GPS output Garmin 8612 for active fins

[magna 6882]

I am installing keypower active fins and the control box would like a gps signal from the nave unit. I do not understand nmea 0183 ,rs232,rs485 ect. It is my undertanding rs485 is nmea 0183 but i just dont get it.
I have two 8612 garmin units that have open ports on the back and i know its been done with the same equipment. Can one of you smart guys give me a hand with this problem.
Thanks
Rob

 

[Iggy]

I am surprised that your Nav unit is not NMEA2k. That would make it very simple hook up. I have not used RS-232 in 30 years. I do mean use it but I THINK its at lest 40 years old.

I did fine this adapter. https://www.milltechmarine.com/Actisense-Opto-isolated-NMEA-to-RS232-Adapter_p_493.html

What is very important is speed of that data or bit rate. They must match.

 

[hmason]

I have 3 Garmin 8616’s and they all output NMEA 2K.

 

[twistedtree]

First question is whether your Garmin has an 0183 output, or an RS-232 output. I have zero first hand experience with Garmin, but gather some of the older units us RS-232.


Assuming NMEA 0183, wire according to sheet 5 of the diagrams.


Garmin Tx+ (or TxA) goes to the white wire
Garmin Tx- (or TxB) goes to the green wire.


Garmin Rx+ and - can be left disconnected.


You will need to configure the Garmin to use that port, set the baud rate, and to send GPS sentences, but we also need to know which sentences.


Missing info:


1) You need to know which sentences the Stabilizer needs from the GPS. Those would be the sentences that you enable in the Garmin. This should be in the stabilizer documentation somewhere.



2) You need to know what baud rate the stabilizer is expecting, and you need to set the Garmin to that same speed. The standard with NMEA 0183 is 4800 baud. But AIS requires 38kb, and that same higher speed can optionally be used for other data. But most likely in this case it will be 4800.

 

[twistedtree]

I have 3 Garmin 8616’s and they all output NMEA 2K.

Only N2K? No 0183 outputs available? If that's the case then a converter will be required. Unless GPS info can be pulled from somewhere else.


The stabilizer doesn't have an N2K interface, only RS-422 which is NMEA 0183, RS-485 which is not used at all in marine electronics that I've seen, and RS-232 which hasn't been used by marine equipment since NMEA 0180 and 0182. That said, some stragglers have kept using it as make-believe NMEA 0183.

 

[Cigatoo]

This link will give you your wire coding for Garmin. I am not familiar with your particular model but all of the Garmin products I have ever touched have 0183 capabilities.

https://www8.garmin.com/manuals/web...UID-461DE129-671F-49B9-971C-1D9FBB2D652F.html

 

[magna 6882]

It looks like a cable i may need. There are a couple of ports unused on the back of the garmin units. Right now everything is nmea2000.

 

[pjtemplin]

Yes, I believe it's an "audio and NMEA 0183" cable. Odd that they combine these two, but they come up with plenty of zany things so this one is no surprise.

 

[magna 6882]

I have the cable ordered . There seem to be some settings in the garmin i will need to look at. One thing i am not sure about is how the butt connection work with data lines. I have always treated data lines with punch down boards and connections.

 

[AnsleyS]

Magna,


I have also done connections with the Garmin audio cable. You should have ordered the NMEA® 0183 with audio cable (010-12852-00).


This will go into the green port on the back of your 8612.



The optional NMEA® 0183 with audio cable (010-12852-00) includes bare wires and an RCA connector for an audio out connection to a stereo.

The NMEA 0183 with audio cable provides one differential NMEA 0183 input and output port. You will not need the input port and out of all these wires you will only use the gray, the pink and the brown. The gray is the NMEA + , pink is NMEA - , and the brown is a ground.


Wire the gray to the GPS RS485 J10 pin number 1 of your StableMotion Control Roll Controller and wire the pink to the number 2 pin next to it. The brown goes on the 3 pin . These are way off to the right on the pin board on the controller main board. Check to see that the jumper in JP5 is in the pin 2 and 3 position.



When you are ready go into your GPSMAP 8612 and set the NMEA0183 output settings. SelectSettings>Communications>NMEA 0183 Setup>Port Types . Select the input port and set it to NMEA Std. and then do the same for the output port. (These both may have defaulted to NMEA Standard)


Then go to Settings>Communications>NMEA 0183 Setup>Output Sentences. and turn off all sentences except the ones that are required for you roll controller. The manual should tell you which it wants.


The pin set up and the color coding for the Garmin audio cable look like this.

Pin
Wire Function
Wire Color
1
NMEA 0183 Rx/A (In +)
White/orange
2
NMEA 0183 Rx/B (In -)
White
3
NMEA 0183 Tx/B (Out -)
Pink
4
NMEA 0183 Tx/A (Out +)
Gray
5
Ground
Black
6
Alarm
Yellow
7
Accessory on
Orange
8
Ground (shield)
Brown
9
Audio Left Channel
White
10
Audio Common

Blue/red
11
Audio Right Channel
Red

 

[Cigatoo]

Magna,


I have also done connections with the Garmin audio cable. You should have ordered the NMEA® 0183 with audio cable (010-12852-00).


This will go into the green port on the back of your 8612.



The optional NMEA® 0183 with audio cable (010-12852-00) includes bare wires and an RCA connector for an audio out connection to a stereo.

The NMEA 0183 with audio cable provides one differential NMEA 0183 input and output port. You will not need the input port and out of all these wires you will only use the gray, the pink and the brown. The gray is the NMEA + , pink is NMEA - , and the brown is a ground.


Wire the gray to the GPS RS485 J10 pin number 1 of your StableMotion Control Roll Controller and wire the pink to the number 2 pin next to it. The brown goes on the 3 pin . These are way off to the right on the pin board on the controller main board. Check to see that the jumper in JP5 is in the pin 2 and 3 position.



When you are ready go into your GPSMAP 8612 and set the NMEA0183 output settings. SelectSettings>Communications>NMEA 0183 Setup>Port Types . Select the input port and set it to NMEA Std. and then do the same for the output port. (These both may have defaulted to NMEA Standard)


Then go to Settings>Communications>NMEA 0183 Setup>Output Sentences. and turn off all sentences except the ones that are required for you roll controller. The manual should tell you which it wants.


The pin set up and the color coding for the Garmin audio cable look like this.

Pin
Wire Function
Wire Color
1
NMEA 0183 Rx/A (In +)
White/orange
2
NMEA 0183 Rx/B (In -)
White
3
NMEA 0183 Tx/B (Out -)
Pink
4
NMEA 0183 Tx/A (Out +)
Gray
5
Ground
Black
6
Alarm
Yellow
7
Accessory on
Orange
8
Ground (shield)
Brown
9
Audio Left Channel
White
10
Audio Common

Blue/red
11
Audio Right Channel
Red

Nice!

 

[magna 6882]

Thanks so much for the detail. Your instructions are in line with what i was thinking but i was just punting. Its so nice to get this much detail. Keypower said i only need two sentences . Speed and Heading. I have never looked that deep into the garmin so am unsure what the sentences look like.

 

[AnsleyS]

Magna,


I would start with turning all sentences off and then turning on this one:


GPVTG VTG: Course over ground and ground speed



The sentences listed on the Garmin MFD may have the sender ID which is the first two letters (GP) which means global positioning system (GPS) or it could just have the sentence title (VTG).


If this does not work then you may look down the list and find other sentences for speed and course.


Leave sentences that you don't need off as the transmission speed of NMEA 0183 is 4800 baud which is pretty slow nowadays.

 

[wkearney99]

What data do the stabilizers need? Because there's more than just GPS position data that seems like it'd be useful to stabilizers. Really accurate pitch/roll certainly seems like it'd be useful. I couldn't find anything on their website about what their system can/will use.

There are much better GPS units these days, like Furuno's SCX-20 satellite compass. It'll provide 3-Axis Speed, Pitch, Roll, Heave, Rate of Turn and Heading, at sample rates much faster than older gear.

One nice part is as a combination it can replace separate GPS, fluxgate compass and heading sensors. You can, of course, still have those other units on the network, if you're concerned about redundancy. Just as long as you take steps to make sure your devices are configured to avoid ID# conflicts.

 

[magna 6882]

Today i hooked everything up but in looking at the gps setup on the stabilmotion control panel it says no gps connected.I need to double check my wiring since it was at the end of the day. I did look at the settings and played with them a little but am not sure if its a settings thing or wiring.Is there a voltage test that can be performed or perhaps an ohms test to confirm wiring?
This data stuff is really outside my wheelhouse. I just don't know anything about it. everything on the boat is nmea2000.
Keypower says they only need speed. This is used to deactivate the fins when stopped and set trim at different speeds.

 

[wkearney99]

Are the control panel manual or installation docs online anywhere? It shouldn't be too hard to figure out but will depend on how the Keypower unit expects to be connected. N2K is pretty straightforward, in that if you've got a stable, working network it shouldn't be a problem to add in a tee connection for the control unit.

 

[wkearney99]

You should be able to use the Garmin to see if the Keypower unit is showing up on the N2K network: https://www8.garmin.com/manuals/web...UID-839F3EF3-13AD-4BFD-892F-57E8A40E55B7.html

Where is your GPS information being generated? What else is on the N2K bus?

And what specifically is Keypower expecting as a source for "speed"? Because there's SOG (speed over ground) which is usually calculated from GPS. There's also STW (speed through water) which is typically generated from a paddlewheel speed sensor, typically part of a through-hull Depth-Speed-Temp unit. STW is perhaps more important as you want to know the actual speed of the water moving under the hull. STW and SOG can be different if you've got a current/tide involved.

 

[magna 6882]

while everything on the boat is 2k the stabilizer control is not. Its is using nmea0183. The garmin does output nmea0183. I think i just need to double check my connections and verify the sentences.

 

[wkearney99]

It'd be good to check with Keypower which PGN sentences it needs. These are what the Garmin claims to transmit:
https://www8.garmin.com/manuals/web...UID-891D6EC7-169E-4146-8279-8400626217D0.html


The Garmin needs to translate the PGNs needed for the Keypower from N2K to 0183.
https://www8.garmin.com/manuals/web...UID-A95F26FF-610B-4B36-93C8-3BB868B71348.html

And you need the 0183 port set to the correct speed.
https://www8.garmin.com/manuals/web...UID-19EA7D28-D200-4DD1-BB24-CB70319A50F1.html

The 8612 only has one 0183 in/out port, if you have other stuff that needs 0183 you may have complications.

 

[magna 6882]

I have three 8612s . I pulled the closest one to my endpoint and installed the adapter cable for this devise. Are you thinking i need to check the other mfds to confirm they dont have an adapter connected? What confuses me is the whole system is networked together. The ais,radar.
,gps,weather station,gps,vhf radio,steering ect are all running off the backbone.

 

[magna 6882]

If i am unsuccessful getting the garmin to play with keypower could i use the vesper 0183 output.It looks straight forward and outputs the VTG sentence?

 

[twistedtree]

wkearney99's suggested on the Garmin settings looks good.


1) Set the port type/config to NMEA Std


2) Set the port speed to 4800 baud. This is the NMEA standard, but it would be good to confirm this is what Keypower is looking for, and/or how to adjust it.


3) Turn on sentences. If you know which sentences Keypower is looking for, then turn those sentences on. Worst case, turn them all on one by one until the keypower is happy.


When checking your wiring, remember you want to use the NMEA Out wires on the Garmin, and connect plus to plus, and negative to negative.

 

[wkearney99]

It all starts with what the control device for the stabilizer wants, and what can provide it.

What PGNs and at what speed.

That's why I asked about the available sources for the information, and pointing toward the online documentation from Garmin.

The combo connector on the Garmin and 0183 introduces the added requirements of correct wire connections, input/output aka transmitter/receiver, you're sending from the Garmin and receiving on the Keypower (and I don't know if the Keypower transmits anything). 0183 is relatively simple but not "plug-and-play". You need to make sure the sending pin from the Garmin is connected to the receiving pin on the Keypower, and vice-versa for the sending pin on the Keypower to the Garmin. Then it's down to setting the correct output speed on the Garmin, and configuring it to send the proper PGNs.

The Garmin can be networked three different ways, typically N2K to the sensors (and they are typically strung all along one continuous bus), ethernet between the 8612's (and radar iirc) and 0183 in/out to any 'old school' devices that still use it. The 8612 can 'share' what comes in/out the 0183 and other networked devices.

This is how other vendors do it as well. Data can come in/out through the chart plotter connections and be shared. Depending on how it's arranged it can mean that some data would only be available if the 'hosting' chart plotter was on. My old Navnet3D setup worked that way. One chart plotter handled N2K to Furuno Ethernet, and another handled 0183 in/out also back over the Furuno Ethernet to the other plotters. It did require specific configuration differences on each of the 'hosting' plotters to handle the port speeds and PGNs being re-sent.

 

[wkearney99]

If i am unsuccessful getting the garmin to play with keypower could i use the vesper 0183 output.It looks straight forward and outputs the VTG sentence?

Bear in mind you want to know that your devices are getting their data consistently and reliably.

I'd be more inclined to use the chart plotters for the interfacing, as they're more likely to be what the Keypower folks expect as a data source. But, again, it depends entirely on the full range of what sentences the Keypower needs.

And you DO NOT want to have more than one device supplying 'the same' information without added configuration steps. You can have multiples on N2K but you need to make sure they've got unique IDs set up on them. I have two different GPS and three different sources for heading on my N2K network. SCX20 sat compass, regular GPS puck, heading sensor and a combo weather unit. If I had a failure of the sat compass I could re-configure the chart plotters to use the other sensors for GPS and heading. But if I didn't have them configured properly there'd be a fair bit of confusion about which one was the proper source.

The same thing applies for any 0183 talkers/listeners and the chart plotters or other bridges that might be translating them.

 

[magna 6882]

Hello all. Turns out the garmin nmea0183 output on the 8600 series is using rs132. though some experimenting and checking voltage i got it working.This configuration only required the use of two wires the +and-. Once i got this sorted out i just set the sentence i needed and it worked.I was surprised since i really had no idea what i was doing but had read the rs protocols developed with increasing voltages and i got less then 2 volt from the garmin so that led me down the rs232 path.Hopefully this thread will help others in the future.

 

[AnsleyS]

Congratulations on the fix and thanks for sharing it with us.