thank you;

So if the Lowrance and Garmin are connected together via network they can share each others Data?
yes and no. it does get confusing. lowrance & garmin can communicate via nmea (either nmea 0183 or nmea 2000, depending on model). the information they can share this way is limited though...limited to things such as depth, water temp, heading, position, etc. Things such as sounder returns ('fish finder picture'), radar, chart info, etc do not share between manufacturers over nmea.

Originally Posted by Brownie289 View Post
The Lowrance has a skimmer transducer that is glued to the inside of the hull.

I may install a Garmin temp/depth through hull transducer as there is a hole there with a plug in it anyway.
what are you trying to accomplish with this new transducer? if it is just adding water temp info then I think you're much better off buying a new transducer for the lowrance and sharing the info via nmea to the garmin.
chainsaw42 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread