Connecting Chartplotter to VHF/DSC

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celtictemple

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I recently purchased a Garmin 451 chartplotter as the boat I bought didn't have one. Then I found the old VHF was kaput so I purchased a Midland Neptune VHF/DSC radio. Fine- I got both connected to power but now I realise I need to connect them with each other for the DSC to locate my position. This is a bit of a first time venture for me but I am usually OK working things out. The instruction manuals aren't really that helpful unfortunately, hence my submission to the forum.The Garmin has a bundle of multi coloured wires coming from it to connect to various things including a radio. The radio has what looks like an 8 pin male plug coming from it and also supplied was an 8 pin female plug with a wire ending in a green and yellow wire. Now, I know I am a newby at this, but I do realise the plugs go together to obtain a wire which now comes from the radio and ends with 2 wires , one yellow and the other green. Question-what wires from the charplotter do I connect them to-do I need a special plug or cam I just join them any old way?
 
You'll need to consult both manuals for the wiring schematics, you need to find the wires for NMEA.

VHF NMEA + IN >> GPS NMEA + OUT
VHF NMEA + OUT >> GPS NMEA + IN

Each unit will have NMEA common or -ve. Connect those together too. Any secure and if needs be waterproof connection method is fine.

If you're still unsure, post back with the wiring diagrams or details from both manuals.
 
The midland Neptune doesn't have nmea out, only nmea in. The yellow and green wires are nmea in + and -, and need to be connected to the chartplotter nmea out + and -. I used to have a Neptune but I've never dealt with garmin, so I don't know which wires to use there - as said above, the manual should have a page detailing the wire functions / colours. Also check the midland manual cos I may have got the polarity above wrong!!

Connect garmin nmea out + to Neptune nmea in + and garmin nmea out - to Neptune nmea in -. Easy!

Any type of connector should do...
 
Absolutely spot on, I used crimp connectors and a little bit of insulation tape - I didn't have any heat shrink but will apply that one day.
If you are in any doubt phone Garmin or, who did you nuy the kit from as some suppliers are very helpful. (MES for one)
 
Don't forget to change the data format of the COM 1 port on the Gps451 to "NMEA" mode instead of the default "Garmin"

Connect the Rs232 TX of the Garmin to the Rs232 RX of the VHF and GND to GND. The GPS transmits the nmea position sentances to the VHF.
 
Thanks everyone for replying-very useful info. Although the Garmin gives the colour codes for the NMEA wires, the Midland Neptune doesn't -only the 2 cololured wires. Good idea about contacting supplier-will do. Cheers
 
celtictemple said:
Thanks everyone for replying-very useful info. Although the Garmin gives the colour codes for the NMEA wires, the Midland Neptune doesn't -only the 2 cololured wires. Good idea about contacting supplier-will do. Cheers
Click to expand...

According to the manual you need to connect a GPS adaptor cable to the VHF set. Should have been included with the set and looks to only have two wires. Do you have this cable ? What does it look like and what colour wires ?
 
Just received reply from Engineer at importer of Midland Neptune receivers. He sent pin diagram and said GPS+ data is connected to green wire and GPS- data to yellow wire. The as a parting helpful shot said if that doesn't work, try connecting them the other way round!!!!-glad I asked:confused:
 
celtictemple said:
Just received reply from Engineer at importer of Midland Neptune receivers. He sent pin diagram and said GPS+ data is connected to green wire and GPS- data to yellow wire. The as a parting helpful shot said if that doesn't work, try connecting them the other way round!!!!-glad I asked:confused:
Click to expand...

Lol, very helpful. Just hook them up one way and see if you get the coords on the VHF, if not swap them over. With my setup i get the coords pop up on the VHF set almost instantly. I actually get the coords displayed on the set, but from reading the Midland manual you get an icon, think it said a globe.
 
Request help with DSC hookup, please.

Hello all. I just bought a DSC VHF that I am trying to interface with my chartplotter. I can usually figure out wiring issues but this stuff is just flat out confusing me.

Existing I have:

Raymarine C120 chartplotter display
Raystar GPS 125
Raymarine DSM 300 sounder
Raymarine (can't remember) transducer

My GPS is hooked to the chartplotter display port through a 3 pin Seatalk cable.

I am trying to interface a Uniden UM525 VHF with the above so as to be able to use the DSC features.

I have a vacant NMEA in/out port on the back of the chartplotter. I also have an unused 5 pin cable that goes into it with the following wires and assignments (according to the chartplotter display manual):

brown = NMEA output (-ve) common
yellow = NMEA output (+ve)
green = NMEA input (-ve) common
white = NMEA input (+ve)
black (screen) = not connected

The UM525 has the following wires:

PIN COLOR EXT
1 YELLOW NMEA 0183 IN -
2 ORANGE NMEA 0183 OUT -
3 RED Not Used
4 WHITE NMEA 0183 IN +
5 GREEN NMEA 0183 OUT +
6 BLACK Not Used
7 BLUE External Speaker - /Ground
8 BROWN External Speaker +

So, after all that, my question is how to hook it up. Can I use the vacant NMEA port with the cable on the chartplotter display or do I have to wire it with the GPS and Seatalk cables? Also, can anyone help with the hookup sequence?

Thanks for your time.

Barb
 
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