confusing nmea wirring

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Jan 14, 2011
243
tanzer tanzer 28 bathurst nb
ok i am a dinosaure with computer and i am scared of burning or frying anything here, i decided to refresh the electronics on my boat so i got a new autopilot, it is a simrad tp22, and a new vhf, wich is a standard horizon eclipse dsc gx1000s, and a new depth-knot meter from raymarine(bidata st 40), i already had a garmin gpsmap 60 cx, so i bougth the cable to have it comunicate with the other instrument....

so far i get that the autopilot can only have one thing talking to it so i dont really need to hook up nmea conection to the depth and knot meter, since i want the autopilot and the gps to communicate and the gps and the vhf to comunicate in case of emergency,is the vhf going to talk with the autopilot,i sure hope not but who know...

now i have to play with as wires...

VHF purple-nmea out(pos), green-nmea out(neg), blue-nmea in(pos)

GPS brown-serial data out, white serial data in, black ground, red power 10-32VDC

PILOT one sim net plug, red 12VDC POS, black 0V, red nmea data out pos, blue nmea out common

so now here i sit with a bunch of wire and no idea wich one goes with wich! they are all tiny and they all scare the crap out of me that i migth burn one of them new toy, i know they are all the same nmea 0183 from wath i can see , but iis there some guru out there who could put a diagram on how to plug them, or offer a good explanation of how to plug them!

thank in advance for any advice!
 
Oct 2, 2006
1,517
Jboat J24 commack
Well

The GPS should have two NMEA channels and you can use one for the autopilot and one for the radio

If the GPS was NMEA 2000 you could do a network of more stuff If the stuff was NMEA 2000 :)

For what ever reason the color codes on the com wires are not standard BUT output goes to input and you just need to take a pen and paper and the manuals and ID the colors from each unit

And for added fun there are a few flavors of 0183 that do not play well toghter
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
good news and wires

NMEA is a 5 volt ground referenced system. Not much chance of burning out circuits here if you connect them wrong.
NMEA uses 4 lines (3 sometimes if they have a common ground.) The talker line (out), the listener line (in) and the grounds. The grounds are very important as they provide a reference that helps eliminate the noise in the data lines (in and out).
So connect the talker (out) to the listener (in) for the arrangement you have. Note that NMEA is a single talker many listener type circuit so you might have two listeners on a circuit.
The grounds are a little more complicated as some have "common" and others have dedicated. If you tie two dedicated grounds together they become a common ground. It is OK but not desirable to do that. Sometimes you have no choice though.
For you setup you have
GPS: (brown) talker, (white) listener, and black common (talker and listener) ground
VHF: (purple) talker, (blue) listener, and (green) talker ground. Should have a listener ground also, where is that???
Auto: (red) talker, and (blue) talker ground. No listener???? Does your auto set up your courses??? Perhaps the sim plug is the listener circuit.

So your GPS can talk and listen, the VHF can talk and if you find the listener ground can listen also but your auto pilot can only talk. You typically want to receive data for the auto pilot to be completely integrated. The data exchanges are typical below and do not represent the total set of date exchanges. Your mileage may vary;
From GPS position info to VHF so it can do its emergency channel 70 reporting of your position [gps brown to vhf blue, gps black to the wire on the vhf that you have not found ;-( ]
From GPS to auto (can’t do that given the wires you have) to pass waypoint speed, course, and location so you can do some VMG, course verses heading, turn to head to next waypoint and time to go stuff.
From VHF to GPS no data exchange required
From auto pilot to GPS to confirm waypoint turn, heading (not course, auto does not do course without GPS) [ap red to gps white, ap blue to gps black]
So you have some wires to find (which is probably why it is confusing) as you don’t have any circuits that can be connected together and give you anything useful. Sorry not the answer I wanted to give but a spade is a spade. If you have the manuals you can probably figure out what is going on. You auto pilot may not be GPS capable and only reports out what it is doing but cannot take commands from the gps in course control mode. The manual should tell you that also.
 
Sep 29, 2008
1,944
Catalina 310 #185 Quantico
This should be simple

Mesange, Don't get too worried about the wiring. I have not used a Simrad AP, but it should not be too different. You have done the hard part by connecting all of the wires. Here is a wiring diagram I did when wiring my electronics together that should clarify a lot (Note I only have my Garmin or my Humminbird in at any one time as you can only have 1 master GPS, e.g. outputting NMEA sentences). I do have a Standard Horizon VHF and that is also pretty straight forward.

First thing is to hook all the power up to these devices so they turn on, and that also helps you eliminate 1/2 of your wires.

1. All of your grounds should connect together (GPS - black ground, AP - black 0V, VHF black ground).
2. All of your power should connect together

For the rest of it you are only dealing with low power data signals (note my comment about connecting all of your grounds together; if they are not you may get a little float or difference in ground and the NMEA signal can be obscured; yes the voltage is that low). Hook the data wires up one at a time and if it is not working, flip the wires. There are typically only two wires NMEA-In and NMEA-Out. I had everything hooked up and could see the NMEA sentences with a meter on the wire (you will see a slight pulse with the voltmeter at a low range). My SH VHF was the big bugaboo and it all just magically worked when I hooked the 2nd ground in my drawing at the power panel where the VHF main unit was.
 

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Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
so what does it do after connecting???

hey rpwilla
so what does your auto pilot do now that it did not do before connecting it to the GPS?
I'm kinda interested as the way I read mesange's wires he can't have the ap taking commands from the GPS.
 
Sep 29, 2008
1,944
Catalina 310 #185 Quantico
BTW, Here is how you know the VHF sees NMEA

It is pretty clear. You don't have it and then you do. Note that on Raymarine AP's they have two connectors on the back so in my previous drawing I did not specify wire color as it will be what I had on hand; with yours it is red nmea data out pos, blue nmea out common.
 

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Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
power grounds and signal grounds

for the record, a power ground and a signals ground are NOT the same thing. If you connect them together you tend to get noise in the signal circuit. Noise is not a good thing in signals circuits.
Course it appears that SH does just that (and them being a radio manufacturer should know better)
 
Sep 15, 2009
6,243
S2 9.2a Fairhope Al
for the record, a power ground and a signals ground are NOT the same thing. If you connect them together you tend to get noise in the signal circuit. Noise is not a good thing in signals circuits.
Course it appears that SH does just that (and them being a radio manufacturer should know better)

am i to assume that the power ground is the neg side of 12 vdc and the signal ground is likened to the earth ground plate on the hull.....

regards

woody
 
Jan 14, 2011
243
tanzer tanzer 28 bathurst nb
so on my auto pilot i will have to cut the sim net plug and find out wich wire do what , there is probably about 8 more wire in there, so if i understand corectly i plug the out of the gps to the in of the accesorie i want to get the signal to, and the ground to the boat ground or battery negative?

anyone know wich wire are wich in the sim net plug, this is a brand new simrad tp22
 
Jan 22, 2008
880
Fed up w/ personal attacks I'm done with SBO
Mesange,

I'd suggest making one connection at a time and then testing operation. Bring these components together incrementally.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
SIM plug

The sim plug is most assuridly not nmea format!! It is probably TCP/IP but could also be Simrad formated (propriatary!!!:cussing:)

I went and got the manual for simrad tp22 and if you read the section on nmea setup you will see that the red and blue wires are actually listening lines not talking lines so you sould be good to go after making that mental jump. the little box has "NMEA talker unit" (aka GPS) and "Tiller pilot NMEA A" headings. Typical confusing documentation.

So red is listening data and blue is listening ground.
 

kenn

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Apr 18, 2009
1,271
CL Sandpiper 565 Toronto
No thanks to the manufacturers, NMEA 0183 in practice is a jungle. Besides not standardizing on connectors and colours, some manufacturers also cooked up some 0183'ish proprietary dialects and non-standard connectors and colours, and defaulted their equipment to their own dialect, with the choice of genuine compliant NMEA 0183 buried somewhere in the menu.

With research and some reflection, you will be able to diagram what instrument talks to which, and then burrow into each unit's wiring and configuration. Assuming you bought the new gear from a local store, it would be well worth buying the salesman a beer and going over your desired setup and how he recommends hooking up. Especially if there's still a warranty in force ;)
 
Jan 14, 2011
243
tanzer tanzer 28 bathurst nb
thanks everyone this makes it a lot eisyer to understand , it is just a matter of indetifing the wires! it is starting to make sense the more i read everyone answers! a big thanks to every one, this is a great forum with great member's! will deffinately go one at a time
 
Sep 29, 2008
1,944
Catalina 310 #185 Quantico
GPS will drive the AP

hey rpwilla
so what does your auto pilot do now that it did not do before connecting it to the GPS? I'm kinda interested as the way I read mesange's wires he can't have the ap taking commands from the GPS.
With my Raymarine AP, if I have a route set into the GPS, it will send the command to the AP to turn at the waypoints and such. I don't use it that much as most of the time, I simply set a course so my hands are free, bit it is cool.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
cool interconnect stuff

hey rpwillia
I have the raymarine system also. i love the tack angle feature. Tells you what your new tack bearing will be if you tack and keep everything else the same. Then just wait till the course yor want lines up with the new tack course and bang, one tack to destination.
Also like the sail to wind angle feature. the normal auto pilot just does not cut it when trying to sail a course and the winds change over time.
 
Sep 29, 2008
1,944
Catalina 310 #185 Quantico
I also like the sail to wind feature

Also like the sail to wind angle feature. the normal auto pilot just does not cut it when trying to sail a course and the winds change over time.
That is pretty useful with steady wind. On light wind days that can drive you nuts though and on the Potomac some days steady wind is a scarce commodity.
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
light wind days and auto pilots

I know what you mean rpwillia
I have found that when the wind speed is below the hull speed of the boat the apparent wind just shifts all over the place. One technique that I've used is to start on a beat that has the wind coming from athwartships and once up to speed, start cranking in the wind angle till you are beating at speed toward your destination. Sometimes I have to start by going in the wrong direction to get the boat speed up but the final making your own wind solution is pretty stable.
Course one good powerboat wake can ruin it by killing your boat speed!:doh:
 
Sep 29, 2008
1,944
Catalina 310 #185 Quantico
I understand that one

Course one good powerboat wake can ruin it by killing your boat speed!:doh:
We have those in spades on the river. Makes it fun when you are on a mooring working below upside down in a locker and the boat keeps bouncing up and down.
 
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